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- Visualization and Applications II
- High Speed Video Techniques
- Holography and Interferometry VI
- Visualization and Applications III
- Framing/Streak Cameras Converters/Cameras III
- Holography and Interferometry II
- Visualization and Applications II
- Holography and Interferometry I
- Visualization and Applications III
- Framing/Streak Converters/Cameras II
- Framing/Streak Camera-Applications
- Poster Session
- Holography and Interferometry II
- Holography and Interferometry VI
- Opto-Mechanical Cameras and Systems I
- Framing/Streak Camera-Applications
- Holography and Interferometry II
- Gated Intensifiers
- Framing/Streak Converters/Cameras II
- Laser and Light Sources I
- X-Ray Techniques I
- Visualization and Applications II
- Poster Session
- Opto-Mechanical Cameras and Systems I
- Visualization and Applications II
- Holography and Interferometry VI
- Poster Session
- Framing/Streak Cameras Converters/Cameras III
- Poster Session
- Framing/Streak Cameras Converters/Cameras III
- Poster Session
- Visualization and Applications II
- X-Ray Techniques I
- Holography and Interferometry I
- Opto-Mechanical Cameras and Systems II
- Visualization and Applications IV
- Visualization and Applications III
- Gated Intensifiers
- Framing/Streak Cameras Converters/Cameras III
- Visualization and Applications V
- Poster Session
- Visualization and Applications IV
- Poster Session
- Framing/Streak Converters/Cameras II
- Poster Session
- Framing/Streak Converters/Cameras I
- Poster Session
- Visualization and Applications V
- Picosecond and Femtosecond Techniques
- High Speed Video Techniques
- Poster Session
- Holography and Interferometry VI
- High Speed Video Techniques
- Visualization and Applications III
- Holography and Interferometry I
- Opto-Mechanical Cameras and Systems I
- Image and Data Processing
- Holography and Interferometry II
- Visualization and Applications I
- Framing/Streak Converters/Cameras II
- Framing/Streak Cameras Converters/Cameras III
- Holography and Interferometry II
- Opto-Mechanical Cameras and Systems I
- Poster Session
- Laser and Light Sources I
- High Speed Video Techniques
- Laser and Light Sources I
- Poster Session
- Framing/Streak Converters/Cameras I
- Framing/Streak Cameras Converters/Cameras III
- Framing/Streak Camera-Applications
- Picosecond and Femtosecond Techniques
- Framing/Streak Converters/Cameras I
- Framing/Streak Converters/Cameras II
- Visualization and Applications IV
- Framing/Streak Converters/Cameras IV
- Opto-Mechanical Cameras and Systems II
- Gated Intensifiers
- Image and Data Processing
- Opto-Mechanical Cameras and Systems II
- Visualization and Applications IV
- Poster Session
- Laser and Light Sources I
- Framing/Streak Camera-Applications
- Visualization and Applications IV
- High Speed Video Techniques
- Visualization and Applications V
- Framing/Streak Converters/Cameras I
- Framing/Streak Converters/Cameras II
- High Speed Video Techniques
- Laser and Light Sources I
- Poster Session
- Picosecond and Femtosecond Techniques
- Framing/Streak Cameras Converters/Cameras III
- Picosecond and Femtosecond Techniques
- Framing/Streak Converters/Cameras II
- Framing/Streak Camera-Applications
- Picosecond and Femtosecond Techniques
- Framing/Streak Converters/Cameras I
- Framing/Streak Camera-Applications
- Gated Intensifiers
- Visualization and Applications V
- Visualization and Applications II
- Holography and Interferometry II
- Opto-Mechanical Cameras and Systems I
- Opto-Mechanical Cameras and Systems II
- Framing/Streak Cameras Converters/Cameras III
- Framing/Streak Converters/Cameras IV
- Picosecond and Femtosecond Techniques
- Framing/Streak Converters/Cameras IV
- Framing/Streak Cameras Converters/Cameras III
- Framing/Streak Converters/Cameras IV
- Gated Intensifiers
- X-Ray Techniques I
- Holography and Interferometry VI
- Framing/Streak Converters/Cameras IV
- Holography and Interferometry VI
- Visualization and Applications IV
- Image and Data Processing
- Framing/Streak Converters/Cameras I
- X-Ray Techniques I
- X-Ray Techniques II
- X-Ray Techniques I
- X-Ray Techniques II
- X-Ray Techniques I
- Poster Session
- Image and Data Processing
- Visualization and Applications I
- Visualization and Applications II
- Framing/Streak Cameras Converters/Cameras III
- Framing/Streak Converters/Cameras II
- Framing/Streak Camera-Applications
- Poster Session
- Visualization and Applications V
- Poster Session
- Visualization and Applications III
- Visualization and Applications IV
Visualization and Applications II
Propagation of the spherical short-duration shock wave in a straight tunnel
Jae Woon Ahn,
So Young Song,
Jun Wung Lee,
et al.
Show abstract
Propagation processes of shock waves incident at the entrance of the straight shock tube have been photographed with a high-speed camera and pressure-time profiles have been recorded with piezoelectric gages. It is concluded that the shock front repeatedly changes a convex to a concave and vice versa with a series of damped oscillations and becomes a stable plane shock front determined by experimental conditions. Good agreement is found between the calculated and measured shock wave interaction angle and the velocity of the Mach stem for the region located up to 24 cm from the entrance. There is considerable difference between the calculated and measured pressure near the entrance of a shock tube but as the shock wave propagates farther, the difference becomes small and remains within the range of experimental error.
High Speed Video Techniques
Fourth-generation motion analyzer
Kris S. Balch
Show abstract
A motion analyzer is used to capture images from a high speed video camera and store the images in real-time for
review. Once the images are stored, they may be reviewed in slow motion while quantitative measurements can be
made for analysis. Motion analyzers are powerful tools for industry and science for viewing high-speed subjects. A
subject could be virtual anything which moves faster than the eye can perceive. Industrial imaging of high speed
subjects can provide the understanding for improving quality, trouble-shooting a problem, increasing capacity, reducing
set-up time, and advancing research. Companies throughout the world are using motion analyzers to remain
competitive.
The evolution of motion analyzer technology can be delineated by frame rate and the sophistication of features. There
have been three generations over the last three decades. This year, the start of a new decade, a 4th generation motion
analyzer is now available.
This high speed motion analyzer was announced at Hannover, Germany this year. It provides the end user with new
analysis opportunities not before feasible. Previous generations of motion analyzers have been limited in their recording
techniques. Based on industrial experience with motion analysis, new image capturing techniques have been
developed. These image capturing techniques are well suited for imaging repetitive processes, continuous flow
processes, controlled events, uncontrolled events and varying demand events.
This paper will describe the technical evolution of motion analyzers including the new 4th generation. Key features
and technologies in this 4th generation motion analyzer will be described. The basic image capture techniques will
be explained along with the motion analyzer's architecture. Also, an overview of new opportunities for analysis on
difficult applications that previous motion analyzer generations have not satisfied.
Holography and Interferometry VI
Collapsing cavities in reactive and nonreactive media
Neil K. Bourne,
John E. Field
Show abstract
This paper presents results of a high-speed photographic study of cavities collapsed asymmetrically by
shocks of strengths in the range 0.26 GPa to 3.5 GPa. Two-dimensional collapses of cavity
configurations punched into a 12% by weight gelatine in water sheet, and an ammonium nitrate/sodium
nitrate (AN/SN) emulsion explosive were photographed using schlieren optics. The single cavity
collapses were characterized by the velocity of the liquid jet formed by the upstream wall as it was
accelerated by the shock and by the time taken for the cavity to collapse. The shock pressure did not
qualitatively affect the collapse behaviour but jet velocities were found to exceed incident shock velocities
at higher pressures. The more violent collapses induced light emission from the compressed gas in the
cavity. When an array of cavities collapsed, a wave, characterized by the particle velocity in the medium,
the cavity diameter and the inter-cavity spacing, was found to run through the array. When such an array
was created within an emulsion explosive, ignition of the reactive matrix occurred ahead of the collapse
wave when the incident shock was strong.
Visualization and Applications III
Damage to polymer-coated glass surfaces by small-particle impact
Mohammad Munawar Chaudhri,
Alan L. Smith
Show abstract
A high speed photographic investigation of the impact damage processes of soda-lime glass
surfaces coated with thin layers of a self adhesive tape and polyurethane rubber has been described. The
impacting particles were 1-mm steel spheres and had velocities in the range of 50-250 ms1. The
photography was performed at a framing rate of 1 million per second. It is shown that, depending upon the
impact velocities, the coatings debonded and perforated by the impact and therefore they provided very little
protection to the coated surface. The coatings also tended to adhere to the projectile and during its rebound
this caused tensile stresses normal to the impacted surface. Additional tensile stresses during the projectile
rebound were caused by the rapid contraction of the piled up coating. These stresses are probably
responsible for the enhanced growth of the lateral cracks in the coated glass surfaces. The coatings,
however, reduced the amount of jetting' of the fragmented material and the removal of the surface chips
developed during unloading.
Framing/Streak Cameras Converters/Cameras III
New electron optic for high-speed single-frame and streak image intensifier tubes
Boris Efimovich Dashevsky
Show abstract
A new design concept of the electron-optical focusing system for widescreen single-frame and streak image intensifier tubes with the gating-deflection-type shutter system is presented. The effectiveness of a 'quasispheric' immersion objective for forming of widescreen image has been studied using a numerical model. This objective is used in a new LD-F-5 tube with a useful photocathode area of 40 mm and LD-S 10 streak image inverter tubes. The spatial resolution of LD-F-5 tubes is about 25lp/mm under the strobe pulse duration of about 10 ns and voltage +/- 350 V.
Holography and Interferometry II
Instantaneous measurement of density from double-simultaneous interferograms
Show abstract
The visualization technique presented herein is based on white light differential interferometry using large Wollaston
biprisms. The particularity of our set-up is that it yields two instantaneous interferograms, taken at precisely the same time,
on which the interference fringes are differently oriented. Thus, the instantaneous fields of two different partial derivatives of
density are simultaneously recorded and it is possible, through the use of both, to obtain the value of the density in domains
where this cannot be done using a single interferogram. This method has been successfully tested in the two-dimensional
unsteady flow past a cylinder.
Visualization and Applications II
Analysis of results from high-speed photogrammetry of flow tracers in blast waves
Show abstract
To describe all the physical properties in blast waves at any fixed point it is necessary to independently measure the time variation at that point of at least three of the physical properties. High-speed photography of smoke tracers established adjacent to the explosive charges was used to measure the particle trajectories in blast waves from a large number of air burst and surface burst explosions. To describe the trajectory of a spherical piston the trajectory of a smoke tracer which was initially close to the charge was used in a numerical simulation. The trajectories of massless particles were calculated at initial positions identical to those of the other flow tracers in the experiment.
Holography and Interferometry I
Multipass holographic interferometry for low-density gas flow analysis
Jean Surget,
S. Georges Duvant
Show abstract
Holographic interferometry is a well known method currently used for supersonic
gas flow analysis. However, its sensitivity is not high enough to measure low
density gas flow, such as those existing in the hypersonic domain. In order to
increase the sensitivity, a versatile multipass set-up has been built. Three
different methods for selecting a given light pass number, through the wind tunnel
test section, have been investigated thanks to a few modifications of the optical
set-up. The proposed paper will describe the holographic set-up and the three
techniques for passage number selection of the test beam through the studied
phenomenon. The results obtained both in laboratory and in a low pressure wind
tunnel will be presented.
Visualization and Applications III
Investigation of diesel injection jets using high-speed photography and speed holography
Fritz Eisfeld
Show abstract
To reduce the particle emission of a Diesel engine it is necessary to improve our know-
[edge on the penetration and the spreading of an injection jet. Therefore the motion of
the fuel jet and his break up within the orifice and aLso in a test chamber was investigated
using high speed cinematography. The possibility to use high speed holography was aLso
tested and a new drum camera was developed.
Framing/Streak Converters/Cameras II
New streak tube with femtosecond time resolution
Gregory G. Feldman,
T. A. Ilyna,
I. N. Korjenevitch,
et al.
Show abstract
Here has been considered a design of new femtosecond tube. Focusing system of the tube is manufactured as a
couple of electromagnetic lenses, their coils are switched in contrary configuration. The tube is supplied with two deviating
systems: a signal one, manufactured as a symmetric meandric line and an additional one. condencer type.
At general accelerating voltage 10 kV field intensity reaches in the zone near cathode 15 kV/mm. Calculated temporary
tube resolution is 100 fs.
Framing/Streak Camera-Applications
High-speed photographic study of impact on fibers and woven fabrics
John E. Field,
Q. Sun
Show abstract
The paper describes a study of the behaviour of fibres and woven fabrics when impacted at velocities in
the range up to - l000m 1. The projectiles, typically steel balls of 2 or 5mm diameter, were accelerated
by a double diaphragm gas gun which allowed velocities to be controlled within a few metres per second.
The impact events were viewed using high-speed photography. Photography at microsecond framing
intervals was made using an image converter camera (the Hadland Imacon). This camera was triggered
when the projectile interrupted a laser beam positioned just in front of the specimen. In experiments with
single fibres, it was possible to measure the transverse wave speeds. Experiments were made with a
number of fibre materials covering a wide range of moduli and strength properties. A number of
experiments were also made with woven fabrics of different densities and laminates. The velocity range
covered included non-penetrating and penetrating events. The fibre materials which had the best ballistic
performance were those which combined a high dynamic modulus with the ability to reach large strains
before failure. The high modulus is important since it affects both the strength and the stress wave
velocities. If a material has high wave velocities it can spread the load onto other fibres and layers more
quickly which is beneficial.
Poster Session
Experimental research on the casing-shaped charge
Er-xin Gao
Show abstract
,00xT pulaed X-ray photograph had been used to research on the collapsing
process of the casing shaped charge and the pictures of eJ'iaper after detonation
were got by the pulsed X-ray photograph.In this article,the experimental curves
of collapsing process had been given by experimental analysis and it is found
that the main deforining process of shaper were the radial expansion and the
axial retreat.
Holography and Interferometry II
Pulsed holographic and speckle interferometry using Hopkinson loading technique to investigate the dynamical deformation on plates
Show abstract
In our presentation we will concentrate on the dynamical experi
mental techniques about the deformation of the finite-circular metal
plates after normal impact . Holographic interferometry and defocused
speckle photography are applied to get the full field response.
Synchronization is accomplished with the electronical equipment
specially designed by author. A new loading apparatus is developed to
determine the transverse impact waveforms.
Holography and Interferometry VI
Diagnostic of the reaction behaviour of insensitive high explosives under jet attack
Show abstract
Definitive conclusions about high and low order reactions can be
drawn from individual framing-mode pictures of a rotating mirror
camera record, when both the velocity of the axial propagation of the
reaction along the outer contour and the velocity of radial products
are analyzed at various distances from the plane of initiation. In
this, the intensity of the reaction can be assessed quantitatively
from the radial expansion velocities, even when, for example, a penetrating
shaped charge jet induces a bow wave in the test charge.
A detailed description is given of the test set-up and of the test
results obtained with charges exposed to the impact of a shaped charge
j et.
Opto-Mechanical Cameras and Systems I
Advances in the practical application of schlieren photography in industry
Horst R. Herbrich
Show abstract
The handling of schlieren investigation equipment as well as the image recording
technique has been improved.
In the past, the object to be investigated usually had to be brought to the
permanently installed schlieren apparatus, a procedure which was often not only
complicated but even costly. Two schlieren methods (the parallel beam and coincidence
beam principle) have been modified in such a way that they can be used
in the form of portable equipment on-the-spot wherever needed. This also makes
it simple to carry out schlieren investigations on bulky (stationary) objects, for
example in the industrial development and production sectors.
For the quantitative analysis of schlieren movements (e.g. path/time analyses
for measuring speed), the slit and knife edge should be arranged perpendicular to
the direction of schlieren movement in order to obtain accurate measuring results.
