Historical Survey Of High Speed Photography In Japan
Author(s):
Tsuneyoshi Uyemura
Show Abstract
This paper shall begin with a brief history of photography in Japan. It is said to be in 1840 that Japan imported its first Daguerreotype camera from Holland. Records show that Mr. Toshinojo UENO photographed some portraits of Lord Nariakira SHIMAZU, the chief of the Satsuma feudal clan, on June 1, 1841. Because of this, the date was designated in 1951 as Memorial Day of photography, when we have photography-related celebrations every year.
Survey Of Recent High-Speed Photographic Developments In North America
Author(s):
Hallock F. SWIFT
Show Abstract
High-speed photographic activity in North America during the past few years has been concentrated in a few important areas. Electronic cine and streak camera capability has increased rapidly under pressure from the controlled thermonuclear fusion program. Micro channel electronic image intensifier plates are providing great gains in sensitivities of modern high-speed cameras of all types. Cine x-radiography is rapidly gaining attention and is expected to become a major research field in the near future. Pulsed lasers are finding increasing applications as fast, intense light sources for conventional photography. They also provide illumination for fast holographic cameras. Finally, we expect considerable activity in the near future when interrelations between these new technology areas are exploited.
Survey Of High Speed Photography In The United Kingdom
Author(s):
G H Lunn
Show Abstract
The most difficult task to do in high speed photography is to define exactly what high speed photography is. Basically it is the use of photographic means to record and analyse subjects which change too rapidly for the eye to follow. But when one examines the index of subjects considered at these International Congresses, it is soon obvious that the term 'photographic' is quite elastic and includes radiations outside the visible spectrum, detectors other than photographic emulsions and will soon include other methods of recording and storage than films. This is confusing and disturbing to newcomers to the subject but taken by the experienced only as a natural extension into new techniques to achieve the same ends.
Techniques And Applications Of Xenon Flash
Author(s):
Harold E. Edgerton
Show Abstract
Discharge lamps filled with xenon gas through which electrical capacitors are discharged have found many applications for producing pulsed energy in photography and energy discharges. The object of this paper is to review sane of the more important characteristics of flash lamps. The flash duration of specific flash lamps when operated from a given capacitor charged to same known voltage is dis-cussed below. The dimensions of the lamp are one of the most impor-tant factors since the response of the lamp to the circuit is greatly influenced. Experimentally measured flash duration as a function of capacitance and voltage is given in graphical form for one type of flash lamp. Rules (approximate) are given for converting the data into data for other flash lamps and circuits. Efficiency of a xenon lamp can be as high as 5 candela/watt for a lamp that is loaded so that the arc fills the inner diameter of the constraining tube. The life of the xenon lamp can be many, many flashes. In fact, this is one of the lamp's strong points. The spectral distribution of the light from a xenon lamp closely approximates daylight with a small shift to the blue if the applied voltage is high. Details of a specific flash lamp showing the nature of the spectral output is given. A list of some of the oractical uses of electronic flash lamps is given and discussed.
Repetitive Sub-Microsecond Light-And X-Ray Flash Techniques And Applications In Precision Analysis Of Motions And Flows
Author(s):
F. Frungel
Show Abstract
The paper deals with the generation and practical applications of -submicrosecond light-and x-ray flashes, their discharge charac-teristics and spectra in inert gases in the visible range. Latest de-signs and applications of X-Ray Flash Equipment will also be treated, from single flash to long burst High Speed Radiography. The already well-proven Spark Tracing Method for investigation of air flows by means of a masseless indicator, viz, the electric spark will also be discussed. The paper is supported by a great number of illustrations showing practical applications in various fields of science and research, comprising almost all known high speed photographic techniques, from Shadowgraphy to Schlieren and from single flash to high frequency bursts.
Techniques And Applications Of Intermittent And Rotating-Prism Cameras
Author(s):
William G. Hyzer
Show Abstract
The technique of high-speed cinematography, based on the application of intermittent and rotating-prism cameras, is widely accepted today as a standard method of chronoscopic recording in virtually every field of science and technology. Significant improvements have been made in recent years in the mechanical, optical, and electronic design of these cameras, but equally important is the progress made in developing a general methodology for the efficient application of these instruments and techniques to specific scientific and technological problems. This paper develops these methods, describes the mathematical techniques involved and offers specific guidelines for optimizing their application.
Techniques And Applications Of Rotating Mirror Cameras
Author(s):
Sidney J. Nebeker
Show Abstract
A discussion of rotating mirror streak and framing cameras with emphasis on aspects of the nature of the instruments which determine useful techniques and application. Their characteristics compared, in a few cases, with other research cameras.
Current Status On Image Processing In Medical Fields In Japan
Author(s):
Kazuhiko Atsumi
Show Abstract
Information on medical images are classified in the two patterns. 1) off-line images on films-x-ray films, cell image, chromosome image etc. 2) on-line images detected through sensors, --- RI image, ultrasonic image, thermogram etc. These images are divided into three characteristic, two dimensional three dimensional and dynamic images. The research on medical image processing have been reported in several meeting in Japan and many fields on images have been studied on RI, thermogram, x-ray film, x-ray-TV image, cancer cell, blood cell, bacteria, chromosome, ultrasonics, and vascular image. Processing on TI image useful and easy because of their digital displays. Software on smoothing, restoration(iterative approximation), fourier transformation, differentiation and subtration. Image on stomach and chest x-ray films have been processed automatically utilizing computer system. Computed Tomography apparatuses have been already developed in Japan and automated screening instruments on cancer cells and recently on blood cells classification have been also developed. Acoustical holography imaging and moire topography have been also studied in Japan.
Digital Image Processing For Motion Analysis
Author(s):
Morio Onoe
Show Abstract
Digital image processing now can be economically applied to the motion analysis of objects taken by the high speed phtography. This paper will review some of common techniques. The identification of objects, motion detection and motion tracking are discussed. These procedures are neither independent nor in sequence. Forward and backward feedbacks of knowledges accumulated during processing are important in order to reduce the processing time and increase the reliability.
An Assessment Of Hybrid Optical Systems For Information Processing
Author(s):
Brian J. Thompson
Show Abstract
Optical processing methods appear to have a viable future when used as a component part of a hybrid system. The other parts of the hybrid systems are combinations of electronic, electro-optical, and digital subsystems. The important components that are linked with the optical systems are: input transducers for incoherent to coherent light conversion and for acoustic or electron beam to coherent light conversion, addressable filters, microprocessors, single fast detectors and detector arrays. The various classes of systems that use either Fourier plane or image plane detection are reviewed with illustrative examples given for each of the major classes of systems.
Recent Developments In Laser Doppler Anemometry At The German-French Research Institute Saint-Louis (ISL)
Author(s):
Rudi Schall
Show Abstract
Laser velocimetry took its origine at ISL more than 10 years ago in the form of fringe anemometry. Though there is now industrial equipment available, special applications call for new versions. Air turbulence spectra up to 50 kHz could be obtained from precise fringe anemometer measure-ments. This shows the relevance of high speed methods to investigate fast fluctuating phenomena of longer duration. Successful tests to operate an airborne LDA-system open new ways in aerodynamic research. Finally, a new two-beam inter-ferometer of extreme sensitivity was used to determine from the Laser Doppler shift flow or material velocities in shock tube and ballistic investigations.
High-Speed Photography Of Explosion In Japan
Author(s):
Y. Mizushima
Show Abstract
A historical review of Japanese explosion studies from a point of view of highspeed photography and a simple elucidation of explosion are presented. Proper understanding is indispensablein taking a high-speed photography for analysis. Gas evolution,flame ignition,flame expansion,smoke generation,shock wave formation,its passage, structure breakage, rock movement etc. are the important feature of explosion to be studied with a high-speed camera. Examples referring to the above items are abstracted from Japanese literature. The first instance is a study on muzzle flames with a rotating disk camera which uses photographic dry plate. A Cranz-Schardin system then appears. After the War adding to the above cameras 16 mm cinecameras are widely brought into use. Rotating mirror type cameras are also used in shock wave studies. Besides X-ray flash sources are effectively used.
High Speed Photographic Analysis Of Stress Wave Propagation, High Velocity Deformation, And Fracture In Impact Of Solids
Author(s):
Kozo Kawata
Show Abstract
Merit and demerit of several high speed photographic techniques in applying to high speed photoelastic analysis of stress wave propagation, high velocity deformation, and fracture in impact of solids, are briefly surveyed. Some characteristic cases of high speed photoelastic analysis are reported. They are concerned with the problems of dynamic stress distribution by stress wave propagation, crack propagation, and supersonic disturbance source travelling in solid, etc. Strain and fracture behaviour analysis of metallic specimens in high velocity tension test up to 200 m/ sec is also reviewed and obtained crystal lattice systems effect in high velocity tensile breaking elongation is presented.
Developments Of Picosecond Photonics For Laser Fusion Research
Author(s):
Chiyoe Yamanaka;
Tatsuhiko Yamanaka
Show Abstract
Laser Fusion Research depends on the development of high power lasers which can deliver a few 10 TW laser light in 100 picosecond. The implosion process of a fuel pellet by laser irradiation can only be measured using the pico second photonics with pm spatial resolution. Recent status of these developments is presented.
Recent Developments In Picosecond Photochronoscopy
Author(s):
D. J. Bradley
Show Abstract
Recent developments in the techniques of generation and measurement of picosecond and sub-picosecond pulses from mode-locked lasers are reviewed. Particular attention is paid to frequency tunable, bandwidth-limited pulses from dye lasers, especially the C.W. dye laser. In measurement the main emphasis is put on the rapid advances of the last few years in ultrafast streak-cameras, and the recent developments' in streak-camera synchronization to a C.W. mode-locked laser is described. Future prospects for shorter wavelength pulses in the UV and VUV are briefly considered.
Image-Converter Diagnostics Of Laser And Laser Plasma In Pico-Femtosecond Region
Author(s):
M. Ya. Schelev
Show Abstract
In the present communication we would like to outline some new trends in development of picofemtosecond image-converter diagnostics for laser and laser plasma research on the basis of the recent works done in P.N.Lebedev Physical Institute. The discussion of the following subjects will be included: new generation of picosecond image-converter tubes(ICT), pulsed control circuitry, late proto-type of picosecond image-converter cameras (ICC), test installation consisting of Nd:glass and YAG lasers for production the ultra-short pulses and sinusoidally modulated radiation, methods and techniques for image tube and camera dynamic measurements in IR, visible and X-ray spectral regions. Also discussed are the image processing technique for pictures taken with picosecond ICC in order to correct the geometrical distortions, enhance pictures quality and evaluate parameters of the input signals through their recorded images.
Techniques And Applications Of Image Converter Cameras
Author(s):
Roger Hadland
Show Abstract
The essential role of image converter cameras for high speed diagnostics is illustrated by a variety of new techniques and applications. Large calibre projectiles can be recorded in flight by sunlight, eliminating the need for additional illumination. Projectiles leaving the muzzle, and on impact, can be recorded using an X ray technique under conditions impossible for conventional photography. Improvement in frame geometry and resolution is illus-trated by photoelastic crack propagation studies. Subnanosecond techniques include development of a picosecond X ray camera with spectral sensitivity into the U.V. and include application to laser fusion studies. Also described are a new-approach to single shot sub-nanosecond photography and application of a continuous circular scanning camera to record visible radiation generated by a particle accelerator.