With the majority of schlieren equipment, adaptation of the slit and knife edge
position to a different direction of schlieren movement involves time-consuming
adjustment work. This cannot be done while an image is being recorded. For this
reason, a schlieren investigation apparatus (coincidence principle) is described
with which these disadvantages are obviated. The slit and knife edge position can
be adapted to a different direction of the Schlieren during a video or film recording
without any adjustment being necessary. This is made possible due to the fact
that the light source, condensing lens, slit and knife edge set-up can be revolved
by 360 degrees around the optical axis of the sperical analyzing mirror.
Framing/Streak Camera-Applications
Digital readout for image converter cameras
Joseph Honour
Show abstract
There is an increasing need for fast and reliable analysis of
recorded sequences from image converter cameras so that
experimental information can be readily evaluated without recourse
to more time consuming photographic procedures.
A digital readout system has been developed using a randomly
triggerable high resolution CCD camera, the output of which is
suitable for use with IBM AT compatible PC.
Within half a second from receipt of trigger pulse, the frame
reformatter displays the image and transfer to storage media can be
readily achieved via the PC and dedicated software.
Two software programmes offer different levels of image
manipulation which includes enhancement routines and parameter
calculations with accuracy down to pixel levels. Hard copy prints
can be acquired using a specially adapted Polaroid printer, outputs
for laser and video printer extend the overall versatility of the
system.
Holography and Interferometry II
Simultaneous imaging and interferometric turbule visualization in a high-velocity mixing/shear layer
Show abstract
A single-jet supersonic mixing/shear layer simulator in which two high speed video data acquisition systems simultaneously sample the flow region has been used to characterize the structure of turbulence in a high-speed mixing/shear layer and its degradation effect on an optical test beam. The experiment imaged a point source through the flow field. Correlations are shown to exist between the turbulent structure of the flow field and specific aerooptic distortions, offering the foundations for real time error correction of optical degradations associated with hypersonic flight.
Gated Intensifiers
Sub-100 psec x-ray gating cameras for ICF imaging applications
Show abstract
The glass laser Inertial Confinement Program in the USA has made significant achievements in laser compression of
capsules filled with thermonuclear fuel. To achieve a high degree of implosion, a symmetric irradiation is essential
and is achieved by a large number of smoothed laser beams directly impinging on a target or by indirect drive(1 '2)•
The key diagnostic used to monitor arid adjust the symmetry of indirect drive at LLNL and to some extent direct drive
at LLE is time resolved two dimensional x-ray imaging, which allows the experimentalists to observe in emission
the symmetry of the imploding shell during the implosion phase, and the size and shape of the hot fuel in the
stagnation phase. An example of a sequence of 14 images graphically illustrating a direct drive implosion with a
well balanced direct drive laser system is shown in Fig. 1.
The need for this capability has focussed the high speed photography effort at LLNL and LLE. In the last several
years, demonstrated that 80 Ps x-ray gating with 30 mm detector plane resolution is routine, and 35 ps x-ray gating
has been achieved and will soon be in routine use soon.
Electro optic tubes can achieve x-ray gating but the limited spatial and temporal resolution(3' 4), caused us to focus
our effort on the gating of microchannelpiate (MCP) proximity focussed x-ray detectors. The only significant
disadvantage of the gating MCP's over electro-optical tubes is that many images on exactly the same line of sight
cannot be achieved. However, multiple images with gated MCP's can be obtained along the lines of sight which are
insignificantly different from each other, with spatial and temporal resolution that are more than adequate. Most
importantly, gated MCP detectors are sufficiently practical that several of them are in routine use on large laser
systems such as the Nova glass laser at LLNL and the Omega glass laser at LLE.
In this paper we report on several of the technical advances made at LLNL in the gating of MCP x-ray detectors over
the past two years, and show typical results obtained from implosions.
The essential features of a gated MCP detector are shown in Fig. 2. A pulsed voltage (typically 1 kV, 100 psec) is
applied across a MCP. The voltage is applied by gold conducting layers on the MCP, which form a microstrip line
with the glass of the MCP being the dielectric(5). While the voltage is applied the photo electrons resulting from xray
photons incident on the coated surface of the MCP are amplified with typically i03 gain. Because the gain is
non-linear with the applied voltage, (subject to consideration on the electron transit line in the MCP, Section IV)
there can be narrowing of the 'optical' gate with respect to the electrical gate. This relaxes the pulse voltage
requirement for the MCP, to FWHM -100 psec, and voltages of typically 1 kV into typically 25W(6).
In section II we discuss the novel approach we use for the generation of the electrical pulses required for the gated
MCP cameras. The spatial resolution and the factors affecting it are described in Section III. We discuss the
temporal resolution of the MCP detectors in Section IV, and in Section V we discuss the configuration of microstrip
coating on MCP detectors we have used and some typical results from laser driven implosions. Off line tests
showing ultra font gating are described in section VI.
Framing/Streak Converters/Cameras II
Femtosecond streak tube
Show abstract
A new femtosecond streak tube is proposed aiming at good time resolution. Based on the
idea, the tube has been designed and computer simulations on the electron trajectory, which
includes dynamic operation of the sweeping electrode, have shown that the tube has
theoretically time resolution of 5Ofs.
Laser and Light Sources I
Application of high-speed infrared emission spectroscopy in reacting flows
Guenter Klingenberg,
Helmut Rockstroh
Show abstract
Multichannel near-infrared (NIR) spectroscopy is used to investigate two-phase, reacting flows. The spectral range is 1.2 to 5.3 microns. The NIR emission produced by the combustion of prepressurized gas mixtures consisting of hydrogen/oxygen/helium and carbon monoxide/oxygen is recorded by linear, 96 element, InSb diode arrays. Maximum time resolution is 1 ms for a full spectrum. The method has the potential for time resolved species analysis of instationary combustion reactions at high pressures.
X-Ray Techniques I
Flash soft radiography: its adaption to the study of breakup mechanisms of liquid jets into a high-density gas
Peter Krehl,
D. Warken
Show abstract
Liquid-jet development, structure, propagation and disintegration radiographic characterizations require thicker X-ray windows as test chamber pressures increase; these windows absorb soft X-rays and diminish image contrast. Attention is presently given to a high-intensity flash soft X-ray generator with 120 nsec pulse duration at FWHM. The levels of imaging performance thus achievable are illustrated by various flash radiographs of liquid-injection phenomena taken at 1 and 100 bar pressures.
Visualization and Applications II
Wire explosion at reduced pressures
Eun Soo Lee,
So Young Song,
Kyu Soo Jhung,
et al.
Show abstract
Explosion phenomena of silver wires at reduced environmental air pressures have
been investigated by applying oscillo-streak photographic technique, which has been
designed for more exact temporal correlation between the oscilloscopic and streak
records. Expanding speeds of metal cloud and shock wave increase at reduced pressure.
However, for constant wire and discharging circuit parameters, traces of currents and
voltages are not altered until the breakdown through metal cloud or air takes place.
The critical pressure, below which the air surrounding metal cloud breaks down before
the wire has been ruptured completely, has been found to be dependent on wire length
and peak voltage induced during the rupture process in atmospheric condition. The
empirical relationship between the ambient pressure, breakdown voltage, and wire
length implies similarity between the breakdown of air ahead of the expanding metal
cloud and the surface flash over of insulator at low pressure. Present results could
support the concept that a metal wire bursts into nonconducting metal particles on
the surface of the wire and the disintegration proceeds toward the wire axis.
Poster Session
Laser high-speed photography in cylindrical charge shell burst process
Guozhu Li,
Wenming Wu,
Degong Su
Show abstract
The structure and principle of the explosive device is described simply.all the
process during this test is recounted in detai 1 .and the results of the test are
analysed in this article.
The test device is a colurnn.with a diameter of 150mm and a length of 300mm. which
shell is made of a steel or a glass fibre reinforce plastic.with a thickness of
5mrn.in it there is prefab filler.ln the centre of the shell,there is a cylindrical
high energy explosive,and in the end there is a high voltage exploder. The test
device is illuminated by the laser pulse produced with a ruby sequential pulse
laser. The record is conducted by a high speed camera Type GSJ.The test device. the
sequential pulse laser generator and the high speed camera are synchronized by a
self-made synchronizer .In al 1 the process three pictures are taken which interval
are 48js.Therefore.the conclusion can be obtainned. that is.the test device bursts
in symmetry and shaped like drum.and then it flies off, so t.hat some useful
information is offered for studyimg and design of explosive device.
Opto-Mechanical Cameras and Systems I
Ratio-telecontrolled strobolume for high-speed photography of depressurized towing tanks
Wenzheng Lin,
Aibao Jiang,
Meizhen Zhuo
Show abstract
Recently. a novel ratio- tclccontrollcd strobolunic has been developed that allows us to obtain
synclito- flash illumination for moving O1)jCCtS in moist and dcpressurized environment its pricipal
pararnetes are summarized as follows: flash freguency, O-lOOp.p.s; discharge energy, 1O-60J, flash
pulse width, 2-3.5/is; flash phase control range 0-360 ° In this paper, a briefintroduction is given
01't (lie conflgura(ioii of the slioholuinc and some experimental results are reported.
Visualization and Applications II
Dynamic photoelasticity with a split Hopkinson pressure bar
David R. Morris,
A. J. Watson
Show abstract
To observe the behaviour of materials subject to impact shock loads,
accurate high frequency measurements are vital.
The measurement of ultra short pulses (less than 50 microseconds) can
be carried out by means of electrical resistance strain guages
(ERSGs) . The ERSG's also pick up electromagnetic interference signals.
Dynamic photoelasticity was used as a check for the ERSG records.
Dynamic photoelastic tests were carried out using a Barr and Stroud
CP5 high speed rotating mirror camera. The timing of the event and
illumination was critical. Important confirmatory results were
obtained by this technique.
Holography and Interferometry VI
Application of cylindrical blast waves to impact studies of materials
David J. Parry,
H. R. Stewardson,
Salahuddin Ahmad,
et al.
Show abstract
An exploding wire method is described in which the impact properties of hollow polymeric cylinders are investigated by subjecting them to internal, high-pressure, blast wave loading. Studies of the blast waves themselves, and of the expansion of thin-walled polymer tubes and rings, have been made using high-speed image convertor photography at 10 exp 5 to 10 exp 6 frames/s. Such observations, when combined with strain gauge and pressure measurements where necesary, have enabled the mechanical properties of several polymers to be determined at high strain rates from 10 exp 3 to 10 exp 5/s.
Poster Session
Subnanosecond high-speed framing of prebreakdown phenomena
Wolfgang Pfeiffer,
Dieter Stolz,
P. Zipfl
Show abstract
This paper describes an optical diagnostic system for the subnanosecond time range.
The system consists of three main parts; a gated image intensfier tube with dual
microchanel - plate (MCP), a low light level CCD - camera and a triggerable digital video
frame store.
With this system an exposure time of 0.8 ns, a shutter ratio of more than 1 O and a
gain greater than iO can be achived. The spatial resolution of the system is 10 lp/rnm.
The used camera system allows to trigger the digital frame store at the beginning of the
frame. The digital frame store is connected to a personal computer, thereby a very
comfortable image analyzing system is established.
This optical diagnostic system allows the direct measurement of the radiation emitted
during an electrical breakdown of a spark pap. The optical analysis provides important
information about the breakdown mechanism '
Framing/Streak Cameras Converters/Cameras III
Modular streak camera for laser ranging
Show abstract
The perspecitves of the use of a streak camera as a laser ranging system
detector is discussed. The development and construction of an modular design streak
camera dedicated for laser ranging is described. Both linear and circular sweep
modifications have been tested. The first experimental results of a ground target
laser ranging are presented.
Poster Session
Application of high-speed photography to the study of high-strain-rate materials testing
D. Ruiz,
John Harding,
J. P. Noble,
et al.
Show abstract
There is a growing interest in material behaviour at strain rates greater than 104sec1, for instance in the design of aero-engine turbine blades.
It is necessary therefore, to develop material testing techniques that give well-defined information on mechanical behaviour in this very high
strain-rate regime. A number of techniques are available, including the expanding ring test1, a miniaturised compression Hopkinson bar technique
using direct impact and the double-notch shear test3 which has been described by Nicholas4 as "one of the most promising for future studies
in dynamic plasticity". However, although it is believed to be a good test for determining the flow stress at shear strain rates of 104sec and
above, the design of specimen used makes an accurate determination of strain extremely difficult while, in the later stages of the test the deformation
mode involves rotation as well as shear. If this technique is to be used, therefore, it is necessary to examine in detail the progressive
deformation and state of stress within the specimen during the impact process. An attempt can then be made to assess how far the data obtained
is a reliable measure of the specimen material response and the test can be calibrated. An extensive three stage analysis has been undertaken. In the first stage, reported in a previous paper5, the initial elastic behaviour was studied.
Dynamic photoelastic experiments were used to support linear elastic numerical results derived by the finite element method. Good qualitative
agreement was obtained between the photoelastic experiment and the numerical model and the principal source of error in the elastic region of
the double-notch shear test was identified as the assumption that all deformation of the specimen is concentrated in the two shear zones. For
the epoxy (photoelastic) specimen a calibration factor of 5.3 was determined. This factor represents the ratio between the defined (nominal) gauge length and the effective gauge length.
The second stage of the analysis of the double-notch shear (DNS) specimen is described in this paper. This consists of the use of ultra-high speed
photography to provide information on the plastic deformation behaviour of the specimen. Two different high speed cine cameras were used
for this work, a Hadland "Imacon" 792 electronic image converter camera and a Cordin 377 rotating mirror-drum optical camera. Implementation of the two cameras and photographic results are briefly compared and contrasted here.
Stage three of this work consists of an advanced numerical analysis of the elasto-plastic, strain rate dependent behaviour of the DNS specimen.
The principle intention of the authors was to use the physical data collected from high speed photographs for correlation with this work. Full
details of the numerical work are presented elsewhere6 but some salient results will be given here for completeness.
Framing/Streak Cameras Converters/Cameras III
Application of a linear picosecond streak camera to the investigation of a 1.55 um mode-locked Er3+ fiber laser
Show abstract
A modified Imacon type streak camera with temporal resolution of 1.5 psec was used for the measurement of pulses generated by a mode locked Er fiber laser operating at 1.55 micron wavelength. The specially developed S1-PV001 image tube had an initial sensitivity of 26 mu A/W at 1.3 micron. To improve the signal to noise ratio for recording low level CW laser radiation additional shutter circuitry was added to the Imacon camera electronics. The camera was operated at 15 Hz repetition rate, triggered by a sample of the RF signal used for driving the acoustooptic mode locker. A very sensitive and simple recording system was used for recording the time dispersed pictures generated in the ICT output screen using a high gain PMT and a 150 micron slit mounted on a translation stage. The signal from the PMT was read with a box car averager and sent to a PC type computer which controlled the translation stage. The acoustooptically mode locked Er fiber laser can generate pulses of 80 psec in CW operation with a peak power of 0.6 W.
Poster Session
Low-cost high-quality range camera system
Derek Sewell
Show abstract
Projectiles in flight and explosives detonating underwater can be studied
using this range camera system, which yields high quality shadowgraph images.
Measurements are allowed of: the velocity, profile and attitude of projectiles
in flight; the profiles of the cavities made by bare and shaped charges
underwater; and the shock fields associated with these events. The cost of
each complete camera station was approximately £6000 when built.
Miniaturized semiconductor light source system for Cranz-Schardin applications
Show abstract
A digitally controlled miniature semiconductor light source system for Cranz-Schardin applications
has been developed. The light pulse power is up to 1 W. The maximum framing frequency is 10 MHz.
Application examples for photographic and CCD camera recording are given.
Visualization and Applications II
Application of high-speed photography to chip refining
Mustafa I. Stationwala,
Charles E. Miller,
Douglas Atack,
et al.