A Superior 16MM Reversal Color Film For High-Speed Motion Picture Photography
Author(s):
A.Earl Quinn
Show Abstract
Eastman Ektachrome Video News Film High Speed 7250 Tungsten (VNX) is superior color film for use in 16mm high-speed motion picture photography. VNX 7250 film features an exposure index (E.I.) of 400. This film re-quires the VNF-1 or the RVNP process and it may be forced or push-processed to an E.I. of 6400 (4 camera stops) under certain conditions. It is available for high-speed camera use in Spec. 430 (100-ft. spools) or Spec. 434 (400-ft. spools). A 16mm silent, high-speed movie film has been prepared to demonstrate the results of forced processing of underexposed high-speed camera footage featuring mechanical motion too fast to be observed by the unaided eye.
Sensitive Materials For Image Instrumentation
Author(s):
Eiichi Mizuki
Show Abstract
The following four materials or phenomena are described in this report. (1) In contrast to wet-developing photopolymer systems now widely used, a new dry-developable photopolymer pro-cess (peel-apart process) for production of printed circuits and printing plates are described. (2) A real-time, high-resolution laser recording dry film consisting of a transparent substrate, an evaporated thin-film, and a protective overcoat is described. (3) A photographic material consisting of a silver halide emulsion layer formed on a metal or metal oxide layer deposited on a transparent support, and processes therefor are described. (4) Certain silver halide materials intended for high intensity and short time exposure were developed, with physical measurements made on these materials being described.
Recent Flow Visualization Studies
Author(s):
Tsuyoshi Asanuma
Show Abstract
With an idea of elucidating a physical phenomenon from visual observation, devices to enable to observe and survey directly a large portion of a flow field, in general, have been called as the flow visualization techniques. They allowed us to facilitate the understanding of the basis of theoretical analysis for various flow problems. Relying upon the results of the symposia on flow visualization in Tokyo,i.e. the annual domestic meetings since 1973 and the first international conference last year, I would like to present a survey of recent development and improvement for each of the flow visualization techniques along with the typical applications and the latest tendencies.
Moire Topography As A New Means Of The Three Dimensional Measurement
Author(s):
Hiroshi Takasaki
Show Abstract
The properties of moire fringes and their applications to the three dimensional measurements will be reported. The three types of typical techniques of the moire topography, an extension of the shadow moire technique which forms the basic method of the moire topography, the projection type, and the grating hologram type will be explaned respectively, putting stress on the merits and the demerits of each method. A brief explanation on the modern trend to introduce the TV techniques to the moire topography will be also made.
Improvement Of A Cranz-Schardin Camera
Author(s):
Alain Henchoz
Show Abstract
The high speed photography of ballistic experiments by means of a Cranz-Schardin Camera would very often require a multiple time scale spark controller. In the model described hereafter, the digitally adjusted time interval between two successive frames is kept constant within a group of 4 frames, but can be different in the other groups. As an additional feature a Velocity Dependent Delay ensures a precise triggering of the camera. For instance, the first frame can be synchronized with the impact, regardless of the velocity of the projectile.
Photographic Instrumentation In The VKF Aeroballistic Track Facilities
Author(s):
Roy E. Hendrix;
Paul H. Dugger
Show Abstract
This paper deals with high-speed photography employed in the latest type of ground simulation facility -- the aeroballistic track facility. Two such test facilities are operational in the von Karmgn Gas Dynamics Facility (VKF), and ultra high-speed laser photography, photopyrometry using image intensifiers, X-ray shadowgraph photography, and other more conventional photography serve as primary measurement systems. Descriptions of these systems are given, and photographic examples of their applications in the track facilities are provided.
Applications Of Fiber Optics To Ultra High Speed Photography
Author(s):
A. E. Williams
Show Abstract
A high speed photography technique is described which combines a very bright light source, optical fibers, and a rotating mirror camera to obtain sub-microsecond definition of high speed events. Applications described here include the measurement of the onset of detonation in an explosive, the measurement of projectile velocity, and the evaluation of planarity in a shock front. The fiber optics assemblies may also be used as image dissection devices, converting macro pictures to slit images. The previous work by W. Hertz is reviewed and modifications to this technique are described.
Time Correlated Multi Streak
Author(s):
M. Held;
P. Nikowitsch
Show Abstract
The Multi-Streak-Technique (MST) and the Orthogonal-Multi-Streak-Technique (OMST) provide the possibility to measure the break-through of a detonation wave at the front of a high explosive charge with very high time and spatial resolution. The time correlation of discrete analogous recording within single streak lines at a Multi-Streak recording is not known a priori. The time differences have to be determined by computation. For this purpose the respective distances between the streak lines along with the writing speed and the spatial imaging factor of the recording camera have to be known accurately. The problem can be solved by the insertion of optical fibres at defined locations within the streak slits and the consecutive reunion of the fibres at a reference slit. Thus the time differences can be read out directly from the recording.
Microsecond Streak Technique For Film Camera With 50 M/S Filmtransport
Author(s):
P. Nikowitsch;
K. Reichel
Show Abstract
By means of classical kinematographic techniques overall spatial data about the object is obtained at discrete times, whereby taking into account rather poor accuracy. In the case of streak techniques a fundamental gain in accuracy concerning kinematic quantities is reached, but spatial information is low. A combination of both framing and streak recording leads to a measuring method avoiding the draw backs of either method. A standard 16 mm rotating prism film camera with a maximum of 50 m/s of film transport is driven as a streak camera, yielding recordings with the velocity vector of the object beeing perpendicular to the streak slit. By means of this technique pseudo frames are created with time resulution for the kinematic quantities in the microsecond region.
Large-Format 70-mm High-Speed Framing Camera
Author(s):
Larry L. Shaw;
John B. Sonderman;
Lynn G. Seppala
Show Abstract
The authors describe a new large-format synchronized high-speed framing camera. The camera has a framing rate of 2.5 x 106 frames/ sec with a frame size of 64 by 38 mm and a 26-frame record length. The new camera uses a beryllium rotating mirror with an isosceles-triangle cross section that allows a large mirror surface of 36 by 24 mm at the design speed of 104 revolutions/sec. Magnification of 1.8 in the internal optics of the camera gives the larger picture on 70-mm color film.
Light Emitting Diodes As Short Duration Light Sources
Author(s):
I. M. Hutchings;
D. R. Andrews
Show Abstract
The use of GaAsP light emitting diodes as pulsed light sources for high-speed photography is discussed. Two applications are des-cribed: single-shot photography with pulses ca. 1 p,s long, and stroboscopic visualization of ultrasound with 50 ns flashes. The luminous efficiency and current capacity of the LEDs was considerably enhanced by cooling them to 77 K in liquid nitrogen.
Investigation Of A High Power Tunable Dye Laser
Author(s):
A. Hirth;
K. Vollrath;
G. Gulitz
Show Abstract
A tunable organic dye laser pumped by a large co-axial flashlamp is described. The influence of the parameters of the electrical driving circuit and of the dye solution on the lasers output energy is investigated. With a rhodamine 6G solution in methanol, pumped by 10 kJ electrical energy, laser pulses of 2.5 µs duration are ob-tained. Conversion efficiency attains 0.46 %.
High Intensity Nanosecond Standard Light Source
Author(s):
Heinz Fischer
Show Abstract
The "Nanolite" represents an inexpensive nano-second standard light source extending from the near uv to the infrared spectral range. Position stability of the spark channel, reproduceable light amplitudes and constant pulse shapes offer a variety of applications.
High Power, High Intensity, And Extremely Short Light Source Of Glass Laser System "Gekko IV"
Author(s):
Y. Kato;
J. Kuroda;
Y. Mizumoto;
K. Yamada;
K. Yoshida;
C. Yamanaka
Show Abstract
A short pulse, high power laser system provides oppor-tunities for producing and diagnosing various kinds of high speed phenomena such as the study of radiative and kinetic properties of laser-produced plasmas. We have developed a high power phosphate glass laser system for laser fusion research at Osaka University. This four beam system de-livers output energy of 2 kJ in 1 ns and output power of over 4 TW in 10 ps. The peak intensity at the focal point reaches ≈5x1017 W/cm2. Characterization of the system performance based on simulation calculations and experimen-tal measurements are described.
PhC-4 New High-Speed Camera With Mirror Scanning
Author(s):
A. O. Daragan;
B. G. Belov
Show Abstract
The description of the optical system and the construction of the high-speed PhC-4 photographic camera with mirror scanning of the continuously operating type is given. The optical system of the camera is based on the foursided rotating mirror, two optical inlets and two working sectors. The PhC-4 camera provides the framing rate up to 600 thousand frames per second.
One Frame Camera With Digital Display For Registration Of Pulse Laser Radiation Energy Distribution
Author(s):
B. I. Aijoshin;
Yu. A. Drozbin;
V. E. Prokopenko;
B. M. Stepanov
Show Abstract
One frame camera with a digital display is intended for measurement of energy distribution in a pulse laser radiation beam cross-section in a 0.4+15 mom spectral range in framing mode. Investigated radiation pulses are of 5.10-3 + 10-6 s duration. Radiation energy density range is 0.05 + 5 J/cm2. Number of resolvable picture elements totals 100. Error of relative energy distribu-tion measurement is + 5%. Error of absolute energy value measurement is ± 15%.
GSFK Waiting Type High-Speed Camera
Author(s):
G. I. Belinskaja;
V. Ya. Bezmenov;
V. H. Veselovskaja;
L. P. Gurjashkin;
A. S. DuBovik;
I. A. Koroliov;
V. T. Laznikov;
V. I. Ribakov;
T. I Chernova;
V. A. Yakovlev
Show Abstract
High-speed photographic waiting type GSFK camera is intended for the investigation of high-speed processes both in the reflected light and with shadow and interferometric devices. Connecting optical attachments are provided for this purpose. The camera operates in framing and streak modes. The registration is provided in the vi-sible range of spectrum in a waiting mode, i.e. no synchronization to the event is required.
Methods Of Reducing High-Speed Raster Camera Scanning Mechanism
Author(s):
V. V. Garnov;
A. S. Dubovik
Show Abstract
The description of original high-speed raster camera schemes with the image mechanical scanning are given. These schemes allow to decrease rotating details sizes and image parallax significantly to increase rotating disk speed and framing rate to expand camera using possibilities.
The Peculiarities Of Calculation Of High-Speed Photographic Cameras
Author(s):
V. V. Trofimenko
Show Abstract
The main problem of high-speed mirror camera development is to create a mirror scan unit. Principle problems connected with the mirror scan unit development are considered. A new extended calculation method for the determination of its main parameters is given. A computer calculation method is also presented. The theory presented provides optimal choice and determination of all parame-ters of the mirror scan unit. It allows to achieve a high quality image, maximum relative aperture of the instrument and high informative ability.
High-Speed Cinematography Of Transient Events Using Sub-Nanosecond Pulses At Different Wavelengths
Author(s):
M Hugenschmidt;
K Vollrath
Show Abstract
A multichannel atmospheric pressure N2-laser is describ-ed delivering five pulses at repetition rates of several tens of MHz and pulse durations below 1 ns. The UV-pulses at 3371 A have first been applied to study laser induced plasmas. In a second experiment they are used to pump suitably chosen dyes. It is shown that such pulses at different wavelengths are well suited for interferometric measurements up to frequencies of SO MHz. Thereby the individual interferograms are separated optically without the use of rotating mirror cameras or image converters.