Show abstract
Several high speed photographic methods have
been employed to elucidate the mechanistic aspects of
producing mechanical pulp in a disc refiner. Material
flow patterns of pulp in a refmer were previously
recorded by means of a HYCAM camera and
continuous lighting system which provided cine pictures
at up to 10,000 pps. In the present work an IMACON
camera was used to obtain several series of high
resolution, high speed photographs, each photograph containing an eight-frame sequence obtained at a
framing rate of 100,000 pps. These high-resolution
photographs made it possible to identify the nature of
the fibrous material trapped on the bars of the
stationary disc. Tangential movement of fibre floes,
during the passage of bars on the rotating disc over
bars on the stationary disc, was also observed on the
stator bars. In addition, using a cinestroboscopic
technique a large number of high resolution pictures
were taken at three different positions of the rotating
disc relative to the stationary disc. These pictures were
computer analyzed, statistically, to determine the
fractional coverage of the bars of the stationary disc
with pulp. Information obtained from these studies
provides new insights into the mechanism of the
refining process.
X-Ray Techniques I
Applications of a soft x-ray streak camera in laser-plasma interaction studies
George D. Tsakiris
Show abstract
The soft x-ray streak camera system XRSC-II developed at the Max-Planck Institut fuer
Q uantenoptik has been used for some time now in experiments aiming at the study of high
density, high temperature laser produced plasmas. To this end, various experimental arrangements
have been employed. For example, the combination of an imaging slit aperture and the
XRSC-II has produced records of transient x-ray sources with a temporal resolution of 34ps and
spatial resolution of 2OOim . In time-resolved spectroscopic studies, a free-standing transmission
grating in front of the XRSC-II photocathode has proven to be very effective in providing
time-resolved spectra with spectral resolution of 5-10 A . A more complicated setup utilizing an
imaging slit aperture, a free-standing transmission grating and the XRSC-II has been recently
deployed to obtain spatially and temporally monochromatic signals from the burnthrough of
x-ray heated thin Au foils. Examples from different experiments are presented and discussed.
Holography and Interferometry I
Dynamic particle holographic instrument
Guozhi Wang,
Shan Feng,
Zhengrong Wang,
et al.
Show abstract
The sizes, distributions, and speeds of sprayed particles can be ascertained under various circumstances through the use of the in-line/off-axis holography and sequential pulse laser system discussed. The optical system used is of multifunctional architecture, allowing either the making of a reflecting object's hologram or serving as a holographic interferometer for transparent objects and fluid fields. The light source used is a Q-modulated ruby pulse laser.
Opto-Mechanical Cameras and Systems II
New development of friction speeding mechanism for high-speed rotating mirror device
Yan-nian Wei,
Pei-sheng Jiang,
Zeng-xiang Zhang,
et al.
Show abstract
In 1980, our research group had finished the study of a novel FSN, which was
successfully used in the high speed camera of 2.5 million frames/s. The same year, a
paper titled Rotating Mirror Device with Novel Speed-Increase mechanism was given at the
14th International Congress on High Speed Photography and Photonics. In recent years, we
have done a lot of research work both on practical application and theory, and results
are obtained. This paper represents the main results.
Visualization and Applications IV
Development of new beamsplitter system for real-time high-speed holographic interferometry
Yoshitaka Yamamoto
Show abstract
A new beam-splitter suitable for real-time high-speed holographic interferometry
is manufactured and its high performance is confirmed. This beamsplitter
is constructed with an electro-optical phase-modulator,a polarized
prism and a half-wave phase-plate. This system has merits that an arbitrary
intensity ratio of a reference beam and an object beam is obtained with no
mechanical movement and that the intensity ratio is remotely controlled apart
from the beam-splitter.
Visualization and Applications III
Research on macroeffects and micromechanism of martensite phase transition of shape memory alloys by high-speed photography
Jie Yang,
Yuehua Wu,
Yusheng Zhou,
et al.
Show abstract
The paper, b means of High Speed Photography, records the changing
process of helical springs made of Shape Memory Allo(SMA) in thermal
cycles and the whole phase transition process of the material under
microscope. B picture analysis, the paper shows clearly the macro-
effects caused bY thermal elastic Martensite phase transition, reveals
part of the micro-mechanism, obtained a definite relationship between
temperature, deformation and resilient force in the phase transition
process of thermal elastic Martensite and finds out the consistency of
thermal elastic Martensite in the repeated thermal cycles. This will
serve as a reference for the research of memory effect degradation and
phase transition temperature shifting.
Gated Intensifiers
Picosecond intensifier gating with a plated webbing cathode underlay
Stan W. Thomas,
Jimmy C. Trevino
Show abstract
Irising time of microchannel plate intensifiers with fiberopticcathode windows has been reduced to less than 100 ps. This
is achieved by metalizing the fiberoptic's cladding glass to reduce cathode substrata resistance without reducing transmission
of the cathode window.
During irising, a bright ring is seen, first at the edge as it propagates toward the center. This time lag is caused by the
distributed time constant of the substrata resistance and the cathode-to-MCP capacitance. Since the capacitance is fixed by
restraints of tube geometry, our goal was to reduce the distributed resistance sufficiently to achieve sub-nano-second
irising times.
The process involves a number of steps. First, an approximately 34-nm-thick layer of nickel is evaporated over the cathode
side of the fiberoptic window. Next, the nickel is coated with photoresist, which is exposed through the faceplate and the
nickel, using the fiberoptics as a self-aligning mask. The photoresist is developed and washed off, exposing the nickel
covering the active fiber area or core glass. At this point, photoresist still covers the nickel over the cladding glass or
webbing, protecting it when the exposed nickel covering the core glass is etched away. Finally, the remaining photoresist is
removed, leaving only the nickel covering the fiberoptic webbing.
We processed several 18-mm faceplates from ITT, Fort Wayne, Indiana, and ITT used the plates to construct intensifiers
which we tested for irising time. Photographs, as well as computer processed 3-D images of the output showed no irising.
This means that any irising that occurs is clearly faster than the time resolution of our measurement system (which is
estimated to be less than 50 ps).
Subnanosecond intensifier gating using heavy and mesh cathode underlays
Stan W. Thomas,
Alex R. Shimkunas,
Phillip E. Mauger
Show abstract
Irising time of microchannel plaie intensifiers with quartz cathode windows has been reduced to less than 100 ps. This is
achieved by application of a metal underlay to reduce cathode substrata resistance. The first approach uses a 50%-transmissive
Uniform nickel heavy underlay, while the second approach uses a 96%-transmissive nickel mesh.
For the heavy underlay, approximately 5 nm of nickel is evaporated over the cathode side of the quartz window. For the
mesh underlay, approximately 750 nm of nickel is sputtered onto the window and coated with photoresist, which is exposed
through a mask of 100-micron-square spaces defined by 3.5-micron-wide lines. The photoresist is developed and washed off,
exposing the nickel covering the square areas. At this point, photoresist still covers the nickel over the 3.5-micron-wide wires,
protecting them when the exposed nickel covering the squares is etched away. Removal of the remaining photoresist leaves
only the nickel wires, which have been reduced to 2 microns in width due to sideways etching during removal of the squares.
As a prototype effort, Lawrence Livermore National Laboratory (LLNL) purchased two 1 8-mm heavy underlay tubes
from Hamamatsu Photonics and formed a mesh underlay on faceplates which Hamamatsu used for construction of two
additional tubes. Measurements of irising time were made on these four tubes. Irising is characterized by a bright ring, seen
first at the edge as it propagates toward the center. The time lag is caused by the distributed time constant of the substrata
resistance and the cathode-to-MCP capacitance. Since the capacitance is fixed by restraints of tube geometry, our goal was to
reduce the distributed resistance sufficiently to achieve sub-nanosecond irising times. Testing showed no irising on one tube of
each type of underlay. With these encouraging results, LLNL and Nanostructures refined the mesh application technology, and
LLNL procured eight mesh tubes from ITT using meshes formed by Nanostructures. An additional 8 tubes with a 50%
transmissive heavy underlay were procured from Hamamatsu. Testing of these tubes also showed no detectable irising, which
leads us to conclude that tubes can be made with irising clearly faster than the time resolution of our measurement system,
which we estimate to be less than 50Ps.
Framing/Streak Cameras Converters/Cameras III
Avalanche transistor selection for long-term stability in streak camera sweep and pulser applications
Stan W. Thomas,
Roger Lee Griffith,
Alan T. Teruya
Show abstract
We have identified the Motorola 2N4014 and 2N5551 and the Raytheon R53944 as three transistor types that exhibit
avalanche characteristics and have long term collector breakdown voltage stability superior to other transistors tested.
Stability on all types has been improved by power burnin.
An automatic avalanche transistor burnin tester has been constructed to allow power burnin of up to 1008 transistors at
a time. The tester is controlled by an IBM Personal Computer (PC) and can be programmed to acquire data, unattended, at
any desired rate or period. Data are collected from each run and stored on a floppy disk in ASCII format. The data analysis
software, RS/1 , was used for analysis and display.
Data runs were typically 3 to 4 months long, with readings taken weekly. The transistors were biased into the avalanche
or Zener region by individual current sources set to about 20% of the self-avalanche current for each type of transistor.
Motorola, Zetex and National transistors were operated at 100 microamperes (pA), and the Raytheon units were operated at
20 pA. The electric field causes migration of material in the high field region at the surface near the collector-base junction,
creating the voltage instability.
Visualization and Applications V
Visualization study on pool boiling heat transfer
Shuya Kamei,
Masaru Hirata
Show abstract
The visualized boiling phenomena were observed by means of high speed
photographic shadowgraphy using a rotating prism camera (nac HIGH SPEED CAMERA
model-16HD) with the speed of about 3500 frames per second. The photographs show
that pool boiling heat transfer phenomena are varied for the boiling curve based on
the experiments.
Experiments have been carried out to investigate pool boiling heat transfer
phenomena on a horizontal thin filament in subcooled and saturated distilled water.
The experiments were performed for atmospheric pressure,for filament diameters of
about 0.3 mm, for region of natural convection to film boiling.
The color-film made by high speed movie camera are converted to high speed
color video-tape. It is convenient to edit and show the tape for visualization with
teaching the students. The high speed color video showed that the successive motion
and shape of bubbles during their process of detachment varied with increasing heat
flux on the heated surface of a filament.
From these results, it was confirmed that the high speed phenomena of boiling
by the slow motion video pictures could be estimated clearly.
Poster Session
New technologies in lighting systems for high-speed film and photography regarding high-intensity and heat problems
Burkhard Severon
Show abstract
Increasing frame rates and the heat sensibility of test objects forced the development of new lighting systems.
For example at the automotive industry, where continuous light sources are indispensable for the high speed photography of car crash tests and automobile components
tests, the further development of high efficient safety systems, so as Air-Bag systems, needs very datailed analysis of the accelerated motions. Frame rates from
2.000 up to 10.000 frames per second are requested and beside adequate camera systems
and film material, this also means high intensive lighting systems.
The need for high intensity could be easy achieved by the use of additional light
fixtures but the request for more intensity comes along with the problem of heat.
The test objects and the auxiliary materials become more and more temperature-
sensitive. Very offen they have to be used under strict climate conditions. Mainly
there where the test objects are already placed inside the illuminated area, the heat
radiation of the light sources to the test objects have to be reduced.
So high intensive, flicker free and less heat are today's requirements of light
performance. This paper will present solutions to meet those demands.
Visualization and Applications IV
Hycam camera study of the features of a deflagrating munition
Trevor J. Kinsey,
T. J. Bussell,
M. C. Chick
Show abstract
We report on the use of a rotating prism high speed camera (Hycam) in a field study of the early stages of the
breakup characteristics of a deflagrating Composition B loaded 105 mm HE shell. The experiments are part of a
program aimed at assessing candidate processes that may contribute to the mass detonation hazard of explosive
stores. The experimental requirements for the successful observation of the deflagrating shell are described in
detail.
The camera was run at 35,000 to 40,000 pictures per second with a 1/10 shutter fitted. High intensity illumination
of the shell was provided by an array of class S flash bulbs and diffusion screen. Baffles were essential in order to
screen the shell from the expanding products of the shaped explosive charge device used to produce the controlled
deflagration of the shell. The technique successfully allowed the determination of several parameters associated
with the event including shell expansion rate, time to shell burst and initial fragment velocity. Products escaping
from the cracking shell limited the use of the technique for studying shell to shell interactions.
Poster Session
Experimental investigation on the flow behavior of liquid aluminum inside pressure-die-casting dies using high-speed photography
Xuping Jiang,
Guobin Wu
Show abstract
An experimental investigation on the flow behavior of molten aluminium inside the
pressuredie-casting dies for manufacturing electric motor rotors by using flow visualization and high speed photography is reported in this paper. The experiments were
in fact carried out on several models made of organic glass, in which water instead
of liquid aluminium was adopted as the test liquid by virtue of the principle of
dynamic similitude in hydraulics. The observed results obtained from the models show
a reasonable agreement with those from corresponding prototypes, and therefore provide a valuable scientific basis for the design of the casting dies, and for the
selection of technological parameters of the pressuredie-casting and further theoretical analysis.
Framing/Streak Converters/Cameras II
First results on a developmental deflection tube and its associated electronics for streak camera applications
Claude Froehly,
A. Laucournet,
Joseph-Albert Miehe,
et al.
Show abstract
A new compact streak tube and its associated deflection electronics
have been developed. The static and dynamic performances of this
system are examined in singleshot and synchroscan modes.
Poster Session
Automatic film reading system for high-speed photography
Renkui Zhou,
Chongzhen Yu,
Jiankang Ma,
et al.
Show abstract
This paper describes an automatic film reading system for high speed photography
which adopts the principle of measurement of CRT scanning controlled by a microcomputer.
It consists of a CRT scanner, a projector, an irrage processing device, a digitaloptical
measuring platform, a microcomputer system and its software. The system has
two modes , the semi-automatic reading mode and automatic reading mode , which can read
out the image information recorded on 1 6 , 35 or 7Orrm film . The reading accuracy for
coordinates of image point is within 0 .01mm. The reading speed is 1 --20/s
Observation of multiphoton photoemission from a NEA GaAs photocathode
Liming Wang,
Xun Hou,
Zhao Cheng
Show abstract
Cubic responses in photoelectron emission from a , 02 activated GaAs layer,
illuminated by a Q-switched Er ,Thi,Ho : YLF laser ( 2 .O6um) both at room temperature
and at liquid nitrogen temperature ( 77K ) were investigated . Photocurrent density
proportional to the cubic of intensity of incident light over three orders of magnitude
at both temperatures shows not only thatthe electron emission is three-photon
photoemission, but also that thermal emission is nebligible at room temperature in
our case. The photoemissive current from a P-type monocrystal GaAs substrate activated
only by caesium shows six power dependence on light intensity . Comparisons of
measured three-photon photoemission coefficient of GaAs(Cs,02) with a theoretical
estimated values and with four-photon photoemission coefficient of a Cs3Sb photocathode
are given.
Framing/Streak Converters/Cameras I
Recent research and development in electron image tubes/cameras/systems
Show abstract
Recent results in development of the principal components of picosecond image converter recording systems are reviewed focusing on image tubes, streak and framing cameras, and CCD readout devices. Attention is also given to new laser sources capable of generating very stable femtosecond and picosecond optical pulses for dynamic calibration of image tubes and cameras and application of the designed instruments in laser research.
Poster Session
Circular encoding in large-area multiexposure holography
R. Aliaga,
Peter Choi,
Hernan H. Chuaqui
Show abstract
A novel method for encoding large number of large area holograms on the same
recording surface using a multi-.exposure scheme is presented. The separation between
each individual hologram is achieved by keeping constant the angle of incidence between
the object and reference beams, while the azimuthal angle of the plane that contains both
beams is changed between successive exposures. The reconstructed image is thus arranged
along the arc of a circle. Art image-plane configuration is used to record the hologram.