Moire Contouring And Applications To Highspeed Photography
Author(s):
Toru Yoshizawa;
T. Eiju;
S . Miyamoto
Show Abstract
The localization of Moire fringes is studied theoretically and experimentally from the viewpoint of practical usage in Moire contouring.Introducing the concept of fringes localization verifies the phenomenon that Moire fringes do not always exist on the surface of the object. When this phenomenon is taken into considerations, the optical setup is constructed appropriately and Moire contouring reveals its validity. Some examples are presented including one application to highspeed photography.
Moire Topography As Applied To High Speed Deformation
Author(s):
Takao Tsuno;
Yoshio Nakamura
Show Abstract
This study aimed to measure high speed deformation with maximum time resolution in the range of a few microseconds. The accuracy of deformation measurement by means of Moire topography of projection type was examined on the basis of geometrical optics. As a rerult of varying the various parameters, the error was reduced by increasing the magnification and the focal length of a projection lens. Exam-ples of real-time and time-resolved Moire topography as applied for the deformation of a thin glass sheet taken by means of a high speed streak camera were presented.
Deformation Measurement By Speckle Photography
Author(s):
I. Yamaguchi;
H. Saito
Show Abstract
Speckle photography is a promising method for measuring high-speed deformation of diffuse objects. This paper deals with the effects of defocused imaging on the determination of lateral deformation. The speckle displacement in this situation has been calculated and verified by experiments.
Microvibration Measurement Using Laser Beams
Author(s):
Y. Fujimori;
T. Komatsu;
N. Hoshina
Show Abstract
A microvibration measuring apparatus for an ultrasonic welding tool was newly designed. This apparatus enabled non-contact, highly sensitive measurement free from floor vibration. It consists of a low power He-Ne laser, converging optics and a detector followed by electronic circuits. Even when horizontal floor vibration amplitude was as much as 20 μm, the minimum detectable amplitude of the apparatus was below 0.1 μm. By free vibration measurements, a 200 cps difference was found between maximum amplitude frequency and an electro-mechanical matching frequency. An amplitude output difference was found even in the same kind of welders. By vibration measurements during welding, it was found that vibration amplitude stability became worse.
Synchronization Of Laser Beams - Comparison Of Two Methods
Author(s):
G. Jean-Francois;
J. M. Bernet;
G. Lejeune;
M. Leguen;
M. Nail
Show Abstract
We have tried to develop systems permitting the 4 GHz oscilloscope TSN 660 and the picosecond chronometer TSN 637/8 to be used for the measurement of the synchronism of several neodyne laser beams of 50 to 100ps iuration. The oscilloscope TSN 660 is a laboratory instrument having been specially designed for the observation and analysis of ultra-rapid phenomena. It is fitted with a cathoderay tube including a helicoidal-type wave propagation line permitting verywideband deviation (4 GHz). Its input impedance is 50 ohms and its sensitivity 3 V/cm. The CRT output stage includes a microchannel wafer (electron multiplier) having a 104 gain. Each electron entering a channel produces on the P11 type screen of size 40 x 40 mm2, a spot sufficiently luminous to be recorded on 3000 ASA Polar-oid photographic emulsion. The trace has a thickness of 100 microns (30 mV/trace) and the highest scanning speed is 100 ps/cm, the temporal resolution is 5 ps. The multi-chronometer TSN 637/8 is intended for the measurement of time intervals among eight non-repetitive electric signals, with high resolution. Self-calibration is ensured by a microprocessor using an internal thermo-stat-controlled time master. That micro-processor carries out the correction of the measurements and a number of statistical calculations. The chronomenter is associated with input discriminator modules specially designed for the shaping of the very narrow electric pulses. The following performances are obtained: measuring range 16 ns; resolution: 1 ps; input signals: 9; thresholds adjustable from 50 to 500 mV; minimum duration: 200 ps. The use of an oscilloscope TSN 660 and of two optoelectronic switches of the AUSTON type has enabled the teams of the CEA/Limeil to synchronize through permutation, to within 10 ps, the eight beams of their COTAL laser. In conditions of correct saturation of the detectors, the total jitter is approximately 15 ps, and by carrying out a pseudo-statistical measurement with 15 experiments, the typical deviation obtained is + 5 ps. We have carried out several types of tests with the aid of the chrono-meter TSN 637/8 and by using RTC XA1003 photocells having a rise time of 150 ps, the output signal of which has been widened by means of passive dividers. We have also used ACSTON type optoelectronic switches in place of the photocells.
An Application Of Holographic Interferometry To Measurement Of Contraction Ratios Of Copper Single Crystals
Author(s):
Hiroshi Miyamoto;
Kazuo Kitagawa;
Takeshi Miyazaki
Show Abstract
According to the anisotropic elasticity theory, the contraction ratios along [110] take negative values for a number of metals when the single crystals are subjected to uniaxial forces along [110]. The pure bending tests employing holographic interferometry were conducted to confirm this phenomena using copper single crystals. In this study , the expression describing the morphology of contour lines of the anisotropic materials subjected to pure bending was presented in terms of the elastic compliances. It was suggested from this expression that, as contour lines, the positive values of contraction ratio provide hyperbolas, on the contrary, the negative values provide ellipses. The experimental results were in good agreement with the results expected analytically.
Measurement Of Crack Growth And Strain Distribution Around Crack Tip Under Elevated Temperature
Author(s):
Tatsuhiko Aizawa;
Genki Yagawa;
Yoshio Ando;
Katsuhiko Sakaue;
Mikio Takagi
Show Abstract
Through the macroscopic measurement of crack growth under the elevated temperature, the crack propagation rate has been found to be in better correlation with the J contour integral value than with other candidate parameters e.g. elastic stress intensity factor, net section stress. In order that this J value may be defined under the stationary creep condition, we must be aware of a certain singular strain field around the crack tip, which has been theoretically analyzed but the existence of which is not recognized experimentally. Using the Moire topographical method and digital processing of raw Moire grids and fringe patterns, the interesting informations have been obtained regarding the strain concentration at the crack tip.
Sonde Optique A Etages Pour La Detection Des Ecailles Enregistrement Par Fibre Optique Et Camera Electronique A Fente
Author(s):
Jean-Pierre Gauthier;
Michel Bouchu
Show Abstract
The method of hydrodynamic diagnostic discribed in the other communication we present at this congress, which uses a shock - ionized probe, a fiber optic transmission and a streak electronic camera recorder allows us to design new devices with multi-effects. We describ e an optical probe composed of ten small 0.2 mm thick spaces separated from one another by transparent glass plates 1.5 mm thick. The sweep record shows series of short flashes following exactly the moving and the pressure level of the front shock wave in the probe. The experience we are to present, shows some of the avantages of using this kind of diagnostic. The results wich are obtained with the lead plate striking the probes at a 2.5 mm//us speed show successives shocks in these multi-stages optical probes. An X-Ray experience made in the same conditions make clear that this hapvensbecause of a monaspall detached from the main plate 2 mm ahead and producing a previous shock before the main one. This method does not pretend to measure the speed of the scale, its thickness ... etc, therefore we are only looking for an accident during the target moving or not. Notice the reduced dimensions of this king of probe, the diameter of which is 4 mm, the length 20 mm and there is very easy to set up.
Nanosecond Pyrometry For The Measurement Of Thermophysical Properties Of Metals Up To The Critical Point
Author(s):
U. Seydel;
H. Wadle;
W. Fucke
Show Abstract
The fast pulse heating of metallic wires lea a conversion of the solid over the liquid into th ous state of the sample. Under certain conditionE siderable superheating of the liquid can be accon For experiments in water at atmospheric pressure ting rates >10 K/sec we obtain a thermodynamic .9 the sample close to the critical point. By applyi additional static pressure - up to 4 kbar - for c elements we even achieve a critical transition. P ratus and method for the measurement of various t physical data including the critical point of liguid metals is described. Most emphasis is put on the it tion of a multi-wavelengths pyrometer with nsec-resolution.
Measurement Of Displacements For A Cracked Body Using Moire And Photo-Interference Methods
Author(s):
Hiroshi Miyamoto;
Yasutoshi Shirota;
Masanori Kikuchi
Show Abstract
In the present work, a new method is proposed to measure the displacements in a body by using moire and photo-interference methods. This method is applied to three dimensional crack problems to obtain the state of the deformation near the crack front. Firstly, this method is applied to two dimensional crack problems to examine the accuracy of this method. Correction factors of stress intensity factors are measured and compared with theory. Good agreements are obtained. Secondly, this method is applied to a through crack problem in a thick plate. Three components of displacements are measured and their variation along the plate thickness direction are examined. The effects of the plate thickness on the singularity of crack tips are discussed.
Measurement Of Complex Elastic Modulus By Holography
Author(s):
Tsuneyoshi UYEMURA;
Yoshitaka Yamamoto;
Take shi Miyazaki
Show Abstract
This article describes a technique for measuring complex elastic modulus E* by holographic interferometry. In this technique used are the characteristics of the amplitude distribution in viscoelastic vibration which can be obtained from time-averaged holography. The dynamic elastic modulus can be evaluated from the dimensions, the density, the frequency and the distances between the positions of the maxima (or minima), and tans can be measured from the calculated relations between tans and the ratios of the minima to their neighbor maxima. By this technique, E* can be measured at the arbitrary frequency without changing the dimensions of specimen. The frequency range and the measuring range of tanδ are higher than those in conventional techniques.
Determination Of Dynamic Stress Intensity Factors Of A Glassy Polymer Using A Shadow-Optical Method
Author(s):
Kiyoshi Takahashi;
W. Doll
Show Abstract
In the present work dynamic and static mode I stress intensity factors KI of Polymethylmethacrylate were determined using a shadow-optical method in transmission. The shadow patterns under dynamic loading and during dynamic crack propagation were recorded by a high speed Cranz-Schardin spark camera. The dynamically loaded Charpy test specimens showed nonlinear oscillatory behaviour which was attributed to coupled vibrations between specimen and hammer. The values of the dynamic fracture toughness Kdyn were found to be about twice that of the static fracture toughness IcKIc stat.
The Transient Bending State Of A Transversely Struck Plate Determined By Isodensitometry
Author(s):
H. Schwieger;
V. Truppat
Show Abstract
The propagation of bending waves is visualized by the birefringent coating method. The plate to be investigated is coated by a photoelastic foil, and the dynamical photoelastic effect is studied by a reflexion-polariscope and a controlled single flash. The so called "Isodensito-metry" is applied in order to determine quantitatively the local distribution of the maximum torsional moment. The isodenses as lines of equal density are produced on the photographic film by applying the "Sabattier-Effect". In a special way the isodenses are calibrated and to-gether with other photoelastic data one is able to evalu-ate the maximum torsional moment. For getting a better in-sight into the impact problem and for verification of the optical results additional measurements of the impact forces and the strains were performed.