The resulting focal spot of the real image in the reconstruction allows each image to be
easily separated with a suitable aperture even at high encoding density. The problems
associated with the multi-exposure holographic technique, such as limited exposure
latitude and low signal to noise ratio, were reduced using a solution physical developer,
CPA-i, with standard holographic plates. More than 200 individual holograms were
recorded on one single plate with the upper limit possible measured to exceed 1000.
Gatable photonic detector and its image processing
Hidehiro Kume,
Haruhito Nakamura,
Makoto Suzuki
Show abstract
With the recent demand for high-speed imaging at ultra-low light levels, high-speed
electronic shutter cameras using gatable image intensifiers have been developed and used
for various ultralow light measurements. This paper provides some of the latest
developement on high-speed electronic shutter cameras using high-speed gatable proximity focused
image intensifiers.
By applying special treatment in fabricating photocathodes of proximity-focused image
intensifiers, we could gate it at the rise and fall times of 2 ns. As one of the compact &
versati le readout camera us ing gated image intens ifiers, ICCD camera and an image sampling
unit have been developed for compact shutter camera, low light detector and image sampling
processing use. For detecting of very weak light, the image intensifier with 2 NCPs and
booster image converter were developed to detect down to the single photon state with a
gate function included.
These devices and a new image readout technic developed lately will be discussed in this
paper.
High-speed still video photography for ballistic range applications
Brian A. Speyer
Show abstract
A new High Speed Still Video (SV) caera system has been developed by Hadland Photonics Limited (U.K.)' specifically to address the problem of recording projectiles in flight and other associated ballistic events. The system, known as the SV-553 BR. camera, is capable of capturing fast moving events with exposure times selectable from 1 millisecond down to 200 nanoseconds and displaying the captured image on a high resolution monitor within 0.5 second of triggering the camera. This paper describes the design of the system and gives examples of a variety of events recorded with the camera.
Visualization and Applications V
Focusing of shock waves in water and its observation by the schlieren method
Kohji Isuzugawa,
Michio Horiuchi,
Yoshiyuki Okumura
Show abstract
A spherical shock wave is generated by one spark discharge between electrodes at the first focal point of a rotationally symmetrical semiellipsoid, a part of the spherical wave reflects from the semiellipsoid, and produces a high pressure near the second focal point. This characteristic is used for the extracorporeal shock wave lithotriptor. However, there are some points to be made clear, such as the mechanism of shock wave generation and the process of its reflection and focusing. In this study, as the first step, visualizing the behavior of the shock wave is tried by means of the schlieren system using an iris instead of the knife edge. Especially in order to make the aspect of reflection clear, cylindrical shock waves generated by underwater wire explosions are used with an elliptical reflector. Photographs are taken with the image converter camera 'IMACON 790', and as the result the whole process from the generation to the focusing of the shock wave is clearly shown.
Conversion of schlieren systems to high-speed interferometers
Roland C. Anderson,
James E. Milton
Show abstract
Methods of converting schlieren systems into interferometers for high speed applications have been studied both theoretically and experimentally. Theoretical analyses include dark central ground, field absorption (also called point diffraction), and phase contrast interferometers. Experimentally, dark central ground and field absorption has been used in a 45 cm diameter double pass schlieren to produce infinite fringe interferograms of projectiles flying at approximately 1600 m/s. The latter was done in the Aeroballistics Research Facility, Eglin AFB without special attention being given to vibration or to temperature changes. Some possible vibration effects are discussed.
Picosecond and Femtosecond Techniques
Picosecond x-ray streak camera improvement
Xun Hou,
XiaoQiu Zhang,
Maixia Gong,
et al.
Show abstract
A development status evaluation is presented for a picosec soft X-ray streak camera whose initial two-window readout system has been replaced by a 512 x 512 x 4 computer image processor. In addition, a turbomolecular vacuum pump has been used in place of an ion pump. This streak camera has been used in both high power laser and optical physics research.
High Speed Video Techniques
High-speed readout CCDs
Show abstract
Limitations of standard three-phase frame transfer CCDs in high-speed operation are discussed with particular attention given to parallel and serial transfer, and the output amplifier. It is noted that in most CCD designs the greatest limitation on high-speed performance occurs in a serial register. At very high clock frequencies (greater than 30 MHz) actual generation and transmission of the necessary pulses can become the dominant restriction. Multiple output registers make it possible to obtain much higher readout frequencies. Design of a high-speed device capable of being fully readout in less than 2 mS is presented.
Poster Session
Stereoscopic holographic cinematography
Felix Albe,
Paul Smigielski
Show abstract
Multiplex holograms makes it possible to record moving objects with very low velocity. To palliate this disadvantage a new method is proposed. Each picture of the film is a one-step rainbow holographic stereogram recorded from two or more stereoscopic slides of computerized pictures. A CW Ar(+) laser and a 35 mm Holotest 8E56 film are used. The experimental set-up and some photographs of a holographic film are presented.
Holography and Interferometry VI
Interactions of laser-induced cavitation bubbles with a rigid boundary
Barry Ward,
David C. Emmony
Show abstract
Although the dynamics of cavitation bubbles near rigid boundaries have been
widely studied using conventional high-speed photographic and schlieren
techniques, no quantitative optical measurements of the pressure changes which
arise within the liquid and solid media have previously been reported. In this
paper, we present a series of high-speed Mach-Zehnder video interferograms of
a Nd:YAG laser-induced cavity in water at a distance of 2.7 mm from a plane
PMMA boundary. During the first cycle of oscillation, a maximum cavity radius
of 1 mm is attained and a translational motion towards the solid wall is
observed during which three complete radial oscillations occur. The
asymmetrical build-up of pressure in the surrounding liquid during bubble
collapse and the subsequent emission of spherical acoustic transients with
peak pressures in the order of 100 bars are related to the initial cavity
position and size. By viewing the propagation of these acoustic waves across
the rigid boundary and into the PMMA, direct measurements of peak stresses in
the bulk solid are made.
High Speed Video Techniques
Application of one-dimensional high-speed video camera system to motion analysis
Naoki Yokoyama,
Tsuneyoshi Uyemura
Show abstract
This paper describes application of versatile one-dimensional high-speed video
camera system to motion analysis. This system consists of linear-image sensor, frame
memory and personal computer. This linear-image sensor scans object image onedimensionally
at the rate of 2 MHz(maximum), and outputs analog signal to the
interface between this sensor and the frame memory.The interface then adds
horizontal and vertical synchronization signals to simulate NTSC-like composite video
signal at the lower sampling rate for frame memory. This frame memory has
resolutions of 5 1 2(H)X5 1 2(V)X25 6(I) and reconstructs 5 1 2 dots' intensity distribution
into a line, then 480 line images become a full two-dimensional image on framememory.
At the maximum speed, sampling clock is 2.048 MHz, so shortest sampling
period between line-scannings is 250 micro seconds. This is not so high speed
compared with traditional streak cameras. But resultant images can be digitized and
stored in the memory. Therefore various image-analysis and motion analysis can be
performed with personal computer.
Experiments were performed to test this video-recording camera. The object was
movement of Z-axis linear stage driven by stepping motor (1 micro meter/pulse),
which is totally controlled by host computer. The video-camera was operated at 512
KHz to 2.048 MHz. The resultant trajectory stored on frame-memory was timedisplacement
characteristic of object. Because no moving part is included in this
camera, synchronization between camera and object can be done in microseconds
precision. And recording speed of the camera system can be switched in every horizontal
scan. So object's displacement in one scan can be adjusted to be about pixel separation
of the image sensor, therefore quantum error due to spatial digitization can be
SPIE Vol. 1358 19th International Congress on High-Speed Photography and Photon/cs (1990) / 351
minimized. In addition experimental results can be observed and analyzed immediately
after recording.
Visualization and Applications III
High-speed photography of high-resolution moire patterns
Show abstract
The techniques of high resolution moire photography and high speed photography have been combined to allow measurement
of the in-plane components of a transient displacement field with microsecond time resolution. Specimen gratings are
prepared as casts in a thin layer of epoxy resin on the surface of a specimen. These are illuminated with a flash tube and
imaged onto a reference grating with a specially modified camera lens, which incorporates a slotted mask in the aperture
plane. For specimen gratings of 75 lines mm1, this selects the +1 and -1 order diffracted beams, thus doubling the effective
grating frequency to 150 lines mm1. The resulting real-time moire fringes are recorded with a Hadland 792 image converter
camera (Imacon) at an inter-frame time of 2-5ts. The images are digitised and an automatic fringe analysis technique based
on the 2-D Fourier transform method is used to extract the displacement information. The technique is illustrated by the
results of an investigation into the transient deformation of composite disc specimens, impacted with rectangular metal
sliders fired from a gas gun.
Holography and Interferometry I
Holographic visualization of hypervelocity explosive events
I. C. Cullis,
Richard Jonathan Parker,
Derek Sewell
Show abstract
A pulsed ruby laser and specially constructed 'holocamera' were used
to produce three-dimensional, holographic images of explosively
formed hypervelocity projectiles in flight. Velocities of the
projectiles studied were up to 6,500m/s. Using this holographic
technique it was possible to study interaction of these projectiles
with solid targets and even the effects of detonation under water. The
hologram proved particularly useful in the study of jets of low
density materials which were transparent to X-ray techniques.
Opto-Mechanical Cameras and Systems I
Use of high-speed photography in the evaluation of polymer materials
John P. Dear
Show abstract
Three photographic studies are presented which capture the behaviour of material specimens as they
are taken to and beyond their failure point by impact and other loading conditions. One is of a polymer
sphere impacting onto a rigid flat surface and depending upon the impact velocity, the sphere can fail in
different ways. The next study considers the propagation of a failure crack across the boundary of two
bonded materials of different toughness. Streak photography is used to capture the change of crack
velocity at the interface and other information. The final study relates to a free-flight striker impacting onto
a rectangular sheet of polyethylene supported at its four corners. Above a given velocity, the striker will
punch through the sheet but at impact velocities below thi s, there are several possibilities and some of
these are examined.
Image and Data Processing
Human movement analysis with image processing in real time
Show abstract
In the field of the human sciences, a lot of
applications needs to know the kinematic
characteristics of the human movements
Psycology is associating the characteristics
with the control mechanism, sport and
biomechariics are associating them with the
performance of the sportman or of the patient.
So the trainers or the doctors can correct the
gesture of the subject to obtain a better
performance if he knows the motion properties.
Roherton's studies show the children motion
evolution2 . Several investigations methods are
able to measure the human movement
But now most of the studies are based on image
processing. Often the systems are working at the
T.V. standard (50 frame per secund ). they
permit only to study very slow gesture. A human
operator analyses the digitizing sequence of the
film manually giving a very expensive,
especially long and unprecise operation.
On these different grounds many human movement
analysis systems were implemented. They consist
of:
- markers which are fixed to the anatomical
interesting points on the subject in motion,
- Image compression which is the art to coding
picture data. Generally the compression Is
limited to the centroid coordinates calculation
tor each marker.
These systems differ from one other in image
acquisition and markers detection.
Holography and Interferometry II
Three-dimensional shape restoration using virtual grating phase detection from deformed grating
Shaoxiang Zhou,
Jinyou Jiang,
Qimin Wang
Show abstract
A quasi-real-time phase detection method for restoring three-dimentional profile is proposed based on
phase shifting technique. A deformed grating is formed on the surface of an object under test with the aid of
projecting a Ronchi grating. The phase distribution of the deformed fringes corresponds to the profile of the objct.
Four scanning moire patterns, having phase difference of itI 2 successively, are generated by means of a virtual
grating shifting. The phase values are available at every pixel location from the deformed grating. The principle
ofthe method and some experimental results are presented in this paper.
Visualization and Applications I
High-speed photography at the Cavendish Laboratory
John E. Field
Show abstract
Both framing and streak photography techniques have intensive development histories at the Cavendish Laboratory of Cambridge University. These have been applied to the fracture of materials, ballistic impact phenomena, rain and particle erosion processes, explosive initiation and propagation, the interaction of acoustic waves with cavities, and various fluid-mechanics problems. Illustrative cases of moire and laser speckle photography are presented.
Framing/Streak Converters/Cameras II
New framing image tube with high-spatial-resolution
Chungu Zenghu,
Xun Hou,
Yongfeng Zhang,
et al.
Show abstract
An image conversion tube designed for framing photography with nanosecond/microsecond exposure time is described. High dynamic spatial resolution is obtained by gating electron beam after deflecting it in the tube. Electron optics computer simulation shows that 30 lp/mm can be resolved within 22 mm cathode.
Framing/Streak Cameras Converters/Cameras III
Development of picosecond x-ray framing camera
Chungu Zenghu,
Xun Hou,
XiaoQiu Zhang,
et al.
Show abstract
X-ray picosecond framing photography using optical framing and
deflection shuttering has been proposed and demonstrated in our
laboratory for several years. Four frame dynamic images have been
obtained with l7Opsec exposure time. The recent modification and
developments of the image tube and camera are described.
The aim of our modification is to decrease the exposure time and
improve the dynamic spatial resolution. Resolution of 5 lp/mm has
obtained.
To dynamically test the frasming camera which uses demountable
image tube, a mode locked Nd: YAG laser system with two stage second
harmonic generator has been built. Secondary electron emission has
been used to imitate the X-ray photoemission in the testing of
framing camera.
Holography and Interferometry II
Active mode-locking of external cavity semiconductor laser with 1GHz repetition rate
Xianhua Wang,
Guofu Chen,
De-Sen Liu,
et al.
Show abstract
This paper discusses active mode-locking technique of semiconductor lasers at a
repetition rate of 1GHz.In this work , we use microstrip line matching circuit which
is especially designed to match impedances between an ultrahigh frequency source
and a laser diode . The laser diodes used in our experiments have antireflection
(AR) coatings on one facet . The /4 SlO AR coatings greatly reduce the etalon
effects from the laser diode subcavlty . The reflectivity of one facet of lasers
has less than 0.2 % . Operating characteristics of laser diodes are also described
in this paper
Opto-Mechanical Cameras and Systems I
Laser optical fiber high-speed camera
Sheng-jie Xia,
Ye-min Yang,
Di-zhu Tang
Show abstract
An optical fiber transformer as an optical shutter and a light source divider both, a shadowgraphic set as an image system and
a polygonal cone as an image divider are employed to form a camera for high speed photography. One end of the fiber
transformer is arranged in a row and other end is in a circle, and by means of a small high sensitive optical scanner, a laser
beam is swept from one end to the other end of this row and flashed on the circle. A high speed shadowgraphic camera with
multi-point light source rounded within 1 0mm in dia. is obtained. The framing rate will be 1 o6 pp or more and the exposure time
of each frame will be O.8jts or less if an 1 KHz scanner is used. Sixteen shadowgrams can be obtained at a time. The distance
between any two fibers can be adjusted individually to get the records with nonequal time interval to match the event under
study. The high speed interferography will be made if the single mode fibers are used. The framing rate can also be increased
by use of a faster scanner and a more power laser.
Poster Session
Application of high-speed photography in the design of new initiating systems
Ann F. Steele
Show abstract
A detailed study of the detonation characteristics of initiating systems
can be made using the well known "Aquarium Technique". High speed
photography, in conjunction with computer simulation, help to set out the
limits of initiating systems design criteria.
The poster will present
a) How high speed photography and computer predicted simulation work
together - from fundamental experiments to new product design, and
b) The benefits of this two-fold approach to primer design.
Laser and Light Sources I
Inspection system using still vision for a rotating laser-textured dull roll
Akira Torao,
Hiroyuki Uchida,
Susumu Moriya,
et al.
Show abstract
A new inspection system measuring micro-craters on a rotating laser textured
dull roll surface has been developed. This system provides a video image of the
rotating roll surface as a still vision using a stroboscopic light and a rotating
mirror, and measures the diameter and the pitch of the micro-craters by an image
processing method. The system can measure the pitch and the diameter of the
micro-craters in the accuracy within ±10 mm errors when the circumferential speed of
the dull roll is lOm/sec.