Rupture Behavior Of Flawed Aluminum Tube Under Internal Pressure
Author(s):
Taro Tsuyuki
Show Abstract
Aluminum tubes artificially flawed by milling to form spots of thinned-down wall were subjected at room temperature to internal water pressure, which was gradually increased until rupture at the flaw spot. The progress of crack opening at the flaw spot was observed by stroboscopy, using a drum camera with strobo-flash triggered by platinum wire stretched in front of the flaw spot. The pressure inside the tube near the flaw was monitored by semiconductor transducers. The simple trigger arrangement proved to function very satisfactorily. The time required for a crack to open to 90% of its final dimension was several tenths of a millisecond for all cases where the artificial flaw was of flat form and several milliseconds for all "pit" flaws.
An Application Of High Speed Photography To The Measurement Of Dynamic Material Properties
Author(s):
D. A. Gorham
Show Abstract
This paper describes a technique for measuring the compressive stress-strain relations of very strong materials at high rates of strain (up to 105 s-1, corresponding to test durations of a few microseconds). The specimen is a small, flat cylinder supported on an instrumented pressure bar and impacted directly by a projectile from a gas gun. High speed photography is employed to monitor specimen strain, and a simple optical component is describ-ed which greatly increases the accuracy of the records. This photographic technique also allows nonuniformities of deformation to be detected and eliminated. An accurate synchronisation technique is described, and examples of high speed sequences are included.
High Speed Photography Of Moving Domain Walls In Magnetic Bubble Materials
Author(s):
F. H . de Leeuw;
W. de Geus;
P. QJ. Nederpel
Show Abstract
Two high speed photograpy techniques for studying moving domain walls in magnetic bubble materials are given. The capabilities of both techniques are demonstrated and the advantages and disadvantages of both techniques are discussed.
Experimental Determination Of Optimum Condition For Wire Explosion In Water And PMMA
Author(s):
Toshiro Suhara;
Shigehisa Fukuda
Show Abstract
Through wire explosion in water and polymethyl-methacrylate (PMMA), electric energy stored in a condenser is converted into mechanical energy. The condition of explosion maximizing the conversion efficiency, namely the appropriate dimension (the diameter and/or the length) of wire as well as the pertinent setup of a discharge circuit, has been determined experimentally.
Holographic Measurements Of Velocity Distribution Of Particles Accelerated By A Shock Wave
Author(s):
T. Murakami;
M. Ishikawa
Show Abstract
A new holographic technique to measure the size and velocities of fine particles has been developed. The two lasers of different wave length are set up in the same optical axis, and fired at an interval of few micro seconds. The two output beams with inline holographic information of the object particles are separated by a beam splitting cube and two interference filters, then the holograms of moving particle system at the different instants are recorded on the two films separately. These two holograms are super-imposed each other and the moving distances of particles are measured microscopically. This new technique is applied to observe the distribution of particle velocities induced by a shock wave.
High-Speed Photography And Holography Of Laser Induced Breakdown In Liquids
Author(s):
Werner Lauterborn
Show Abstract
Optical breakdown phenomena in liquids due to focused ruby laser light are investigated by high-speed photograph: and holography. Special attention is given the dynamics of the cavities produced in the liquid upon breakdown as they can be expected to become a powerful research tool in cavitation physics. To this end the production of threedimensional breakdown configurations would be desirable as well as their investigation by high-speed holographic means. Both problems are presently under study. To achieve multiple breakdown at preselected points in the liquid a grating - lens assembly and digital holograms in photore-sist are used. To film the motion of the cavities high-speed holocinematographic methods are developed. By now four to eight holograms can be taken at a rate of 10 to 20 kHz.
The Application Of Holography To The Comparison Of Grinding Wheels
Author(s):
S . H. Salem;
J. K. Russell
Show Abstract
Holographic interferometry was used to determine the static deflection of grinding wheels. All limitations imposed on the experiment by the nature of the grinding wheel were overcome. The elastic movement of the structure of different grinding wheels was identified. The displacement was calculated for various wheels using the resultant fringe pattern.
High Speed Holography Relaxing The Restriction On Object Velocity
Author(s):
T. Sato;
K. Murata;
H. Fujiwara
Show Abstract
In high speed holography the motion of an object during the exposure causes a modulation of the interference pattern to be recorded on a hologram plate. Therefore the velocity of an object is limited. This limitation on the allowable velocity of a moving object can be relaxed by the use of a frequency chirp of the laser pulse. The applicability of this principle is examined experimentally. The result shows that limited velocity increases several times. Furthermore, employing a new arrangement similar to Michelson interferometer, a two-frequency holography is simulated for high speed objects. This arrangement is applied to a holography of a balloon breaking.
Application Of Pulse Laser Holography
Author(s):
Tsuneyoshi Uyemura;
Yoshitaka Yamamoto;
Koji Tenjinbayashi
Show Abstract
Using a pulse laser holography method, it is possible to record moving objects in three dimensions. Furthermore when a double pulse light source is obtained, it is possible to perform the double pulse holography, and various high speed phenomena can be investigated. We could get a double pulse from doubly Q-switched ruby laser and made two kinds of double pulse holograms, and showed the utility of double pulse holography method.
Ultra High Speed Real-Time Holographic Interferometry
Author(s):
T. Uyemura;
Y . Yamamoto;
N . Yokoyama;
S. Tochiori
Show Abstract
This article describes the observation system consisted of real-time holographic interferometry and ultra high speed camera. In order to use ultra high speed camera as recording camera in real-time holographic interferometry, we have to conquer some obstacles such as low quantity of light , synchronization and so on. To examine the validity of using ultra high speed cameras in real-time holographic interferometry, we performed an experiment so that we could record the explosive combustion of butane gas by the system at the framing speed of 60,000 fs/s with Uyemura's MLD-2 ultra high speed camera.
Recording Of Three-Dimensional Trajectories Of Solid Objects
Author(s):
T. Tschudi;
F. Heiniger;
G. Indebetouw
Show Abstract
Holographic and stereoscopic methods to record the three-dimensional, time-resolved trajectory of solid objects are investigated. Spatial resolutions of the order of 100 pm and time-resolution in the nanosec range were achieved. The methods could find applications in the field of mechanics (machine control), medicine and dentistry (design of protheses).
High Speed Laser Interferometric Framing
Author(s):
G. E.A. Meier;
W. J. Hiller
Show Abstract
A laser with acousto-optic output coupler can be used in high speed framing as a high frequency light source with short flash duration. No special devices for producing standing images on the film in the camera are needed. All types of optical arrangements can be used with the repetitive light source. A cold supersonic jet in a hot gas mantle was inves-tigated using a differential interferometric technique. A holographic real-time interferometer was used for the visualization of thermal convection.
Dynamic Laser Speckle Interferometry Applied To Wave Propagation In Solids
Author(s):
F. P. Chiang
Show Abstract
When an optically rough surface is illuminated by a laser beam, multiple scattering results in a random inter-pattern called speckles. When these are recorded by double exposure before and after deformation of the surface, interference fringes are obtained upon optical Fourier filtering of the photographic record, and they are indicative of the speckles' spatial displacements. This pheno-menon is exploited in the paper to map stress waves in plates due to transverse and in-plane impact loading. The method of differential speckle interferometry is also introduced which is capable of mapping the particle velocity field of the plate.
Time-Resolved Holographic Record Of Phase And Intensity Ripples In High Power Laser Emissions.
Author(s):
German DaCosta
Show Abstract
Statistical distributions of phase and intensity of light in the free-running emission of a ruby laser working well above the oscillation threshold are studied using a incoherent holographic technique. It is shown that a coherent speckle pattern is emitted in each spike, and also, in certain conditions, in the integrated emission. It is inferred that free-running ruby lasers can be used to extend recently-developed speckle interferometric techniques to the microsecond time domain.
Measurement Of Masses Of Fragments In Flight By Flash Radiography
Author(s):
Francis Jamet
Show Abstract
Let us suppose that a parallel beam of X-rays passes through an homogeneous fragment. The absorbing thickness along a ray is obtained by comparing the value of the optical density corresponding to this ray with the optical densities generated by a calibration step of the same material as the object. The integration of the thicknesses over the whole surface of the image of the object leads to the knowledge of the volume and mass of the fragment.
Flash X-Ray Diffraction Study During Shock-Compression
Author(s):
K. Kondo;
A. Sawaoka;
S. Saito
Show Abstract
Flash X-ray diffraction (FXD) study was performed during shock-compression by using the Blumlein FX source and an image intensifier. The dimension of this Blumlein body is approximately 6 m in length and 0.2 m in diameter. The electric pulse is 80 nsec wide but the real X-ray pulse is estimated to have a width of a few 10 nsec. The optimum condition of electrode dimensions for X-ray radiation was determined. The delay and jitter to trigger the FX source were also determined to synchronize the X-ray pulse pre-cisely with the arrival of the shock front. FXD patterns of LiF during shock-compression have been obtained up to 50 GPa.
Flash Radiographic Observation Of Shock Wave Propagation In Solids
Author(s):
Kunihito Nagayama;
Masahiro Fujita;
Ikuo Ohkawa;
Kenkichi Kiyota
Show Abstract
Flash radiographic method has been used to observe the propagation of plane shock waves in solids, particularly in laminated composites. Preliminary experiments on PMMA sample shows that the method is useful for determining the shock wave parameters in condensed media. Then the method has been applied to composite samples consisting of alternate layers of PMMA and aluminium. A plane shock wave was transferred to these bi-laminar system parallel to the laminations. The shock front in each PMMA plate was observed to be slightly curved because of the impedance mismatch between constituents. Across the shock front, an abrupt change in area ratio of constituents was also observed. The average Hugoniot data obtained for laminated composites have been compared with previous theoretical models.
Laser Fusion Experiment On Pellet Implosion Observed By X-Ray Streak Photography
Author(s):
T. Sasaki;
H. Azechi;
K. Aono;
T. Yamanaka;
K. Hosokawa;
K. Nishihara;
C. Yamanaka
Show Abstract
We have investigated the characteristics of a transmission type x-ray streak camera and performed the measurement of implosion process of laser fusion plasma with this camera. The streak tube contained two channel plates inside to obtain a higher sensitivity. The maximum sweep speed was 1.5 mm/sec and the time resolution was es-timated to be approximately 15 ps. The implosion time and velocities of glass microballoon plasma produced by "Gekko II" two beam glas, laser system were measured and were about 475 psec, ~10 7cm/sec, respectively. These results were agreed well with the results of plasma simulations in which one dimensional, one fluid and one temperature model were used.
X-Ray Flash And Acoustoelectric Studies On Compression Rings
Author(s):
R. Germer;
O. Luhrs
Show Abstract
Spark discharges in thin layers of liquid between solid electrode plates produce compression rings due to interaction of different shock waves. The waves are detected with fast microphones. Small piezoelectric ceramic indicators are used 40-350 mm distant from the discharge. For the nearer surrounding magnetostrictive microphones with acoustic delay lines of glass have been constructed. The shock wave interaction depends on the sound velocities of liquid and elec-trode plates as well as on the thickness of the plates. These influences are measured with X-ray flashes. The experimental data are interpolated to obtain the time and place of shock wave interaction. These investigations lead to a more de-tailed knowledge of shock and head wave interactions near spark discharges.