High Speed Video Techniques
Techniques for capturing over 10,000 images/second with intensified imagers
Kris S. Balch
Show abstract
A motion analyzer is used to capture images from a high speed video camera and store the images in real-time for
review. The more sophisticated motion analyzers have the capability to split the field of view with two cameras. Furthermore,
these cameras, also known as imagers, can be intensified. Intensification of the imager with hybrid technology
will amplify the light and electronically shutter the action. By controlling the intensified imager's electronic
shutter and using multiple intensified imagers, over 10,000 partial frames per second (pfps) can be captured and
stored. Once stored, the images may be reviewed in slow motion while quantitative measurements can be made for
analysis. Motion analyzers are powerful tools for industry and science in viewing high-speed events. In this application
an event would be a high velocity object moving in a horizontal plane to the two imagers. The high sample rate
is accomplished with a motion analyzer capable of split field of view and intensified imagers with a controllable shutter
This paper will describe several motion analyzer techniques for capturing above 10,000 pfps including intensifier and
motion analyzer technology.
Laser and Light Sources I
New generation of copper vapor lasers for high-speed photography
Brian T. Walder
Show abstract
Copper vapor lasers (CVLs) have been used in high-speed photography and flow visualization to study spray droplets, projectiles, turbines, and textiles. Attention is presently given to a new design generation of CVLs which offer 25-35 nanosec pulse width, single/multiple flash, fiber-optic delivery of light, automatic synchronization, operation from single phase, and up to 32 kHz repetition frequency. An account is given of the results of illustrative applications of these CVLs.
Poster Session
Laser generation of Stoneley waves at liquid-solid boundaries
Barry Ward,
David C. Emmony
Show abstract
High-power laser radiation has long been used as a source of plasma-generated
bulk and surface waves in solids. Of particular interest in this field are
Stoneley waves which propagate at the plane boundary between two semi-infinite
condensed media. In this work, the near-infrared radiation from a 1O-mJ
Q-switched Nd:YAG laser is focused at water-metal, water-PMMA and water-glass
interfaces. Ultra-high-speed dye-laser photography is used to visualise the
propagation and attenuation of Stoneley and bulk-compression waves in the
transparent media using Mach-Zehnder interferometry and focused shadowgraphy.
It is believed that these results represent the first direct observation of
Stoneley waves. By using Abel-inversion techniques, the pressure amplitudes in
the two media are found as functions of both space and time. This leads to an
understanding of the energy-dissipation processes which take place as the
waves propagate outwards.
Framing/Streak Converters/Cameras I
ULTRANAC: a new programmable image converter framing camera
Brian R.C. Garfield,
Mark J. Riches
Show abstract
The development of an image converter framing camera with the feasibility of operation at frame rates of up to 50 million frames per second is described. The camera incorporates a new 'grid' gated all metal/ceramic image converter tube which is manufactured 'in-house' by the vacuum transfer processing method. All solid state electronics are used to drive the image converter tube. Exposure and interframe times can be set individually to different times if required with these and other camera functions programmed and controlled via standard personal computer. Results obtained for the camera operating in its various modes are presented.
Framing/Streak Cameras Converters/Cameras III
Temporal and spectral analysis of the synchronization of synchroscan streak cameras
Bernard Cunin,
P. Geist,
Francine Heisel,
et al.
Show abstract
A stochastic model has been developed to explain the well-known experimental results in synchroscan measurements with actively mode-locked lasers demonstrating that in the configuration where the synchronization is carried out by means of the ultrastable oscillator exciting the acoustooptic mode-locker of the laser, the overall temporal resolution is considerably worse than in the case where the deflection is performed by the electric signal directly derived from the optical recurrent pulses. The calculations including both random period fluctuations of the laser pulses and temporal jitter due to the electronic trigger system are corroborated by experimental investigations. The study shows that even in the presence of the phase noise in the laser beam, a jitter free synchronization can be achieved.
Framing/Streak Camera-Applications
High-dynamic-range image readout system
Alain Mens,
N. Ducrocq,
E. Mazataud,
et al.
Show abstract
A new image readout system has been developed for the diagnostics of laser-matter interaction experiments. It has been
designed to work both as an X-ray detector (for X-ray optics or pinhole cameras) and as a streak readout system. We present
here the main features of the system, its performance, its advantages over our previous system and the results obtained in
experiments.
Picosecond and Femtosecond Techniques
Temporal fiducial for picosecond streak cameras in laser fusion experiments
Alain Mens,
Dominique Gontier,
P. Giraud,
et al.
Show abstract
A recording of temporal reference on picosecond streak camera images requires to transmit laser pulses of different
wavelengths through optical fibers (O.F.) onto streak cameras.
We describe the O.F. network installed on the PHEBUS laser to provide streak cameras and photomultipliers with a
200 ps pulse.
We also describe the tests performed on various fibers to evaluate their transmission (? = 0.35 tim) and on
photocathodes to get the best photons-electrons conversion efficiency in open X-rays tubes.
Then we describe the experimental test set up also installed to easily check the sweep linearity and speed and also the
amplitude response of X-rays cameras, using this fiducial system. We show practical results of those tests, and some laserplasma
interaction experimental results.
Framing/Streak Converters/Cameras I
C 850X picosecond high-resolution streak camera
Alain Mens,
J. M. Dalmasso,
Richard Sauneuf,
et al.
Show abstract
A new camera is described which is based on the P 850X bi-lamellar streak tube with separated focusing of the electron beam along the temporal and spatial axes. The camera is characterized by a spatial resolution of 16 lp/mm in dynamic mode and a temporal resolution from 2 to 3 ps. The digital control of the tube makes it possible to choose between several different operation modes.
Framing/Streak Converters/Cameras II
New streak tubes of the P500 series: features and experimental results
Jean-Claude Rebuffie,
Alain Mens
Show abstract
Philips streak tubes which are fabricated using the transfer technique which is considered to be an ultimate method for producing multialkali photocathodes are considered. Particular attention is given to the main steps of the S1 photocathode process setup, the photocathode sensitivities obtained on cells and streak tubes, the photocathode stability vs. time, and static and dynamic characteristics of the P 510 and P 520 streak tubes. It is concluded that the general performance of the P 500 streak tubes is appropriate for applications in molecular physics, detonics and ballistics, velocity measurements based on Doppler laser interferometry, electrical discharge research, and fiber optic communications.
Visualization and Applications IV
High-speed time-resolved holographic interferometer using solid state shutters
Show abstract
The high speed recording of shock waves is presently undertaken by a solid-state, time-resolved holographic interferometer in which spatial frequency multiplexing is used to separate the holographically recorded images. The reference beam is constantly divided into n branches of equal brightness by a stack of suitably graded beam splitters, so that each branch is aimed at the film from a different angle and individually shuttered by an electrooptic light valve. This arrangement allows complete freedom to have any or all of the reference beams reach the film for a given pulse of the laser. The implications of these capabilities for shock-tube studies are explored.
Framing/Streak Converters/Cameras IV
Peculiarities of frame memory design for slow-scan readout system for scientific application
Mikhail V. Vyssogorets,
Natalya N. Mitrofanova,
Mikhail Yu. Petrov,
et al.
Show abstract
The image readout and image processing in high speed phenomena, like electron—optical camera and pulse lasers application have some specific requirements: a high dynamic range for the total electron—optical readout system ( about 1000) , an ability to capture a number of pulse images in one laser shot. For scientific applications it is also desirable to develop software for each specific task with wide range of software development systems, compilers, libraries thus reducing development time whereas it is not required a real time image processing with the rate of 40 ms/frame. The described system is intended for such applications.
Opto-Mechanical Cameras and Systems II
Hubble Space Telescope: mission, history, and systems
Show abstract
Evolution of the Hubble Space Telescope (HST), an astronomical observatory orbiting the earth 380 miles above its surface is considered. The equipment onboard this satellite includes a telescope with a 96 inch primary mirror ground, a wide field and planetary camera, a faint object spectrograph, a Goddard high-resolution spectrograph, a high-speed photometer, and a faint object camera.
Gated Intensifiers
Advanced image intensifier systems for low-light high-speed imaging
Show abstract
An extensive research program has been conducted to characterize the performance of image-tube components under conditions typical of adaptive optics systems, as well as to develop novel image-tube components and assembly techniques. A comparison is presented of standard image-tube capabilities which identifies the tube components which fall short of requirements. Attention is given to the fiber-optic faceplate, phosphor formulation, gate-electrode pulsers, power supplies, and intensifier packaging that have been developed.
Image and Data Processing
Multiple-channel correlated double sampling amplifier hybrid to support a 64 parallel output CCD array
Chris A. Raanes,
John A. McNeill,
Andrew P. Cunningham
Show abstract
A correlated double sampling hybrid amplifier is developed to support a parallel output, high frame rate CCD camera. The hybrid amplifier is capable of supporting less than 100 electron rms system noise at a frame rate of 5 kHZ even with the low input conversion efficiency. The output from the hybrid is either a high speed multiplexed analog signal (up to 8 MHz) or 4 nonmultiplexed channels. It is easily adaptable to most CCDs.
Opto-Mechanical Cameras and Systems II
Auto-focus video camera system with bag-type lens
Norio Sugiura,
Shinzo Morita
Show abstract
An auto focus video camera system using a bagtype lens was
developed. The bagtype lens was formed by pasting two plastic films on
a ling spacer and by filling with liquid. Its focus could be
controlled quite freely by changing the volume of liquid filled. Focus
control signal was obtained by differentiating the CCD video signal. A
simple object was brought into the focus automatically within about 20
seconds in this system.
Visualization and Applications IV
Laser light sheet investigation into transonic external aerodynamics
Show abstract
The present light sheet system for 3D studies of the location and structure of transonic flows employs a CCD video camera and digital frame-store which are synchronized with the pulsed laser so that the resulting images can be immediately displayed via microcomputer. These video images are digitally enhanced in order to display 3D coordinate data. An illustrative demonstration of the system is for rotating transonic-jet flow. The visualized images show instantaneous transonic flow structures.
Poster Session
Holographic interferometric observation of shock wave focusing to extracorporeal shock wave lithotripsy
Show abstract
Underwater shock wave focusing is successfully applied to disintegrate and remove kidney stones or
gallbladder stones without using surgical operations. This treatment is one of the most peaceful applications
ofshock waves and is named as the Extracorporeal Shock Wave Lithotripsy. Ajoint research project is going
on between the Institute ofFluid Science, Tohoku University and the School ofMedicine, Tohoku University.
The paper describes a result of the fundamental research on the underwater shock wave focusing applied to
the ESWL. Quantitatively to visualize the underwater shock waves, various optical flow visualization
techniques were successfully used such as holographic interferometry, and shadowgraphs combined with
Ima-Con high speed camera. Double exposure holographic interferometric observation revealed the
mechanism of generation, propagation and focusing of underwater shock waves. The result of the present
research was already used to manufacture a prototype machine and it has already been applied successfully
to ESWL crinical treatments. However, despite of success in the clinical treatments, important fundamental
questions still remain unsolved, i.e., effects of underwater shock wave focusing on tissue damage during the
treatment.
Model experiments were conducted to clarify mechanism of the tissue damage associated with the ESWL.
Shock-bubble interactions were found responsible to the tissue damage during the ESWL treatment. In order
to interprete experimental findings and to predict shock wave behavior and high pressures, a numerical
simulation was carried. The numerical results agreed with the experiments.
Appreciation of the Society of Motion Picture and Television Engineers: the originators of the Congress
George H. Lunn
Show abstract
It seems that many people contributed to the invention of the motion picture
systems. In USA, it seems that Thomas A Edison (1847-1931) or his company did much
of the practical work, initially proposing the Film principle.
The cine-camera was achieved in a number of ways, mainly because the exposure
can be a small portion of the interval between frames, BUT in the projection period,
the film must be halted to give a good screen image for a large portion of the total
interval. This is the point which Charles Francis Jenkins (1867-1934) says he saw
first and proposed a "beater" to drive the film forward which became through Thomas
Armat (1866-1948) the Geneva Cross Drive. Thus the final step was the combination of
all three inventors with Edison and George Eastman (1854-1932) providing the
continuous film and the Camera and the Projector, first demonstrated by Jenkins
(early 1895) improved by Armat and made by Edison as the Vitascope.
Laser and Light Sources I
New rippleflash system for large-area high-intensity lighting in harsh environments
John T. Rendell
Show abstract
Early in 1985, Bowen Electronics Ltd., introduced their now well known Rippleflash
High Intensity Lighting system using the 5 + 5 flashbar expendable flashbulbts
universally used in amateur Polaroid cameras.
The decision to use these miniatures was taken as a result of the uncertainty of
future supplies of the conventional large Types 2, 3 and FF30 flashbulbs
manufactured by Sylvania USA. Ten years earlier, other manufacturers had
ceased production of the large ES bulbs due to the decline in consumption by
industrial and commercial photographers, following the introduction of powerful new
electronic flash sources.
Framing/Streak Camera-Applications
Use of an image converter camera for analysis of ballistic resistance of lightweight armor materials
J. L.M.J. van Bree,
E. J.M. van Riet
Show abstract
Experiments to measure the ballistic resistance of light weight armour materials normally comprise the determination of the
ballistic limit velocity V50 for a standardized fragment simulating projectile.
However, in order to characterize these materials in more detail, it is of great interest to know the dynamic response of armour
materials at impact.
To this end, high speed photography is used to monitor target behaviour during impact and subsequent perforation in a timeresolved
manner.
Moreover, in the field of personal protection it is of importance to know the maximum temporary indentation for nonpenetrating
projectiles at impact velocities near the critical V50 velocity as a parameter for trauma-effect.
Experiments, making use of a Imacon camera, are described in which materials for light weight armour applications were
screened.
Visualization and Applications IV
Breakdown in pulsed-power semiconductor switches
Show abstract
A model for the high voltage breakdown of semiconductors is
developed which can be applied to new high power switches, which were
presented on the 18th ICHSPP, or to well known Zener diodes. Computer
calculations show that a breakdown may result in localiced current
streams. The distribution of the current is inhomogenious in general.
The current distribution may show periodicity in space and in time,
similar to sawtOoth oscillations with a constant frequency. This
frequency can be varied by external parameters. Or it may be chaotic,
then a broad frequency spectrum is produced.
High Speed Video Techniques
High-speed CCD video camera
Show abstract
A High-Speed CCD-TV-camera is demonstrated with a frame rate up to
30 kHz. The horizontal resolution is 600 pixels. The vertical
resolution depens on the number of pictures in a high-speed sequence.
It varies from 288 lines for two pictures up to 20 for 28 pictures in
a sequence.
Visualization and Applications V
High-speed photography applied for the investigation of the dynamics of free falling evaporating droplets
L. P. Guryashkin,
Albert L. Stasenko
Show abstract
Three methods to investigate dynamics and heat and mass transfer of nitrogen droplet moving in the air are described. Drag coefficient and Nusselt number as functions of Reynolds number and of temperature values of a droplet and surrounding gas are derived.
Framing/Streak Converters/Cameras I
Theoretical and experimental performance evaluations of Picoframe framing cameras
Yueping Liu,
Wilson Sibbett,
David R. Walker
Show abstract
The dynamic performance of Picoframe I, II type framing cameras in both single-frame and double-frame operation have
been evaluated theoretically and compared with the corresponding experimental observations. Relevant methods of
theoretical computationally-based simulations are reviewed where predictions relating to image position, magnification,
spatial and temporal modulation transfer functions and photoelectron transmission through the apertures are provided. From
the simulations of photoelectron trajectories in the entire image tube during the framing operation it can be readily deduced
that the electron-optical focusing characteristics are influenced significantly by the dynamic fringe-field effects at the
deflectors. This is shown to be a major factor in determining the limiting dynamic spatial resolutions and frame times for
these particular designs of framing camera. Possible methods for compensating or alleviating this deficiency have been
outlined and some preliminary experimental confirmation has been included. Particular emphasis is directed towards
Picoframe cameras having ultraviolet and x-ray spectral sensitivities.
Framing/Streak Converters/Cameras II
Profile-related time resolution for a femtosecond streak tube
Yueping Liu,
Wilson Sibbett
Show abstract
The temporal performance of a streak image tube has been evaluated through a wide-ranging investigation of its temporal response characteristics for various input optical profiles. The concept of a profile-related resolution characteristic is presented which implies that the temporal structure of the input signals can be resolved with proper fidelity. The profile-related temporal resolution has been predicted to be approximately 1 ps for a streak tube that has a limiting time resolution of 250 fs.
High Speed Video Techniques
Discrimination and classification with Xybion multispectral video systems
Paul A. Frost
Show abstract
A multispectral imaging and analysis system has been developed for sophisticated applications in airborne remote-sensing and laboratory research. The system combines a high-speed multispectral video camera with an IBM-PC-compatible computer system. It is capable of great flexibility in multispectral measurement, detection, and classification applications. The camera design is based on a number of technologies which include low-light-level imaging, high-speed electronic gating, solid state CCD video, and miniaturized microprocessor control.
Laser and Light Sources I
High-speed microcinematography of aerosols
Stephen P. Lavelle,
Louise A. Jackman,
P. F. Nolan
Show abstract
Many existing techniques for aerosol characterisation are based on the utilisation of their optical properties, but have
a major disadvantage in so far as the results tend to be dependent on the signal processing techniques employed. A direct
measurement technique has many advantages particularly in terms of ease of validation and verification of results. An
innovative method for the characterisation of aerosols has been developed using a synchronised metal vapour laser light
source and a High speed cine camera. The use of an optical fibre and flexible borescope enables the image capture of
aerosols generated in a number of environments. Data has been collected in the form of size distribution, velocity and
trajectory. Data on collisions has also been collected.
Example studies have included the bio-hazard aerosols generated during industrial processing and the aerosol generated
from a two phase release of liquid petroleum gas.
Characteristics of sprinklers and water spray mists for fire safety
Louise A. Jackman,
Stephen P. Lavelle,
P. F. Nolan
Show abstract
In order to predict the type of sprinkler or spray head required for fire safety in buildings and transport systems
(e.g. aircraft) it is necessary to model the interaction of water droplets with the thermally buoyant fire gases. Such
modelling requires a detailed knowledge of the mean droplet size, the droplet size distribution, droplet velocity and
trajectory.
Many existing systems for the characterisation of droplets are indirect in that an optical property is measured and
the results are subject to "black box" data processing. A direct method can be developed using a synchronised metal
vapour laser and high speed cine camera with appropriate optics. Results on both sprinkler and spray mist will be
presented and a basis for the choice of active fire protection systems will be outlined.
Poster Session
Possibility of keeping color picture in an image converter camera
Zongyao Zhao
Show abstract
This paper d.eals with an important principle of keeping color picture in a system
of the image converter camera. With the help of a special color striped. filter, the
image in the optical system is modulated and. formed. a blackwhite striped. picture
on the fluorescent screen of the image converter tube. The color information of the
picture is contained in black-.white striped.. Then, the colored. picture will be res
tored after demothilating the blackvrhite stripes
Picosecond and Femtosecond Techniques
Stable picosecond solid state YA103:Nd3+ laser for streak cameras dynamic evaluation
A. V. Babushkin
Show abstract
A specially developed solid-state laser intended for dynamic calibration of
various type streak cameras is preseited. 5±lps light pulses of 0.5% output energy
instability were emitted by YA1O3:Nd crystal laser with hybrid mode-locking and
passive intracavity negajive feedback produced by the action of a GaAs plate.
After compression of single pulse inside the fiber optics compressor, the minimum
available pulse duration approaches O.3±O.lps. Such ultrashort pulses were
utilized for streak cameras dynamic parameters evaluation.
Framing/Streak Cameras Converters/Cameras III
328 MHz synchroscan streak camera
Show abstract
A high-frequency synchroscan streak camera based on the PV-006A tube and intended for operation with actively mode-locked sources is presented focusing on possibilities of increasing the streak frequency. In the proposed camera the deflection plates serve as a capacitive element of the cavity, thus providing all the RF power to be localized inside this cavity. An electrical shutter and image intensifier are used to select the recording time from 100 ns to 1 ms. At the input of the RF streak circuitry, a tunnel-diode oscillator is used which is based on subharmonic synchronization by the photodiode signal. Test results show that a temporal resolution of about 5 ps in CW mode can be achieved with a 375 Rh6G dye laser.
Picosecond and Femtosecond Techniques
Two-frequency picosecond laser with electro-optical feedback
Show abstract
A laser generating sinusoidally modulated radiation with stable and
reliable output parameters was created. As a basis for such a sourse the twofrequency,
pulse Nd-glass laser was chosen. In order to stabilize its output
parameters the cross positive electro-optical feedback was used. Such feedback
has provided Q-switched operation and simultaneos generation of two axial modes.
The modulation depth of output laser radiation is equal to 100%, but the
modulation period can be quasi-smoothly tuned from shot to shot within 6.6ns -
300fs time range.
Framing/Streak Converters/Cameras II
Improved version of the PIF01 streak image tube
Show abstract
The revised version of the PIFO1 image tube was computer-simulated,
designed and manufactured. For dynamic measurements of this tube, two laser
systems were employed: YA1O3:Nd solid state laser with fibre optics compressor
generating a 200 ns train of single pulses of 0.3 Ps pulse duration at
1.08 ,im wavelength, as well as two-modes Nd:glass laser generating sinusoidallymodulated
radiation with variable picosecond modulation period at 1.06 im
wavelength. Time-dispersed pictures from the PIFO1 phosphor screen were recorded
by SIT-vidicon readout system through crossover 1ype microchannel intensifier.
Temporal resolution of 1.3 Ps was measured at 10 cm/s streak speed and dynamic
range of better than 30. The PIFO1 tube spatial resolution was 25 line pairs/mm
over 6 mm input photocathode area, and its electron-optical magnification
was 1.5x. Comparative technical parameters of PIFO1 and PVOO1 will be presented, as
well as parameters of an experimental streak camera prototype built around PIFO1
image tube.
Framing/Streak Camera-Applications
Application of electron-sensitive CCD for taking off the time-dispersed pictures from image tube phosphor screens
Show abstract
Possibilities of EB CCD sensors application for electron-optical picosecond
recording systems have been investigated. Some requirements for the EB CCD
fabrication procedure were theoretically established and experimentally confirmed. EB
CCD sensors were inserted either into the first generation image intensifiers coupled
through fibre optics plate to the output of the temporal analysing tube or directly
instead of the phosphor screen of this analyser. In the second case the system
spatial resolution is slightly better while the sensitivity for both systems is
almost the same.
Picosecond and Femtosecond Techniques
Ultrafast streak camera evaluations of phase noise from an actively stabilized colliding-pulse-mode-locked ring dye laser
David R. Walker,
William E. Sleat,
J. M. Evans,
et al.
Show abstract
Modelocked laser systems are now capable of generating picosecond and femtosecond optical pulses
either directly or by employing optical pulse compression techniques. It has recently become
important in certain experiments that the repetition rate of the probe laser be precisely synchronised
with a radio-frequency drive signal, or with other modelocked laser systems. Examples of relevant
applications include those requiring sampling procedures (eg. electro-optic sampling) and also those
where synchronously-operating streak cameras are used. In the latter, long-term pulse-timing jitter
gives rise to an overall loss of camera resolution. Although the dispersion-compensated Colliding-
Pulse-Modelocked (CPM) ring dye laser is routinely capable of directly generating optical pulses of
less then 50 fs [1] it has become clear that such passively modelocked systems can suffer from
severe medium and long term phase noise. Investigations of this phase-noise by measurements made
in the frequency and time domains will be described here.
Framing/Streak Converters/Cameras I
Soviet-American image converter cameras "PROSCHEN"
Dennis Briscoe,
Chinmaya A. Shrivastava,
Sidney J. Nebeker,
et al.
Show abstract
Single shot streak and synchroscan image converter cameras were designed and manufactured within the framework of the Proschen joint venture. These cameras are characterized by an experimental temporal resolution better than 1.7 ps at a streak speed 6 x 10 exp 9 cm/s and a 1.08 micron input radiation wavelength. The synchroscan camera is capable of providing the temporal resolution of about 5 ps in CW mode at a 328 MHz repetition rate. Test results reveal that both cameras provide reliable technical parameters and are easy to operate and handle. Applications include laser development and analysis, laser plasma research, solid state physics, optical communication measurements and analysis, time-resolved spectroscopy and nonlinear optics, and laser ranging and pollution control.
Multiframing image converter camera
H. N. Frontov,
Yury N. Serdyuchenko
Show abstract
In this paper we describe a multiframe camera based on PV-OOl image tube. This
tube is very convenient for obtaining short frame exposures due to availability of
high-frequency shutter system with the image shift compensation facility, as well as
with one pair of high-frequency deflection system.
The developed camera provides 164 million frames/s recording speed with minimum
time exposure of about 3ns. The frame number is controled between 6 and 16. Dynamic
spatial resolution is not less than 5 line pair/ mm.
Framing/Streak Camera-Applications
Picosecond techniques application for definition of nonuniform ingradients inside turbid medium
Show abstract
For identification of a phantom (hidden foreign object) inside turbid medium
with different optical properties the time of flight (TOF) technique was used.
Nd:YAG-laser (X1064nm) as a light source and a streak camera with ultimate
time resolution of l.5ps were employed. Analysis of laser light transmited through
an experimental medium (a 2mm metal strip located inside a diluted milk) was
perfomed with the help of this camera and read out system. Transmission profiles
have shown that contrast ratio depends on the object position and medium
concentration. Theoretical calculations made by Monte-Carlo simulation were in a
good agreement with the experimental results.
Gated Intensifiers
Multialkali photocathodes grown by molecular beam epitaxy technique
I. A. Dubovoi,
A. S. Chernikov,
Alexander M. Prokhorov,
et al.
Show abstract
A new technique of bialkali photocathodes growth by molecular beam epitaxy (MI3E)
has been developed. The photocathode film was deposited onto the substrate from
molecular beams produced by simultaneously operating molecular sources of Sb, Na and
K. Thus suggested procedure is noticeably differed from the classical one. Growth
rate was about 1 A/sec and complete cycle of photocathode fabrication was 15-20
minutes. A special ultra high vacuum (UHV) chamber for MBE of multialkali
photocathodes has been designed. The chamber is a part of UHV system consisting of an
analysis vessel supplied with Auger and ESCA electron spectrometer and low energy
electron diffractometer (LEED), the MBE chamber itself and a chamber for cold sealing
of photocathodes with device body through indium ring. The system gives a possibility
to carry out investigations of multialkali photocathode physics and to produce
commercial devices. Developed technique can be used for fabrication of vacuum devices
including streak tubes.
Visualization and Applications V
High-speed photographic study of a cavitation bubble
Wee King Soh
Show abstract
The main objective of this programme is to carry out a scale model study on the behaviour of a cavitation bubble
during its collapse phase as effected by various types of surfaces.
The cavitation test rig consists of a decompressed chamber which utilizes a spark discharge technique to generate a
vapour cavity in water. The technique involves local heating and vaporization of the liquid through application of a thermal
impulse. The evolution of the bubble is recorded by an NAC E-1O high speed cine-camera. The images captured by the
cine-photography are later digitized for computer analysis.
Results show that the characteristics of the surface influence the dynamics of the nearby cavitation bubble. The
measured time interval for the bubble to collapse indicates that the pulsation pressure generated by a cavitation bubble near a
compliant surface will be less than that near a rigid surface.
Visualization and Applications II
New approach to synchroballistic photography
Show abstract
A new type of synchro-ballistic camera is described which, it is believed, overcomes many
of the disadvantages of existing types of film cameras. Advantages include continuous access with
negligible film wastage, compactness, easy daylight loading and low electrical power requirements.
Holography and Interferometry II
Interferometry, streak photography, and stereo photography of laser-driven miniature flying plates
Show abstract
Optical diagnostics to evaluate the velocity, acceleration profiles, planarity, and integrity of miniature (≤5 μm thick x ≤600 μm diam) plates of aluminum and other metals will be reported. By correlating various optical techniques and collected data, a complete understanding of the flying plate can be determined. Velocity interferometer system for any reflector (VISAR), with ≤120 ps resolution per data point, is used to record plate acceleration and terminal velocity. Electronic-streak and pulsed-laser stereo photography can determine planarity and integrity. Flyer-plate performance data are related to the properties of the laser beam that accelerates the plate. Laser parameters, such as energy density, power density, and spatial profile, affect the flying-plate performance parameters, i.e., planarity, acceleration, and velocity. Flying-plate accelerations of ≥1010 G and terminal velocities of ≥6 mm/μs have been recorded, via a 10-ns-Nd:YAG laser pulse delivered to a tamped, 5-μm-aluminum plate.
Opto-Mechanical Cameras and Systems I
One-frame subnanosecond spectroscopy camera
E. G. Silkis,
Vitaliei Titov,
Gregory G. Feldman,
et al.
Show abstract
The recording of ultraweak spectra is presently undertaken by a high-speed multichannel-spectrum camera (HSMSC) with a subnanosec-range time resolution in its photon-counting mode. This HSMSC's photodetector is a one-frame streak tube equipped with a grid shutter which is connected via fiber-optic contact to a linear CCD. The grain furnished by the streak tube on the basis of a microchannel plate is sufficiently high for recording single photoelectron signals. The HSMSC is compact and easy to handle.
Opto-Mechanical Cameras and Systems II
Multichannel mirror systems for high-speed framing recording
Leonid S. Ushakov,
A. M. Ponomaryov,
Vladimir V. Trofimenko,
et al.
Show abstract
Two systems for providing simultaneous multi-streak records of a fast event are proposed. The first system is capable of producing 15 streaks of 2D images with image rotation from one channel to another and can be used in a chronotomographic installation. A series of successive 2D frames of the event are reconstructed using a tomographic reconstruction technique. The second system is capable of producing 15 simultaneous streaks of 1D slit images which are obtained by dissection of 2D image of the object. High framing rates can be achieved which approximate the inverse temporal resolution of a streak camera in both cases. The total number of more than 100 frames can be easily obtained with both techniques.
Super-high-speed reflex-type moving image camera
Yu. A. Drozhbin,
Vladimir V. Trofimenko
Show abstract
Experimental investigations ofthe spatial-time characteristics ofhigh-energy pulse lasers possessing
generation pulse duration ranging from tens of microseconds up to tens of nanoseconds and spectral
radiation band from vacuum ultra-violet up to infra-red (1O.6raLcr,m) are facifitated by use of
optical-mechanical instruments of high-speed photography that employ reflex-type optical systems.
High-speed ofthe mirror rotar rotation is obtained through utffization ofa turbine actuator on aerial
supports.
Ultrafast optical-mechanical camera
Yu. A. Drozhbin,
Vladimir V. Trofimenko,
T. I. Chernova
Show abstract
The ultrafast photo camera continues the development ofoptical-mechanical cameras with revolving
mirror and reflecting optical systems that can operate in a wide range of spectrum from ultra-violet
up to infra-red [1, 2]. The 3CctK-3 camera, unlike the previous ones, is not of a delaying type; it
operates in synchronism with a phenomenon under investigation. The 3CPK-3 camera is a twochannel
model. Its design ensures the recording of a process under investigation by each of the two
channels independently. The channels are spaced apart at a distance of 350 mm; it makes reason
in studying gas dynamic and hydrodynamic processes, for instance, in aviation and automobile
engineering. The camera can be used both for investigation of self-luminous processes and for
utilizing pulsed sources of illumination.
Framing/Streak Cameras Converters/Cameras III
Image converter streak cameras with super-light-speed scanning
V. I. Averin,
M. S. Gus'kova,
Irina M. Korzhenevich,
et al.