X-ray Cinematography on the Nuclear Fuel and cladding Motion Diagnostics
Author(s):
Hiroshi Mizuta;
Shinichi Uruwashi
Show Abstract
X-ray cinematography has been used for monitoring fuel motion in the out-of-pile fuel pin joule melting experiments for nuclear, liquid metal cooled fast breeder reactor, safety studies related to fuel pin failure, initial fuel motion and thermal fuel-coolant interaction (FCI) of the hypothetical core distractive accident. In order to visually observe the nuclear fuel motion, the X-ray cinematography system consists of an X-ray source located about 5 cm from the test section and an image intenfifier located at a corresponding position on the opposite side of the test section. The image from the image intensifier has been recorded both with a high speed camera and video recorder.
Comparison Of High Speed Movie And Flash X-Ray Measurement Of The Translational And Rotational Motions Of Projectiles Penetrating Gelatin
Author(s):
Eugene T. Roecker
Show Abstract
Projectiles penetrating a gelatin block were simultaneously mea-sured by a high speed movie camera, Dynafax, and by a sequential, orthogonal, flash x-ray system. The eight orthogonal views of the x-ray system provided position and orientation of the projectiles vs, time From onset of tumble in the gelatin, owing to gyroscopic in-stability, the growth of yaw was the same for each round in a re-plicated set. This phenomenon provided a legitimate procedure for pooling the x-ray data, giving well determined curves of velocity decay and yaw growth. The movie camera observed the progress of the cavity formed by the projectile. The resulting velocity decay of the cavity tip was compared to that of the projectile as measured by the x-ray technique.
The Status Of Flash Radiography In The U.S.A. Today And Future Possibilities
Author(s):
L. Bryant
Show Abstract
A sample of presently employed flash x-ray generators is given including low-energy, commercially available systems and high-energy very specialized installations in government laboratories. These flash x-ray sources are compared as to radiographic characteristics. Imaging techniques and materials are surveyed and compared as to their advantages and limitations. A variety of applications of flash radiography are cited including explosive, ballistic, diffraction, crash injury, and fuel injection. Probable near term advances in special techniques are mentioned in cine radiography and film image enhancement. Possible future developments are speculated upon such as flash radiographic applications of computerized axial tomography. The recent recognition of flash radiography at professional society conferences is reviewed.
Some New Possibilities In Direct Visible And X Ray Measurements
Author(s):
J. P. Gex;
R. Sauneuf;
J. P. Boutot;
J . C. Delmotte
Show Abstract
Subnanosecond photodetection measurements in visible and X ray range with vacuum cell and very thin microchannel plate phototube (coupled with a fast scintillator or not) in conjunction with fast oscilloscope (5 GHz) are presented. They are compared to those given by a visible or a gold photocathode X-ray streak camera (temporal resolution better than 20 ps).
A New Low-Impedance High-Intensity Flash Soft X-Ray Machine
Author(s):
Peter Krehl
Show Abstract
A compact high-intensity flash soft x-ray machine in the nanosecond time region for shadowgraph applications in low-density matter as well as flash x-ray diffraction is described. The pulser consists of several 100 kV low-impedance coaxial pulse cables with the cable ends connected together to form closed loops. The pulser impedance can be varied stepwise between 6.7 and 0.67 0 by increasing the number of loops from one to ten. This new technique facilitates appropriate tai-loring of the anode-cathode geometry and opens the possibility for streak radiography when using long cables. Initial flash x-ray diffraction tests on a polycrystalline copper foil demonstrate the enhanced x-ray output relative to other machines.
High-Speed Radiography And X-Ray Cinematography By High-Current Betatrons
Author(s):
Yu. V. Akiniochkin;
G. V. Akulov;
F. G. Leunov;
V. A. Moskalev;
V. L. Ryabukhin;
Yu. M. Skvortsov;
V. V. Shasaov;
V. G. Shestakov
Show Abstract
The paper provides a description of an equipment system comprising a pair of 25 MeV high-current betatrons and an X-ray drum-type cinecamera for high-speed radio-graphy and X-ray cinematography for use when studying dynamics of objects moving at a rate of 0.5-3.0 km/s as well as in X-ray cinematography of processes at a rate of up to 1 m/s.
X-Ray Imaging By Penumbral Reconstruction
Author(s):
G. B. Gillman;
I. D. G. MaCLeod
Show Abstract
The conventional X-ray pinhole camera is limited to about 3 μm resolution at 10 keV due to manufacturing limitations. A new imaging technique, which is based on recovering information about the source from penumbral shadows, is expected to resolve to the diffraction limit. Examples of the reconstruction of simulated source intensities by different methods are presented. Geometrical considerations of a practical system are discussed.
X-Ray Image Intensifiers For High-Speed Cineradiography
Author(s):
B. Driard
Show Abstract
Our understanding of the behavior of rapidly evolving or moving bodies has been advanced considerably by the use of high-speed cine-photography. This technique is concerned essentially with the exter-nal aspect of the bodief or with associated luminous phenomena. The internal structure or behavior of bodies that are opaque to visible light can be investigated by means of X-rays.These two techniques can be combined by using fast-response X-ray image-intensifier tubes. These two techniques which incorporate phosphors having a very short response time (about 0.25 µs), permit forming X-ray images obtained with pulsed energies of 50 keV to several MeV at frequencies of up to 106 images per second.
Expression De La Resolution D'une Image Radiographique Par Une Formule Simple
Author(s):
Guy Bourdarot
Show Abstract
We propose to set in an easy formular every element of an X-Ray device : - X-Ray source, - X-Rayed body, - The receipt apparatus. We are then obliged to set a nomber of simplifying hypothesis : - The radiation energy is the same for every calculation, - The source is supposed to be pin-pointed and isotropic. To caracterize the details at the level of the X-Rayed object we introduce the notion of "object contrast". The reception system is defined by a gain conversion which expresses the probability of an X-photon unabsorbed by the body, proving at least one recorded event. Statistical considerations allow us to calculate the minimum surface of the detail to identify must have. This minimum, inverse resolution of the whole X-Ray apparatus, varies according to the number of photons provided by the source, the way the object modulates the beam, and the conversion gain of the reception system. For exemple, at a given energy - we can show that the resolution is maximum when this object has an optical thickness twice the mean pathlength of the radiation.
High-Energy Cine-Radiographic Experiment
Author(s):
L. Bryant;
B. Craig;
A. Lundy;
W. Morton
Show Abstract
A cine radiographic technique is being developed by using an inert rocket motor to simulate a burning rocket motor. Because of radiation attenuation in the object and safety considerations for the equipment in an actual test, a high-energy, high-intensity x-ray source was chosen. The source is a 10-MeV linear accelerator with an output of up to 2,500 R/minute at 1 m and a maximum pulse repetition rate of 240/s. Various fluorescent intensifying converter screens are being evaluated. The image from the screen is amplified electronically and recorded on a high-speed camera. This camera gives an output signal which synchronizes the linear accelerator pulse with the camera frame. The images obtained thus far are only crude representations of a resolution gage and a thickness gage superimposed on the object image.
Designing Principles And Dynamic Tests Of Picosecond Image-Converter Cameras
Author(s):
V. I. Lozovoi;
v. E. Postovalov;
A. M. Prokhorov;
Yu. N. Serduchenko;
M. Ya. Schelev
Show Abstract
Basic requirements imposed on image-converter tubes (ICT) and pulsed control circuitry intended for construc-tion of reliable image-converter camera (ICC) are briefly discussed. One of the prototype of the EOK-2 portable picosecond camera developed for laser and laser plasma diagnostics is exhibited. In order to proceed many kinds of dynamic tests three different types of Nd-glass and YAG lasers are employed. The camera temporal resolution and dynamic range are established by recording of mode-beats and single pulse laser radiation with prcisely known values. At a maximum streak spead of 2.2 109cm/s the camera provides temporal resolution of lOps at dynamic range of about 30.
Characterization Of Image Converter Tubes And Photodiodes In The Infrared Region
Author(s):
N. Fleurot;
M Nail;
R. Verrecchia;
G. Clement
Show Abstract
The detection of near infrared picosecond luminous events is of the highest interest in the laser fusion research. The temporal profile of the 1.06 μm laser pulse, has to be carefully measured with SI streak cameras which present limitations in the picosecond range. We have undertaken measurement on Si photodiodes to situate their fatigue threshold and try to understand the limitations of image converter tubes.we also present the work undertaken at R.T.C./L.E.P. to produce stable and highly sensitive image converter tubes in the micron range with the "transfer sensitization method".
Picosecond Chronoscopy Of Repetitive Weak Light Sources Using The Synchroscan System
Author(s):
R. Hadland;
K. Helbrough;
A . E. Huston;
M. C. Adams;
W. Sibbett;
M. M. Salour
Show Abstract
A picosecond streak camera which operates at a repetition rate of 140 MHz in synchronism with a CW mode-locked laser is described. Experi-mental results are presented which indicate that the SYNCHROSCAN system at present has a temporal resolution ≈ 1Opsec and the possibility of improving this resolution;Opsec is discussed. SYNCHROSCAN has been built into a commercially available camera (IIIACON 675) and a temporal resolution ⪅2Opsec demonstrated in this form.
Framing-Camera Tube Development for the Sub-100-ps Range
Author(s):
Ralph Kalibjian;
Lamar W. Coleman
Show Abstract
A new framing-camera tube is capable of recording two-dimensional image frames with high spatial resolution in the sub-100-ps range. Framing is performed by streaking a two-dimensional electron image across narrow slits; the resulting electron line images from the slits are restored into a framed image by a restorer deflector operating synchronously with the dissector deflector. Performance has been demonstrated in a prototype tube by recording 125-ps-duration framed images of 2.5-mm patterns. The limitation in the framing speed is in the external electronic drivers for the deflectors and not in the tube design-characteristics. Shorter frame durations (below 100 ps) can be obtained by use of faster deflection drivers.
Optimized Electron-Optical Computations Of Image Tube Designs For High Temporal Resolution Chronoscopy
Author(s):
D. J. Bradley;
K . W. Jones;
W. Sibbett
Show Abstract
A computer programme has been developed for electron-optical design taking into account the effects of time-dispersion in photoelectron trajectories. Starting with a particular eledtrode-arrangement, the potential destributions are first plotted and visually displayed. Improvement, or otherwise, in time and spatial resolutions arising from new electrode arrangements are then readily computed and displayed. Skew trajectories are included in the computations:
Computer Evaluation Of Images Taken With Picosecond Image-Converter Cameras
Author(s):
N. S. Vorob'ev;
V. P. Degtyareva;
Y . N. Platonov;
A. M. Prokhorov;
Yu P. Pyt'eit;
M. YA. Schelicv
Show Abstract
Estimation of image parameters will be given for pictures taken with picosecond image-converter cameras (ICC). Mathematical approach to the modulation transfer and spread functions, dynamic range region,spatial and temporal resolution is discussed. On the basis of statistical evaluation theory and taking into account the streak tube spread function some examples of image parameters evaluation are presented.