Show abstract
Streak cameras with superlight-speed scanning and technical time resolution greater than the real one are of great interest for investigation of the extreme possibilities of an image converter streak technique. Problems are reviewed which arose during the development of Agat-04M, Femtochrom, Positron, and Selena-2 cameras in the All-Union Research Institute for Optical and Physical Measurements, Moscow.
Framing/Streak Converters/Cameras IV
Modular equipment for single-frame photography in wide-time and spectral ranges
Show abstract
A set of modules has been designed, which incorporates six types of recorders on the basis of open
and closed (sealed off) ICT, electrooptical shutter and 4 types of control units, three of which are
generators of only pulsed voltages, while the fourth one is a constant and pulsed voltage generator.
By replacing recorders containing different types of closed ICT's, being flat or with a turn of the
image, or open flat lOT's with a MCP-cathode and different films (Au, CsJ, MgF2) on it (a modification
with two MCP's is also possible), it is possible to ensure the sensitivity ranging from the near infrared
radiation to hard X-ray one. The latter ICT's may be used as detectors of corpuscular fluxes, in
particular, ions in the Thomson's mass-spectrographs, as well. The replaceable control units ensure
the exposure duration range of 3 1Ob0 3 •
Picosecond and Femtosecond Techniques
Thomson parabolic spectrograph with microchannel plate framing camera as register of ionic parabolae
Show abstract
Thomson parabolic spectrograph (TPS) is a well known device, which is broadly used by researches
of energy spectrums of ionic components of plasma [1]. In the recent years this device induces a new
interest of researchers in connection, that for iones registration a micro-channel plate (MCP) [2-4]
is used now in this particular device. That measure increased up to several ranges sensibility of
registration in comparison with traditional photo film and, besides this fact, it permitted to strobe
TPS and research temporary evolution ofionic spectrum ofimpulse sources. Ion research in strongly
accurate electron beams at the expense of TPS has been conducted in Sukhumi physical-technical
institute [5]. Here as register was used one exposure camera "UNICADR-R" with MCP, size: 70 x
90 mm2 [6]; this camera has been worked out in YNIIOFI for registration of Roentgen spectrums.
The camera had a gain 1O. In this particular work are reported results of TPS researches, worked
out in VNIIOFI [7]. A special track of this device is the fact, that it possesses a deviating system of
registrating on basis of constantly operating magnets and regular registration system on basis of
amplifying section image converter tube (ICT) a PIM-104 [8]; its chevron MCP permits to receive
a gain 106. Tuning and calibration of device has been conducted at the expense of plasma accelerator
accessed with erosion electrode. Scheme of disposal for TPS research is shown on figure 1.
Framing/Streak Converters/Cameras IV
Examination of EOT operation with spherical elements or slit accelerating diaphragm
Show abstract
As it is known, the EOT's have a time C-shaped distortion resulting in a band of equal time lines
on the EOT screen. This distortion may be compensated for by an external optical system [1] or
eliminated with the aid of a spherical cathode and (or) accelerating grid [2, 3]. The designs of refs
[2, 3] were calculated by exhaustion ofdifferent cathode and grid radii ofcurvature and a subsequent
numerical calculation of the time-of-flight values for central and peripheral electrons (it is the
difference in these time-of-flight values that results in the time distortion).
However, for practical purposes it is more convenient to calculate the radii of curvature, required
for elimination of the time distortion, by using analytical formulae. These formulae are obtained in
the first part of the present talk.
The accelerating diaphragm (AD) used instead of the fine-structure grid [4] has a number of
advantages over the latter: the simplicity of its manufacturing, the possibility for operating the EOT
without the external optical system, the decrease of the photocathode reverse illumination and, as
it has been shown above, the improvement ofthe spatialresolution along the slit. The EOT luminosity
rises with increasing slit width in the AD of 2h; it is mentioned in ref. [4] that the image width of
the EOT screen does not depend on h (if an imaginary cross-over of the beam is displayed, which
arises due to the electron scattering by the AD). Hence, it follows that a broad (equal to hundreds
ofji) slit is more efficient than a narrow one (oftens ofp), the more so that it is easier to manufacture
a broad slit.
However, with rising width of the slit the spread of transverse velocities of electrons scattered from
the slit also increases, as well as the lens aberration, which causes blurringofthe imaginary cross-over
image and deterioration ofthe time resolution. The second part ofthe talk deals with the examination
of the above-mentioned phenomena. Restrictions imposed by the latter on the slit width of 2h are
obtained.
Framing/Streak Cameras Converters/Cameras III
Picosecond x-ray streak cameras
V. I. Averin,
Gennadii I. Bryukhnevich,
G. V. Kolesov,
et al.
Show abstract
The first multistage image converter with an X-ray photocathode (UMI-93 SR) was designed in
VNIIOFI in 1974 [1]. The experiments carried out in IOFAN pointed out that X-ray electron-optical
cameras using the tube provided temporal resolution up to 12 picoseconds [2]. The later work has
developed into the creation of the separate streak and intensifying tubes. Thus, PV-003R tube has
been built on base of UMI-93SR design, fibre optically connected to PMU-2V image intensifier
carrying microchannel plate.
Framing/Streak Converters/Cameras IV
Estimation of limit time resolution in image streak camera
V. G. Klementyev
Show abstract
A method is proposed for the estimation of image streak camera time resolutions which has its basis in the probability of a photodetector's recording of n photoelectrons for time T. The information about the dynamics of images forming in the electrooptic photochronograph and the estimates of time resolution are thereby achieved without supercharging the photocathode. Femtosec resolution can be established by means of pulses of tens of picosec resolution.
Gated Intensifiers
Electro-optical transducer employing liquid crystal target for processing images in real-time scale
S. S. Ignatosyan,
V. P. Simonov,
Boris M. Stepanov
Show abstract
The present hybridized electrooptical image-conversion transducer employs metal-dielectric-semiconductor-liquid crystal structures as optical targets in the electron beam-addressing mode. A theoretical analysis is conducted of instrument characteristics, and a tabulation is made of the functional capabilities of experimental test pieces.
X-Ray Techniques I
Generation of hard x-ray pulse trains with the help of high-frequency oscillating systems for fast processes recording
V. F. Romanovsky,
A. N. Kovalenko,
T. I. Sapozhnikova,
et al.
Show abstract
One of possible methods oftaking several successive pictures of a certain process in optically opaque
medium or inside enclosed volume is X-ray shooting ofthe process by means ofa pulsed X-ray source.
Development of such a source, which could generate stable and powerful hard X-ray pulses separated
by steady time intervals of minimal duration up to 1-2 microseconds, is a technically difficult tast.
All known attempts to solve this problem by improvement ofpulsed X-ray apparatus employing X-ray
tubes with autoelectronic emission or firing-emission cathodes have failed so far to bring marked
success. It is precisely this fact that explains why the authors of the presented paper have the
reasoning to consider that high-frequency pulsed X-ray apparatus PAflC-500011-1 they have developed
can be of a certain interest for both the investigators eximining fast processes and development
engineers of X-ray equipment.
Holography and Interferometry VI
Application of high-speed mirror chronograph 3CX-1 to plasma investigations in visible and medium infrared spectrum ranges
Show abstract
The unique possibilities ofpowerfu.l gas lasers operating on carbon dioxide for treatment of materials,
for production and heating of plasma, for exploring the atmosphere and other applications have been
represented in numerous studies into the physics of interaction between the infrared laser radiation
and gases, as well as condensed substances.
Framing/Streak Converters/Cameras IV
Time aberrations of combined focusing system of high-speed image converter
Irina M. Korzhenevich,
G. V. Kolesov
Show abstract
A rigorous analytical calculation of the time-aberration coefficient (TAC) is obtained for combined lenses whose accelerating electrode is in the vicinity of a cathode. The results thus obtained are verified by comparison with a least-squares method TAC calculation which requires no less than 10 electron trajectories in conjunction with the time-of-flight. By contrast, the present algorithm requires only two trajectories in the paraxial approximation and obviates the time-of-flight. The calculation neglects the magnetic field of the cathode-accelerating electrode region.
Holography and Interferometry VI
Interference visualization of infrared images
Nikolai G. Vlasov,
S. V. Korehazhkin,
Valentin V. Manikalo
Show abstract
Abstract not available.
Visualization and Applications IV
Recording of laser radiation power distribution with the use of nonlinear optical effects
S. V. Korehazhkin,
L. O. Krasnova
Show abstract
Interferential approach to registration of space-energetical characteristics of laser radiation is based
on reading due to interferometrical methods of changes of refractive index, appearing in specially
chosen medium during transformation through it oflaser radiation. A short overviews of non-linear
effects, which may be used for these purposes is demonstrated in work [ 1]. Most advanced nowdays
is usage of heat effect [2, 3]. Presented work is devoted to research of possible interferential registration
of laser beam profile at the expense of optical orientation of molecules in Kerr mediums and
due to re-orientation effect of director of nematic liquid crystals (NLC) in the field of laser wave.
Image and Data Processing
10 MHz multichannel image detection and processing system
Geert C. Damstra,
A. H. Eenink
Show abstract
A 16 channel 10 MHz image detection system is described that can be
used for streak photography. By use of 16 multiplexers (lOx) a frame
mode with 10x16 pixels is possible at 1 million frames per second
during 1.6 msec. The light from the image plane is collected by 160
high fibres. The reconstruction of the image is made on a specially
designed LED monitor or on a standard computer. Data transfer is
made by parallel-series-interface with two light fibres. The system
is used for high current arc research but other applications ate
possible.
Framing/Streak Converters/Cameras I
High-precision measurements of the 24-beam UV-OMEGA laser
Show abstract
The achievement of high density implosions of direct-drive laser fusion targets with the 24-beam TJV-OMEGA laser
system places very stringent requirements on the irradiation uniformity on target. Non-uniformities in the irradiation pattern
must not exceed -1% mis. One of the prerequisites for establishing the level of uniformity attained is the very precise
measurement of the laser power balance. This entails that the laser power in each of the 24 beamlines be diagnosed
simultaneously with a precision of 1%, over a dynamic range of 1000. The nominal laser pulse shape is a 600-ps FWHM
Gaussian, but this can vary between individual beamlines due to beam-to-beam differences in the nonlinear processes of
frequency conversion or gain saturation in the laser amplifiers.
We have set up a pulse-shape measurement system in which we pick off a small fraction of the energy in each
OMEGA beamline, linearly attenuate it, and couple the light into a multi-mode optical fiber for transport to a 24-channel
streak camera. The signals are multiplexed in 2 groups of 12 beams each. The streak-camera output is amplified with a dual
intensifier system and recorded on a photometric quality, cooled CCD camera. In this paper, we will report on the system performance and progress to date.
X-Ray Techniques I
Repetitive flash x-ray generator utilizing an enclosed-type diode with a ring-shaped graphite cathode
Show abstract
The fundamental studies of the repetitive type of flash x-ray generator utilizing
an enclosed-type diode with a ring-shaped graphite cathode for soft radiography are
described. This generator consisted of the following essential components: a
constant high-voltage power supply, an energy storage condenser of lOOnF, a highvoltage
pulser, a repetitive impulse switching system, and a flash x-ray tube. The
pulser employed a modified two-stage Marx circuit with a capacity during main
discharge of 425pF. The x-ray tube was of the enclosed-diode type and consisted of
the following major devices: a rod-shaped anode tip made of tungsten, a ring
cathode made of graphite, an x-ray window made of beryllium, a spattering shield
made of stainless steel, and a tube body made of glass. Two condensers in the
pulser were charged from 50 to 70kV, and the output voltage was about 1. 6 times the
charged voltage. Both the peak tube voltage and the peak tube current increased
according to increases in the charged voltage, and the maximum values of the
voltage and the current were about 90kV and 0. 5kA, respectively. The pulse width
was about lOOns, and the x-ray intensity was less than 2. OpC/kg at 0. 5m per pulse.
The repetition frequency was less than 50Hz, and the maximum size of the effective
focal spot was nearly equivalent to the anode diameter of 3. 0mm.
Disk-cathode flash x-ray tube driven by a repetitive type of Blumlein pulser
Show abstract
A repetitive flash x-ray generator utilizing a disk-cathode radiation tube is
described. This generator consisted of the following essential components: a high voltage
power supply, an energy storage condenser, a repetitive type of modified
Blumlein pulser, a turbo molecular pump, and a flash x-ray tube. This high-voltage
pulser consisted of the following major devices: two ceramic condensers with
capacities of 85OpF, a gas gap switch driven by electric field distortion, and a
coil. The two condensers were charged from -50 to -70kV, and the total capacity
during main discharge was 425pF. The peak voltages of the pulser output were about
-1. 4 times the condenser charged voltage. The flash x-ray tube consisted of the
following major devices: a rod-shaped anode tip made of tungsten, a disk cathode
made of graphite, a spattering shield, and a tube body made of acrylate resin. The
anode-cathode (A-C) space was regulated from the outside of the x-ray tube by
rotating the anode rod. The maximum values of the tube voltage and the current were
about 80kV and 1. 2kA, respectively. The maximum pulse width was about lOOns, and
the x-ray intensity was less than lpC/kg at 0. 3m per pulse. The repetition
frequency was less than 50Hz, and the maximum focal spot size was equivalent to the
anode diameter of 3. 0mm.
X-Ray Techniques II
Kilohertz range pulsed x-ray generator having a hot cathode triode
Show abstract
The fundamental studies for the repetitive pulsed x-ray generator utilizing a hot
cathode triode operated at high repetitive rates in the kllz-range are described.
This generator consisted of the followingessential components: a constant high-
voltage power supply, an energy storage condenser, a grid pulser, a DC-DC converter
for supplying grid bias voltages, and an x-ray tube. The x-ray tube was of an
enclosed-triode type and consisted of the following devices: an anode rod made of
copper, a plane anode tip (target) made of tungsten, a grid made from tungsten
wire, a focusing electrode made of iron, a hot-cathode (filament) made of tungsten,
and a glass body. The condenser which was attached to the anode electrode was
charged from 50 to 70kV, and the electric charges in the condenser were discharged
repetitively by the grid electrode operated by the grid pulser. The pulse width was
primarily determined by the pulse width from the grid pulser, the grid bias
voltage, and the cut-off voltage for thermoelectrons, and could be controlled to
about ips. The x-ray pulse height primarily increased according to increases in the
charged voltage at a constant grid bias voltage. The x-ray intensity was 1. 35nC/kg
at 0. 5m per pulse with a condenser charged voltage of 70kV, a grid bias voltage of
-1. 0kV, and the charged voltage of the grid pulser of 400V.
Repetitive flash x-ray generator operated at low-dose rates for a medical x-ray television system
Show abstract
The fundamental studies for the repetitive flash x-ray generator operated at lowdose
rates for a medical x-ray television system are described. This x-ray
generator consisted of the following components: a high-voltage power supply, an
energy storage condenser of lOOnF, a coaxial cable condenser with a capacity of
l000pF, a repetitive impulse switching system, a turbo molecular pump, and an x-ray
tube having a cold cathode. The condenser was charged from 40 to 70kV by a power
supply, and the electric charges stored in the condenser were discharged
repetitively by using a trigger electrode operated by an impulse switching system.
The x-ray tube was of the triode-type which was connected to the turbo molecular
pump and had a large discharge impedance in order to prevent the damped
oscillations of the tube current and voltage. The maximum tube voltage was
equivalent to the initial charged voltage, and the peak current was less than 70A.
The durations were about 2ps, and the x-ray intensities were less than 1. OpC/kg at
0. 5m per pulse. The repetition frequency was less than 50Hz, and the effective
focal spot size was equivalent to the anode diameter of 3. 0mm. For the x-ray
television system used in conjunction with this repetitive pulsed x-ray generator,
since the electromagnetic noise primarily caused by the high tube current was
decreased, noise-free stroboscopic radiography performed by the television system
could be realized.