Analysis Of The Performances Of A New Picosecond Streak Camera (TSN 505)
Author(s):
G. Jean-Fradicois;
N. Fleurot
Show Abstract
That camera has been developed for the study of the phenomena related to the laser-matter interaction experimentation. It is fitted with a deflected-type shutter tube including a multichannel wafer (electron multiplier) which increases the photon gain in a ration of 103. The following experimental system is used to measure the characteristics of the camera:
Two Special Purpose Cameras Using Microchannel-Plate Intensifiers
Author(s):
J. Hadland;
K.A. F . Haynes;
K. Helbrough;
A. E Huston
Show Abstract
A camera for surveillance purposes uses a microchannel-plate intensifier tube and motorised film transport system in a design which permits direct viewing of the intensifier screen via a biocular magnifier, combined with photography by direct contact of film on the fibre-optic output plate of the intensifier. Automatic gain circuits compensate for both subject brightness and exposure duration, so that correct exposure of the film is obtained without manual adjustment. Exposures from 1/10th to 1/3,000th sec. are available. A camera for projectile photography makes use of a system of multiple pulse gating of the microchannel-plate inten-sifier tube. The multiple gating enables high cut-off ratio ( 107) to be obtained. Exposure duration can be set from 100 ns to 10 us.
Picosecond Streak Camera With A Lamellar Optics Image Converter Tube
Author(s):
B. Boutry;
C. Delmare;
N . Fleurot
Show Abstract
The development of new generations of impe converter tubes (I.C.T.) has been undertaken by C.E.A. and L.E.P. to achieve pico-second time resolution with streak cameras (Picoscope tube microchannel integrated P500 F tube). A new lamellar tube (P 600) designed by L.E.P. has been coupled to a streak camera, driven by a laser triggered spark gap constructed by C.E.L. Here we present the first performances obtained with this camera.
Dynamic Range Studies Of The RCA Streak Tube In The LLL Streak Camera
Author(s):
S. W. Thomas;
G. E. Phillips
Show Abstract
As indicated by tests on several cameras, the dynamic range of the Lawrence Livermore Laboratory streak-camera system appears to be about two orders of magnitude greater than those reported for other systems for 10- to 200-ps pulses. The lack of a fine mesh grid in the RCA streak tube used in these cameras probably contributes to a lower system dynamic noise and therefore raises the dynamic range. A developmental tube with a mesh grid was tested and supports this conjecture. Order-of-magnitude variations in input slit width do not affect the spot size on the phosphor or the dynamic range of the RCA tube.
Performance And Application Of Photochron Streak Cameras
Author(s):
S. F. Bryant;
J. R. Taylor;
W. Sibbett;
D. J. Bradley
Show Abstract
The "time-resolution limited (TRL) dynamic range" of operation of Photochron picosecond streak cameras is shown to depend upon the time-resolution employed. Using photographic recording for events r,2 ps a TRL dynamic range of 30 is obtainable before appreciable time-resolution is lost and this increases to a value of 180 for 35 ps events. No accumulative saturation effects occur at a time resolution as short as 2 ps. By replacing film by an optical multichannel analyser (OMA) the camera TRL dynamic range was increased to ~ 150 for 4 ps events.
The Weizmann Institute Modular Image Converter Streak Camera
Author(s):
L. Diamant;
I . Plesser;
D Bernstein
Show Abstract
The Modular Image Converter Streak Camera of the bfeizmann Institute of Science was built according to the previously reported design 1) . Tests of streak linearity, jitter and dynamic range were carried out. A novel technique, employing the sweep of a fast oscilloscope beam was used for determining both streak linearity and absolute calibration. Two new multistreak plug-in modules were built: a Krytron based low jitter module for 50/100/200 ns sweep time and Krytron/transistor module for 1/3/10/30 ps sweep. Technical details and testing results are presented. The camera has been used in experiments on the self pinching effects of an intense electron beam, where its usefulness and convenience as a research tool were demonstrated.
Electron-Optical Device For High Speed Registration Of A Nanosecond Pulse Coherent Radiation Wavelength In A Wide Spectral Range
Author(s):
Yu. A. Drozbin;
V. E. Prokopenko;
L. A. Rass;
B. M. Stepanov
Show Abstract
A device for high speed measurement of the absolute value of the pulse radiation wavelength instant quantity in the spectral range of 0.34+0.8 mcm is described. The duration of the shortest radiation pulses under investi-gation is about 50 ns with the pulse repetition rate of 0+10 c/s. The device may also be used for the measurement of continuous laser radiation wavelength. When radiation divergence is 2.10-2 rad the radiation energy at the de-vice input gt the wavelength of λ =0.63 mcm does not ex-ceed 40.10-6J.Radiation wavelength measurement error is 10-2 Å.
Method Of Electron-Optical Chronography For Investigation Of Photonica In Photochromic Materials
Author(s):
V. A. Barachevsky;
S. G. Kuzmin;
B. F. Mandzhikov
Show Abstract
The method of laser photoexcitation with registering spectral changes on the screen of an image-converter tube to study some primary phototransformations in photochromic spyropyranes in liquid and solid polymeric solutions has been used for the first time. The scheme of the device providing for the registrations of the absorption and luminescence spectra in the 400 to 750 nm band with time resolution up to IO-II s is presented. The results of the investigations show the polymeric matrix to have some specific effects upon the photocolouration of spyropyranes.
Picosecond Dynamic Measurements Of X-Ray Image Converter Tubes
Author(s):
G. I. Bryukkhnevich;
E. I. Zak;
A. V. Kil'Pio;
A. F. Klyepov;
L. I. Kondrashova;
A. A. Malyutin;
V. A. Miller;
A. M. Prokhorov;
B. M. Stepanov;
T. I. Ushakova
Show Abstract
Some characteristics of the new type of X-ray sen-sitive image converter tubes are given. These tubes are single-stage image-converters designed on the base of the UMI-93 SR's time analyzing stage. Special attention is paid to the problem of the dynamic measurements. Using picosecond laser produced plasma the minimum X-ray pulse duration of 12 Ps is measured.
Developments In The Use Of Image Intensifiers In Cineradiography
Author(s):
S Cross;
A . E. Huston
Show Abstract
At the 12th Congress in 1976 a paper was 1'resented describ-ing a system. for cineradiography with continuous x-ray sources, which made use of a gated intensifier tube and a rotating prism high-speed. camera. The system has been further developed, and put to practical use in recording of passage of shot from a gun, pouring of castings, deformations in pneumatic tyres and penetration of materials by projectiles.
Electrooptic Deflector Design Considerations For Use In The Crystal Streak Camera
Author(s):
S. W. Thomas
Show Abstract
Figure-of-merit equations for material selection and detailed design equations have been developed to aid in the design of a linear electrooptic deflector element for use in a 10-ps streak camera. The figure of merit indicates that BaTiO3, KTN, and ammonium oxalate (AMO) are suitable materials. Possible deflector designs, including that of a current AMO prototype development program, are discussed. Quadratic (Kerr-effect) operation and materials are discussed along with the possibility for 10.6-μm-wavelength use.
Streak Tube With Microchannel Plate
Author(s):
K. Kinoshita;
Y Suzuki
Show Abstract
A streak tube with microchannel plate has been developed. This new tube has enabled to make the streak camera simple and compact. The light amplification factor of the tube is larger than 104 and the limiting time resolution is ≤2 ps.
Recent Technical Developments And Intensification System Studies With The LLL Streak Camera
Author(s):
G. E. Phillips;
S. W. Thomas
Show Abstract
Experiments verify that spectral matching factors for cathodes and phosphors can be used successfully to predict the important "film gain" for image intensifiers used in streak cameras when the luminous or other gains are known. A Pll spectral source made from filters and a white light source allows a simple Pll gain measurement to be made. This measurement is useful for direct calculation of film gain, independent of intensifier cathode spectral variations. Because of lower noise, proximity focused microchannel intensifiers have a definite advantage over electrostatic and magnetically focused intensifiers for streak-camera use. Other developments are discussed.
Picosecond Time-Resolved Interferometric Streak Unit
Author(s):
T. Honda
Show Abstract
An optical deflection interferometric streak system has been studied for measuring picosecond optical pulses from mode-locked lasers. The interferometric streak unit consists of high speed electro-optic deflectors installed in the two-beam interferometer. Preliminary experiments on a prototype system indicates that the interferometric streak unit has the possibilities of improving time resolu-tion of conventional electronic streak cameras and developing a new picosecond time resolved interferometric streak camera. The time resolution of 100 ps can be obtained with an electronic streak camera of the spatial resolution of 2.5 line pair/mm, which is used for testing the system at a 1.064 µm wavelength.
Ultrafast Streak Camera
Author(s):
Y Tsuchiya;
E Inuzuka;
Y. Suzuki;
W. Yu
Show Abstract
A. high precision, high reliable and compact streak camera allowing easy operation, based upon a newly developed streak tube with the inclusion of a microchannel plate as an electron image intensifier and a deflecting circuit using avalanche transistors, has been developed. This streak. camera has demonstrated, good qualities of dy namic spatial resolution of about 7 1p/mm at the output phosphor screen, and temporal resolution of better than 10 ps (FWHM) in a linear dynamic range of better than 100:1 at relatively small time jitter of about 50 ps under the combined. system with a automatic streak data acquisition system.
Proximity-Focus: The New Generation Streak Tube
Author(s):
Albert Lieber
Show Abstract
A new era in x-ray and visible streak photography opened with the introduction of the proximity-focus or planar streak tube. Elimination of grids and photoelectron pinhole optics has resulted in a tube capable of transmitting peak photoelectron currents neces-sary for recording picosecond and sub-picosecond events without temporal or spatial distortion. Vacuum compatible x-ray cameras, based upon the planar design, have demonstrated better than 3 ps resolution. Visible cameras have shown impressive dynamic range and produced streaks of high statistical quality with picosecond resol-ution. These properties have opened new fields in picosecond and sub-picosecond photography.
A New Versatile Picosecond Streak Camera
Author(s):
A. E. Huston;
K. Helbrough
Show Abstract
To be commercially viable, a picosecond streak camera design must be sufficiently versatile to accept a variety of streak tubes, inten-sifier tubes, electronic circuit systems, etc., without difficulty, and a new camera has been developed with this feature as a major aim. A component part of this is a film transport mechanism which accepts standard 35mm cassettes, but may be operated at potentials up to 20 Kv above ground; this permits various intensifier tubes to be used, with their cathodes at ground potential, and with the film in contact with the fibre-optic screen face-plate of the tube. The SYNCHROSCAN system, enabling repetitive weak light sources to be recorded on a picosecond time scale, is one of the electronic options available with the camera.
Deviateur Angulaire Electro-Optique Ultra-Rapide Fonctionnant A La Nanoseconde - Applications
Author(s):
M. Blanchet;
J. C Dupont;
E. DE Bazelaire;
J. P Chambaret;
M. Franco
Show Abstract
An angular deflector consisting of a set of electro-optical prisms immersed in an index fluid operating in the vicinity of Curie temperature has been devised. This device makes it possible to obtain a deflection of one degree at the angular speed of one degree per nanosecond with a dynamic resolution of the order of 25 points.
Picosecond High Power Laser Systems And Picosecond Diagnostic Technique In Laser Produced Plasma
Author(s):
Hiroto Kitroda;
Hrutake Masuko;
Shigeru Maekawa;
Yoshiji Suzuki;
Masaru Sugiyama;
Eiji Inuzuka
Show Abstract
Highly repetitive, high power YAG and Glass laser systems have been developed and been successfully used for the studies of laser-plasma interactions. Various picosecond diagnostic techniques have been developed for sudh purposes in the regions from optical to X-ray frequency. Recently highly sensitive X-ray (1 - 10KeV) streak camera for highly repetitive operations have been developed. Preliminary experiment shows the achievement of 28ps temporal resolution (100μm slit) and good sensitivety with detectable minimum number of 10E3-1KeVphotons/shot/slit area.