X-Ray Techniques I
Fundamental studies for the high-intensity long-duration flash x-ray generator for biomedical radiography
Show abstract
The fundamental studies for the repetitive high-intensity microsecond x-ray
generator utilizing a cold cathode tetrode are described. This generator consisted
of the following essential components: a constant high-voltage power supply, an
energy storage condenser of 500nF, an main discharge condenser of lOnF, a turbo
molecular pump, a repetitive trigger device, and an x-ray tube. The condenser was
charged from 40 to 80kV, and the electric charges in the condenser were discharged
repetitively to an x-ray tube by a trigger device. The x-ray tube was of the
tetrode type which was connected to a turbo molecular pump and consisted of the
following major parts: a rod-shaped long anode tip made of tungsten, a cathode rod
made of graphite, a ring-shaped grid electrode, and a trigger electrode. The
trigger electrode was mounted at the center of the cathode electrode and was
insulated by a ceramic tube. The tube current was about 0. 4kA with a charged
voltage of 60kV. The x-ray pulse height and the time-integrated intensity increased
when the condenser charged voltage was increased, and the intensity was less than
2. OpC/kg at lm per pulse. The exposure times were about 2Ops, and the repetition
frequency was less than 50Hz.
X-Ray Techniques II
High-intensity soft-flash x-ray generator utilizing a low-vacuum diode
Show abstract
The fundamental studies on the high-intensity single flash x-ray generator having
a low-vacuum diode for biomedical radiography are described. This generator
consisted of the following essential components: a high-voltage power supply, a
high-voltage pulser with a coaxial oil condenser of l5OnF, a low impedance
transmission line made from four coaxial cables with lengths of 5. 6m and a total
capacity of 292OpF, a mechanical booster pump, and a flash x-ray tube. The x-ray
tube was of the diode-type which was connected to the booster pump with a constant
pressure of 1. 7Pa and consisted of the following major devices: a long anode tip
made of tungsten with a diameter (D) of less than 3. 0mm and a length (L) of 50mm, a
long cathode tip made of tungsten with a D of 1. 0mm and a L of 40mm, a
polyoxymethylene insulator, lead diaphragms, and an x-ray window made of
polyethylene terephthalate. The coaxial oil condenser in the pulser was charged
from 50 to 90kV, and the electric charges in the condenser were discharged to the
flash x-ray tube through a transmission line by using a gas gap switch with a highcurrent
capacity. The peak voltage increased according to increases in the
condenser charged voltage and its value was more than the charged voltage. The peak
current primarily increased when the charged voltage was increased, and its value
was less than 4OkA. The pulse width of the flash x-rays ranged from 60 to 8Ons, and
the time integrated x-ray intensity with a charged voltage of 90kV and an anode
cathode (A-C) space of 3. 0mm was about 4pC/kg at 1. Om per pulse the source. The
effective focal spot size was primarily determined by the diameter of the anode
tip, and its value was about 3. 0mm when an anode diameter of 3. 0mm was employed.
X-Ray Techniques I
Repetitive flash x-ray generator as an energy transfer source utilizing a compact-glass body diode
Show abstract
The studies of a repetitive flash x-ray generator as an energy source achieved
with a compact diode with a permeable anode are described. This source consisted of
the following essential components: a constant negative high-voltage power supply
of up to -100kV, a modified two-stage Marx pulser, a repetitive trigger device, and
an x-ray tube. Two condensers in the pulser were charged from -50 to -80kV, and the
output voltages (no-load) were less than -130kV. Since the capacity of each
condenser was 85OpF, the total capacity during discharge was 425pF. The maximum
tube voltage and the tube current were about 85kV and 0. 3kA, respectively. The xray
pulse widths were less than l2Ons, and the repetitive rate was less than 40Hz.
The time-integrated x-ray intensity was about 25pC/kg at 24mm per pulse with a
charged voltage of 60kV and an anode-cathode (A-C) space of 9. 0mm, and the maximum
size of the x-ray source was equivalent to an anode diameter of 27mm.
Poster Session
Improved image quality from retroreflective screens by spectral smearing
Show abstract
The resolution in an image formed using a retroreflecting screen can be limited by the structure of the screen.
Improved image quality is possible by smearing the image at the screen with a diffraction grating.
Image and Data Processing
Digitize your films without losing resolution
Show abstract
The use of a high resolution linear camera film scanner to digitize cine film in order to automate motion
analysis, is discussed. By using high quality optics, high precision mechanics and a 2592 linear array camera,
a resolution of 6 micrometers (.25mu) at a rate of 1 .3 frames per second is achieved. The whole film is
scanned, in order to collect timing and reference marks located anywhere on the film. Through the integration
of the Film Scanner with an analysis computer, a fully automated motion analysis system has been realized.
Visualization and Applications I
Streak and smear: a definition of terminology
Show abstract
Streak and Smear are two well known and extensively used techniques of High Speed
Photography. Examples will be given of applications in weapons research. Streak
aptly describes its technique whereas smear does not. A new title is suggested
which congress is asked to endorse.
Visualization and Applications II
Evolution of high-speed photography and photonics techniques in detonics experiments
Show abstract
New optical laser techniques are reviewed and classified according to the kinematic or thermodynamic parameters to improve the knowledge of detonics problems. These optic, electronic, and optoelectronic techniques include spatial observations of phenomena vs. time which are based on a framing rotating mirror or an opto-electronic camera with mirrors and optics; chronometry of events; measurements of continuous stress vs. time; velocimetry measurements of free surfaces by interferometry; the Doppler laser interferometry technique; and an instantaneous velocity field technique.
Framing/Streak Cameras Converters/Cameras III
Measurement of triggering instabilities of Imacon 500 streak cameras
David John Bowley,
Philip Rickett,
A. V. Babushkin,
et al.
Show abstract
5±lps, spectrally limited optical pulses with less than 0.5% energy
instability, generated by hybrid mode-locked, and passive feedback controled
YA1O :Nd3 crystal laser were employed for measurements of Imacon 500 streak
cameas triggering instabilities. These cameras have operated in streak mode with
the streak speed of SxlO9cm/s. Synchronization signal was produced with the help
of a standard avalanche photodiode. Due to very high stability of the utilized
picosecond laser pulses, it was possible to measure with few picosecond accuracy
the jitter variation of Imacon 500 cameras. It was found that for some of them,
the triggering jitter does not exceed lOps RMS. In the present communication we
will discuss jitter dependence on triggering pulse amplitude, as well as on the
mains voltage variations.
Framing/Streak Converters/Cameras II
Some comparative results of two approaches in computer simulation of electron lenses for streak image tubes
Show abstract
The results of two different approaches in simulation of image converter tube
electron optics are given. The first approach is based on aberrations technique, and
the second one is connected with trajectories analysis. To compare the efficiency of
both techniques we have chosen an electron-optical system of the very well- known
time analysing image-converter tube of PVOO1 type. Our digital results reveal much
higher calculation stability for the aberration technique when the latter was used
for calculation of the image tube parameters near the tube axis. For the
photocathode points shifted of the tube axis, both approaches exhibit the similar
behaviour. Furthermore, for the photocathode peripheral areas the software based
on trajectories analysis seems to be more preferable. It is evident that further
development of both techniques will provide the same accuracy and calculation
stability over the whole photocathode area for various type of electron lenses.
Framing/Streak Camera-Applications
Two-dimensional electron-bombarded CCD readout device for picosecond electron-optical information system
K. N. Ivanov,
N. I. Krutikov,
Sergei K. Naumov,
et al.
Show abstract
Two-dimension readout device based on a 520X580 pixels format, electronbombarded
CCD was designed for detection and analysing pictures taken from the
luminescence screens of picosecond image converter cameras. Block-diagram,
construction peculiarities of the readout device as well as the developed software
for external XT-type computer will be presented and discussed. Our readout device
is operated in two different modes: 1. CCD scanning mode with the frame
transaction and 2. CCD continuous scanning mode with the scanning halt during
CCD exposure time. The second mode of operation which provides continuous CCD
cleaning from dark signals is the principal one. In both modes of operation there
is a wide range of the CCD pixels scanning rate (from 150 kHz to 10 MHz).
Video-signal is converted into 8-bit digital code at the scanning rate faster than
1 MHz and into 10-bit digital code at the lower scanning frequencies. The developed
frame memory of 1 Mbite capacity may be formatted either in
lO24XlO24X8bitXlframe, or 5l2X5l2Xl6bitX2frames, or 5l2X5l2X8bitX4frames. For
continuous presentation of the frame memory content the system is supplied with a TVmonitor.
The spatial resolution of the readout device together with image converter
camera is better than 25 line pairs/mm at 30% MTF. The inherent EB CCD readout
device threshold sensitivity is 30-40 photons per pixel at 530 tm input radiation
wavelength. Its dynamic range is about 100.
Laser-produced plasma x-ray diagnostics with an x-ray streak camera at the Iskra-4 plant
Arkadi G. Berkovski,
Yuri Ivanovich Gubanov,
Ivan G. Pryanishnikov,
et al.
Show abstract
An X.raj streak camera with an Xray streak tube used for laser-produced plasma soft Xrays measurement is described, and experimental results are given.
In investigating short-Jived high temperature plasma, and inertial control of
thermonuclear fusion in particular, measurement techniques based on registration of X-.rays emitted by the investigated object are of great value. They
make it possible to get much information on the dynamics of plasma evolution,
its form, dimensions, temperature, and density.
The instrumentation used for these purposes must meet the following main requirements:
it must provide measuring X-.rays time, intensity and spatial coordinate;
its spectral range must be wide, from relatively hard to extremely soft X-rays
(tens of keV to tens of eV quantum energy);
its tiive resolution must be high (of the order of 10 s).
At present the only type of an instrument satisfying the above requirements is
a streak camera with an X-ray' streak tube (X'RST).
The XRST operation principle has been known long ago: the photocathode converts the incident X-rays into an electron beam, which is accelerated and focused by the electric fields onto the output phosphor screen, where a visible
image of the incident radiation cross-.section appears. The image travels very
rapidly over the screen, resulting in a time sweep.
The design and development of such kind of instrumentation was begun in our
country more than 10 years ago. In 1986 the All-Union Research Institute of
experimental Physics, in collaboration with the Research Institute of Pulse
Technique, designed and built first instruments with satisfactory parameters.
These instruments found use in laser thermonuclear fusion research.
Mainly two types of X-.ray streak tubes are used for X-.ray spatial-temporal
structure registration:
special type X-ray streak tubes with X-ray sensitive photocathodes and transparent for X-ray input windows, and
X-ray streak tubes with X-ray sensitive photocathodes and without an input win
dow; these tubes are joined to a continuously pumped-out vacuum plant with an
X-ray source inside it. The quantum energy lower limit of the registered X-rays depends on the input
window thickness and. material, which determine its transparency for the radiation being investigated.
One-dimensional CCD linear array readout device
A. M. Borodin,
K. N. Ivanov,
Sergei K. Naumov,
et al.
Show abstract
Simple, reliable, and low-cost 1D, CCD linear array readout device is described. The CCD array contains 1000 resolvable pixels. The device threshold sensitivity is 1.5 10-13 J/pixel at dynamic range of not less than 103.
Poster Session
Orthogonal shadowgraphic nanolite stations
Eduard A. Celens,
A. Chabotier
Show abstract
The orthogonal photography aims at the restitution in the
tridimensional space of the position and the attitude of a physical
object.
In our particular application of the orthogonal photo-graphy, the
object is a small caliber projectile in flight and each station
realises the orthogonal shadowphotography of the projectile in true
size.
Using several mutually aligned stations along the trajectory, the
position of the center of gravity as well as the attitude in space
of the projectile can be restituted. Using this information the
spatial angle of attack and its rate of variation can be deduced.
In comparison with the photography based on reflexion, the
shadowphotography has the advantage that some characteristics of
the supersonic flow around the projectile are visualised.
Visualization and Applications V
Application of IR photorecorders based on ionization chambers for fast processes investigation
Vladimir V. Egorov,
Valeri P. Lazarchuk,
Vasili M. Murugov,
et al.
Show abstract
There are qiven the research data of photoqraphic systems characteristics
based on the ionization-type semiconductive chambers with photodetectors of
different types.
The recorder dynamic range of iO , speed of response of lO sec..
resolution of 10 lines/rrui and sensitivity of 10 44i0 'J/cia2 in 1-10,6 microns
spectral ranqe were obtained by optimizinq the photodetector parameters. the
chamber desiqn and its operatinq mode.
Enerqy distribution in beams of pulsed NF and DF chemical lasers in the
mode of "maqnifyinq glass of time" was studied usinq semiconductive chambers.
It is shown, that the energy distribution on the lasers end has larger
irregularity ('s, 102 times) than at the inteqrated survey.
The information has been received about space - time responses of CO2
lasers radiation with the aid of semiconductive chambers, operatinq in
a modulation mode of emission at the chamber input . and on the chamber
electrodes there is applied pulsed supply voltaqe with a photoqraphy
freuenc of 20-100 Hz.
There are qiven the results of recordinq with semiconductive chambers of
the heat fields structures of different oblects over a temperature range
600-2000"C. which are heated by a shock wave or fl at the supersonic
velocity at the frame exposure time lO÷iOsec.
Poster Session
Slapper detonator flyer microphotography with a multiframe Kerr cell and Cranz-Schardin camera
Olin K. McDaniel III
Show abstract
Critical to all Exploding Foil Initiator or "slapper" systems is
the bridge-barrel--flyer combination, which needs to be optimized for
each application and fire set. The best way to do this is with
optical diagnostics. Parameters desired are the flyer position,
shape, and velocity versus time as a function of charge voltage and
discharge current. Multifraine microphotography of a flyer moving down
a barrel is one solution but poses several problems, one of which is
the insufficient depth of field of the optics system. If most of the
length of the "infinite" diameter barrel is removed and the flyer is
viewed from the side, then its axis of movement will remain in focus,
displacement versus time will be recorded, and its shape inferred.
Bridge burst may also be photographed to guarantee against shorting
and attain maximum performance.
The flyer event takes place in about 80 nsec. , necessitating a
100 million frame per second camera for 8 frames. Kerr cell cameras
are seldom used but provide superior spatial resolution to electronic
image convertors, are more rugged and much less expensive. Laser
microphotography is more conmion. After a review of the principles of
Kerr cells, two multiframe Kerr cell cameras will be described. Using
a nitrogen laser pumped dye system as backlight, the Kerr cameras may
photograph nonluminescent objects. Minus the Kerr cells the multifranie
optics and laser may be used in a Cranz - Schardin mode.
Visualization and Applications III
Determination of burst initiation location and tear propagation velocity during air burst testing of latex condoms
Show abstract
The stress testing of latex condoms by an air burst procedure has been slow in
gaining industry acceptance because questions have been raised regarding the
influence of the test apparatus on the likelihood of breakage occurring where the
condom is attached to the inflation device. It was desired to locate the areas at
which the condoms tend to burst and thus corroborate or disprove these claims.
Several factors associated with the bursting condom demanded the use of special
instrumentation to detect arid study the burst initiation process. Microsecond
duration electronic flashes were used for the initial stages of the investigation.
Although the absolute point of initiation of a given burst could not be photographed,
these high speed studies tend to indicate that the most likely place for high quality
condoms to break is not where they are attached to the inflation device but at an
intermediate area between the base and the tip of the condom. In addition, tear
propagation characteristics and velocities were determined with a delayed-flash
technique, a double-slit strip method and a rotating drum framing camera.
Visualization and Applications IV
Advantage of simultaneous streak and framing records in the field of detonics
Show abstract
The simultaneous recording of an event with frames and streak records without parallax (using the same camera) allows streak records to be directly related to strictly spatial events. While the frames give spatial information of the overall event, they often exhibit motion blur due to the limited exposure possible in detonative processes. Nevertheless, they indicate whether the streak record was made in the symmetry plane and whether phase velocities were recorded in the streak records.