Picosecond Microphotography Of Laser-Plasma
Author(s):
H. Azechi;
S. Oda;
T. Sasaki;
T. Yamanaka;
C. Yamanaka
Show Abstract
Picosecond microscopic photography with high spatial-and temporal-resolutions was applied to the investigation of laser-produced plasmas. An interferometer with resolutions of 2 µm and 20 psec was developed for measuring plasma density. Shock waves propagating inside targets and plasma density profile were observed. It is pointed out that spatial nonuniformity of the laser light produces nonuniform acceleration in the hydrodynamic motion. Density profile indicates strong steepening pushed by intense radiation pressure.
High Speed Manyframe Optical Methods For Plasma Diagnostics
Author(s):
A. A. Erokhin;
A. S. Shikanov;
G. V. Sklizkov;
Yu. A. Zakharenkov;
N. N. Zorev
Show Abstract
A complex of active optical plasma and strong ionized shock wave diagnostics is described. The complex consisted of a specially developed high speed manyframe systems of shadow, schlieren and interferometric photography. The comparison of results obtained by a simultaneous registration of investigated object by means of different optical methods allowed us to determine optimal employment range for the methods. The sensitivity, temporal and space resolution of each optical method under conditions of high probe ra-diation refraction are discussed. The application boundaries of these methods for ionized shock wave investigation were found to depend on the shock wave front width.The methods described were used for the study of laser-produced plasma phenomena, occuring in the experiments on powerful nine-channel laser installation "Kalmar".
Time And Wavelength Resolution Of Transient Plasmas
Author(s):
Serge Prohuroff
Show Abstract
The inverse integral transforms, as Abel's transform, do not fit to plasma diagnostic of badly reproduceable spectral recordings. A method is developed which allows the correct interpretation of emission spectra, based on extremely reduced numerical treatement of the expe rimental data. The procedure requires spectral data of types as different as absolute intensities, line shapes or line shifts, that may be concentrated in narrow wavelength bands or very distant from each other. Therefrom the need for multichannel devices, which are presented here. Physical reasonable interpretations are proposed in terms of some thermodynamic variables.
Picosecond Streak Camera Diagnostics Of C0[sub]2[/sub] Laser-Produced Plasmas
Author(s):
P. A . Jaanimagi;
R. S. Marjoribanks;
R. W. Sancton;
G. D. Enright;
M. C. Richardson
Show Abstract
The interaction of intense laser radiation with solid targets is currently of considerable interest in laser fusion studies. Its understanding requires temporal knowledge of both laser and plasma parameters on a pico-second time scale. In this paper we describe the progress we have recently made in analysing, with picosecond time resolution, various features of intense nanosecond CO2 laser pulse interaction experiments. An infrared upconversion scheme, having linear response and <20 ps temporal resolution, has been utilized to characterise the 10 μm laser pulse. Various features of the interaction have been studied with the aid of pico-second IR and x-ray streak cameras. These include the temporal and spatial characteristics of high harmonic emission from the plasma, and the temporal development of the x-ray continuum spectrum.
Use Of An Image Converter Camera For The Magnetio-Optical Spectroscopy Of Solids In Pulsed Ultra-High Magnetic Fields
Author(s):
G. Kido;
N. Miura;
S. Chikazumi
Show Abstract
A time resolving optical spectrometer was constructed using an image converter camera. The spectrometer was successfully employed for obtaining the Faraday rotation spectra and Zeeman splitting of absorption lines in pulsed ultra-high magnetic fields. The ultra-high magnetic fields are generated by compressing magnetic flux with an electromag-netically accelerated metaL ring. The maximum field reaches 2.8 MG (or 280 T) in approximately 3 µs. A motion of the squeezing rings was also observed by the image converter camera.
Instant Computing Of The Spatial Distribution Of Intensity In Picosecond Laser Pulses
Author(s):
L. A. Lompre;
G. Mainfray;
J. Thebault
Show Abstract
One TV-camera associated with a 64 K bytes digital memory. and a 8080 Microprocessor allows the treatment in real time of the spatial distribution of intensity in a single picosecond laser pulse used in multiphotonic experiments at 1 µ 06 wavelength. The silicon mosaic pickup tube employed for imaging is preilluminated for 200 isec before the arrival of the laser pulse in order to improve the linearity. The system is able to record 256 x 256 image elements and 256 amplitude levels. At present the number of significant levels is 64 but routine work is carried out using 32 levels, with color display of each amplitude level, and 5 seconds computations of the relative intensity value in a cross section of the beam.
Estimation Of Limiting Possibilities For Image Recording
Author(s):
V. M. Epimov;
A. M. Iskoldski;
Yu. E. Nesterikhin
Show Abstract
A model for image recording is considered taking into account the errors caused by object light field fluctuations, light signal transformation to a random photo-count sequence in the detector, unverse transformation of this sequence to a continuous signal by a reader.
A Digital Time Encoding Device For A High Speed Cine Camera
Author(s):
P. W.W. Fuller
Show Abstract
A common problem when filming short duration events with high speed cine cameras is that of identifying the event in terms of the time elapsed from a given start time. Several systems have been evolved whereby timing marks are printed onto the film at regular intervals. However, their appearance is not related directly to the film frames and identification of a frame and its time of exposure from a given datum requires a great deal of interpretation. The scale of the problem may be seen for example where in say 100 feet of exposed film only a few feet may contain relevant information. A convenient solution would be to uniquely identify each individual frame. This requirement is complicated by the fact that the film speed through the camera gate changes as the camera runs up to operating speed. The device described encodes each individual film frame and also makes allowance for instantaneous film speed.
A Partial Solution To The Fourth Dimension Problem In Digital Data Reduction--Turnaround Time
Author(s):
David M. Stern
Show Abstract
There is a need to provide a photo-optical digitizer system to ascertain quickly and accurately, the information required. Many quantitative measurements must also be recorded, compared, stored, and computed in real time. The best feasible solution is a semi-automatic system with an open-end output capability, able to digitize the information. The L-W International 110-C Photo-Optical Digitizer System, the "Informer," could solve the dilema. The system will accept an image from projectors with various a-perture formats, television monitors, and hard copy. The Digitizer provides for lengths, areas, angles, frame count, and other various features. After digitizing, data can be transmitted to computer peripherals and major computer systems. The "Informer" has a standard EIA-RS232C or Bit Parallel output interface or optional special interfaces.
Development Of A High-Speed TV Digitizer
Author(s):
H. Shimoda;
I. Fujitaka;
T. Sakata;
K. Fukue
Show Abstract
A high-speed TV digitizing system was developed. It consists of a high-resolution vidicon camera, a read-out controller, a video densitometer which is an A/D conversion unit (VDM), a video RAM and its controller, and a shading correction system. Control command bus lines connect the CPU (HP 2113-E), TV camera, read-out controller, shading corrector, and video RAM controller, while digitized data from the VDM are written directly into the video RAM which can be accessed from the CPU through DMA channel. The TV camera used was a Hamamatsu C-1000 vidicon camera which has about 1000 x 1000 resolution elements by 1:4 interlace. Sixteen-point sampling for each scan line was achieved by this configuration in spite of the use of the relatively slow combination of sample and hold circuit and A/D conver-ter, which has 3 µsec access time. Digitizing period for whole frames was about 1.1 sec. for 512 x 512 samplings under 2:1 interlace ratio, with 8 bit accuracy. Further, a combination of an analogue and a digital shading corrector controlled by the CPU enabled a real-time and flexible shading correction.
Pin Hole Detector For Mirror Finish Surface Using ITV Camera
Author(s):
Toshio Sakata;
Morimasa Nagao
Show Abstract
This paper describes a Pin Hole Detector designed for small surface defect detection on a mirror finish high density magnetic disk using an industrial television camera. In this system, the utilization of a silicon vidicon is successful for the line scanning method. ITV function for detector and image monitor contributes to system simplification and has various advantages in laboratory usage. For study convenience, inspection results are printed out in a list on a mapping form, indicating defect location and demensions. Detected defects are automatically aligned on the TV monitor view field, when this monitor is used for visual inspection, after specifying the desired data input through the teletypewriter unit.
High-Quality Laser-Beam Recording Of Color Television Signals On 16MM Color Film
Author(s):
Yukio Sugiura;
Tosio Motoki;
Hitoshi Masuko
Show Abstract
A laser beam recorder for visual recording on 16mm color film from NTSC color television signals has been developed by NHK Technical Research Laboratories. In order to obtain precision laser beam scanning, a rotating mirror deflector employing a 25-sided polygonal mirror with a diameter of 60mm and a 3-phase synchronous motor with hydrodynamic air bearings rotating at 37,800 rpm has been specially manufactured. The results of recording experiments have shown that the quality of the picture recorded on fine grain, low sensitivity Eastman color print film 7381 or 7383 is excellent.
Direct Readout System For Streak Cameras
Author(s):
Eiji Inuzuka;
Yutaka Tsuchiya;
Kiyoshi Kamiya
Show Abstract
To analyze the streak image directly, we have developed a new image processing system. The system consists of a high sensitive television camera and a microprocessor-based video image analyzer. The streak image can be observed easily on the TV monitor screen,and at the same time the video signal is digitized, then displayed with an intensity profile of 256 channels. The y factor Houtput)nu(input() is within 1% of unity over an input light range of better than 200:1 for a single video frame. By integration of 256 frames, the linear dynamic range can be extended to 1000:1 or greater. The system provides many features for the precise analysis of an intensity profile. The output is available to a chart recorder or to a host computer.
Acquisition And Automatic Analysis System For Streak Cameras (DATAIC)
Author(s):
C. Cavailler;
C. Demare;
J. Y. Le Gall
Show Abstract
Laser-matter interaction programs involve lasers of increased power and numerous diagnostics of high complexityo With the decrease in the repetition rate of experiences, each diagnostic must be stored and displayed immediately after each laser shot, to allow ad-justments of the experimental parameters. We present here the work undertaken around streak cameras to achieve the automatic acquisition, processing and display of streak images.
Automated Inspection System For Various Defects In Screen-Printed Patterns
Author(s):
A. Takaki;
S. Ishihara;
M. Naruse;
T. Yamada
Show Abstract
This paper describes a system which optically and automatically inspects various defects in a screen-printed micro circuit pattern, comparing the scanned data with pertinent stored circuit design information during Thick Film Hyblid I.C. Manufacturing. Various defects, such as Open, Short and etc., generally occur on a line in screen-printed patterns. Traditional defect inspection involved a visual inspection because an automated defect inspection was difficult, since line width and edge values in screen-printed patterns are non-uniform. This automated defect inspection system was developed by utilizing a high resolution photoscanner and stored circuit design information. This paper introduces this automated defect inspection system.
Image Data Processing For Laser Fusion Experiments
Author(s):
Yasukazu Izawa;
Tatsuhiko Yamanaka;
Takatomo Sasaki;
Chiyoe Yamanaka
Show Abstract
On-line computer-aided data acquisition and processing system has been developed and applied to the laser fusion experiments by the four beam "Gekko IV" glass laser. The system was designed as a modular-distributed system in both hardware and software. For the image data acquisition, vidicon-TV degitizer systems were adopted. Contour plots, horizontal or vertical cut and 3-D display of the image are possible on a graphic terminal.
A Method Of Tracking Moving Particles
Author(s):
Mikio Takagi;
Katsuhika Sakaue
Show Abstract
In this paper an approach to analyze the motion of many particles moving at random is described. It is very' hard to track each particle manually, especially' when. a great many sequential pictures are analyzed. So it is necessary to be aided by a computer in processing and tracking moving objects. For this purpose, an automatic algorithm. for tracking moving particles from a sequence of digital pictures produced by. a TV camera or a scanner is developed. As an example, the two-dimensional motion, analysis of moving granules in a pancreatic cell is considered.
Position Measurement Of Target Mark Recorded On High-Speed Motion-Picture Films
Author(s):
K . Shimizu;
C Ikeya
Show Abstract
It is possible to extract the contour of images without such effects as shading, by adding a circular deflec tion as sub-deflection to the image camera tube and then by extracting from them AC-portion alone. Further, it is possible to seek the mark's gradient as well as the relative deviation of the mark from sub-deflection, by effecting synchronized rectification for these video signals by means of the sub-deflecting carrier and the other carrier having a frequency twice the sub-deflecting one. The prototype model of the Mark-Position Measuring Device is realized by analogue technique, using an Image Dissector Camera.
Characteristics Of A Simple Mechanical Scanner For Digital Image Processing
Author(s):
Mikio Takagi;
Tsuyoshi Tomita
Show Abstract
A simple mechanical scanner has been developed, since input equipments for digital image processing are not so easilty available. Some characteristics such as resolution, signal to noise ratio and repeatability are studied. The features of this scanner, Which are S/N ratio, gradation characteristics, and frequency characteristics, are evaluated. The S/N ratio is improved by averaging the multiple scanned data, employing LOG-AMP circuit instead of the convertion table, and using LOW PASS filter.
Restoration Of Motion Blurred Images Using The Projection Iterative Method
Author(s):
J. Maeda;
K. Murata
Show Abstract
This paper describes the digital restoration of photographic images smeared by a uniform camera motion. It is shown that the power cepstrum of the blurred image provides a successful estimation of the Point Spread Function (PSF) of the imaging system. The projection iterative method is digitally employed as deblurring technique, in which the estimated PSF is used. The applicability of the method is demonstrated experimentally.
Measurements Of Sea Surface To Temperature From The Meteorological Satellite (NOAA) Images
Author(s):
Mikio Takagi;
Yoshiaki Kudo
Show Abstract
Digital image processing techniques have been applied to the images from the meteorological satellite (NOAA) in order to utilize the information more effectively, whereas they are observed and analyzed as analog images. Processings such as contrast enhacement, extraction of sea surface, observation of sea surface temperature, Mercator's and polar stereo mapping have been studied. AndlitLis:shown that these images can be applied to not only meteorology but also environmental measurement and fishery.
A Description Of A Projector For Viewing Ultra-High-Speed Rotating Mirror Camera Records In A Cinematographic Mode
Author(s):
Charles A. Honodel
Show Abstract
The photographic records produced by most ultra-high-speed rotating mirror framing cameras contain images which are non-standard size and non-uniformly positioned on 35 mm filmstrips. Timing and qualitative information is normally extracted from these records by mounting them in filmstrip projectors. The important, precise quanti-tative data are extracted by individual framing digitzation. In an attempt to enhance the visual qualitative movements contained in these records, we recently completed a model of a "fine-Mode Projector" which accepts the 35 mm filmstrips and provides, in a cinematographic mode, a position-corrected display on a rear-projection screen. The framing rate, including single-step, as well as forward and reverse, is selectable by the viewer.
Correction Of Spectral Images Formed By Spectroscopic Systems By Means Of Optical Transfer Functions -- Incoherent Cases -
Author(s):
Katuyuk i Kozima;
Hitoshi Kanamori;
Osao Matsuda
Show Abstract
Optical transfer functions (O.T.F.s) of a simple plane-grating monochromator were determined by both of Fourier transforms of line profiles and direct measurements. The ray-tracing method and a spectrogram of monochromatic rays were used to determine line spread functions, and their Fourier transforms gave the O.T.F.s. The direct measurement of O.T.F.s were performed by measuring responses of light beams having sinusoidal spectra, which were produced using a Fabry-Perot interferometer. A blurred spectrum of Na-D doublet was satistactorily corrected by means of these O.T.F.s. The result using the directly measured O.T.F. was the best.
Image Digitization, Preprocessing And Visualisation System
Author(s):
J, P. Tenaud;
M. Leclerc
Show Abstract
The system described in this paper has been designed to digitize and preprocess the images obtained at the "Centre d'Etudes de Limeil" (FRANCE) in the field of laser-fusion experiments. It mainly intends to set qualitative informations accessible to the physicist, and acts as an intermediary for the quantitative processing. We shall describe its organization and explain to role of its main functions (digitization of photographs, data storage, coding, preprocessing and visualisation, reconstruction).
Generation Of Three Dimensional Display From Many Sectional Images
Author(s):
Mikio Takagi;
Takehiro Kurono
Show Abstract
In medicine and biology, the 3-D models are made to study the 3-D structures of objects, by tracing edges of images on thick paper, cutting the patterns and putting them together. Then, digital processing techniques; namely the registration of many sectional images with 4 registrated marks, edge extraction, and half-tone graphics, might be introduced to solve this problem.
Optical Pseudo-Color Processing For Moved Objects
Author(s):
Oichi Atoda
Show Abstract
A method of optical pseudo-color representation is introduced for distinguishing height distribution of a solid object, flow velocity distribution of fluid and so on. First, a photograph is taken in a proper way so that each part of it posesses a bandpass spatial power spectrum whose center frequency represents height or flow velocity at the corresponding part of the object. Then the "frequency-coded" transparency is converted to colored image by a coherent optical processor with white light illumination.
Reproduction Of Color Image By Monochromatic Microfilm
Author(s):
T. Ito;
T. Yoneda;
H. Higashi
Show Abstract
We have developed a technique for reproducing color television images from monochromatic micro-film or 35 mm monochrofilm with a color television camera. This technique makes possible the storage of film for long periods at low cost. Practical application of this technique will make possible its use in a wide field requiring the recording and storage of color images such as in medical science, vision education etc.
High Speed Photography Of The Plasma Flow And The Projectiles In The T.U.M. Hypervelocity Accelerator
Author(s):
E. Igenbergs;
H. Kuczera;
B. Schroder
Show Abstract
The hypervelocity accelerator at the Technische Uni-versitat Munchen, FRG, accelerates small projectiles (0.1 to 1.0 mm diameter) to velocities around 20 km/s. The photographic equipment consists of two Cordin single-frame image converter cameras and one TRW image converter camera with streak units and multiple-frame units. They are used for plasma flow diagnostics and the measurement of the position and the velocity of the projectiles. The single-frame cameras are triggered with a Laser light bar and the photographic measurement of the projectile velocity will be compared with Doppler-Radar.
Flow Visualization In The Combustion Chamber By Spark Tracing Method
Author(s):
Y. Nakayama;
K. Aoki;
H. Ohta;
K. Kajiyama
Show Abstract
A flow in the combustion chamber of an engine is very complicated and it is very important to grasp the flow field for the design of the chamber. This study deals withthevisualization of the transient pattern of the air flowing in the combustion chamber and the observation of the effect of the difference in the combustion chamber's shapes. For the flow visualization, a new spark and radiant particle combustion method has been developed. In this method, particles are dispersed in the flow to be measured and in the spark discharge they generate radiant trails that show the flow direction. Using this method, the flow patterns, which clearly show the flow direction, are obtained. In these results, little differences are seen according to the shapes. And a flow rolling up from outward to the center is clearly recognized from the flow patterns.
Study On Combustion Process In A Diesel Engine By Using High-Speed Photography
Author(s):
Masahiko Hori;
Hiromi Sugiyhama;
Souk Hong Jo
Show Abstract
A step mirror type schlieren method has been developed to study the process of mixture formation and combustion in diesel engines. Combustion phenomena under hot running conditions were recorded by direct photography. Schlieren photography can be used to record air motion, dispersion of fuel-air mixture after wall impingement and nonluminous flame propagation. Flame growths recorded by direct photography correspond to the results of a rate of heat release and exhaust emissions. The results show that the fuel spray impingement on the wall has significant effects upon mixture formation and combustion. High-speed schlieren photography be an available method to examine diesel combustion and air motion accompanied by turbulence.
Application Of Holographic Interferometry To Combustion Analysis In A Spark-Ignition Engine
Author(s):
Shinji Kobayashi;
T . Takishita;
Y. K. Kim;
S. H. Jo;
M. Yoshida;
T . Uyemura;
Y. Yamamoto;
K. Tenjinbayashi;
N. Yokoyama;
H. Tochiori
Show Abstract
This paper describes preliminary results of the feasi-bility studies for applying holographic interferometry to internal combustion engine research. Using real-time holographic interferometer,the combus-tion process in a closed vessel and a spark-ignition engine were observed. The interference fringes were recorded by a high-speed rotating prism camera. We found that from the use of holographic interferometry, we could understand the flame propagation patterns, gas motion, heat transfer between gases and cold wall and unburnt gas temperature.
Mesures En Hydrodynamique Au Moyen De Sondes Optiques Et D'un Enregistrement Par Camera Electronique A Fente
Author(s):
Jean-Pierre Gauthier;
Michel Bouchu
Show Abstract
At the 12th International Congress on High Speed Photography in Toronto, L.L. Shaw, R.R. Donaldson, J.R. Murchie Ans T.S. Ramos Of The Lawrence Livermore Laboratory, showed how they change timing by electrical pins for a device composed of a small closed space on the pin tip, yielding a flash when this probe is shocked. The optical signal is transmitted through optical fiber and recorded by a streak camera. We use the same method in the base, but with an image-converter streaking camera to record the light signal and this makes the device more sensitive, really improves the performances and simplifies the setting-up. For example : - The small ionization space simply filled with air at normal pressure still gives an available signal even for a 100 kbar shock in the cap, or a copper flyer plate velocity of 1 mm/ /us. - The optical fiber transmitting the information from the working tip of the probe to the camera admits up to 20 dB transmission losses for a pressure of about 500 kbar. - It's possible to get a sweep speed of 50 mm//us for pressure greater than 500 kbar. The variation of the light source according to the time within its optical density is an extra available information.
Analysis Of Transient Phenomena. In Laser-Irradiated Heavy Hydrocarbons: Applications In Petroleum. Physics.
Author(s):
German Da Costa;
Jose Calatroni
Show Abstract
Basic research on physical properties of laser-irradiated heavy hydrocarbons is being conducted in order to support technological research in this field. For low power-concentrations, laser-induced thermocapillary flow is the dominant phenomenon. Experimental results and the corresponding theory are presented. Temperature-dependence of the surface tension gives rise to the formation of a surface depression, whose shape is studied as a function of time. Direct photo graphs of the laser wave reflected from the deformed surface are actually holograms of the later. Reconstructed images are presented. For higher power concentrations evaporation of the sample takes place. A photographic sequence of this phenomenon (taken at 64 frames/sec) is presented.
Visualization Of Unsteady Jets And Aerodynamic Noise Fields
Author(s):
S. N. Heavens
Show Abstract
Triggered flash schlieren photography has been used to study the jet structure and sound generation in subsonic air jets (Mach 0.6-0.8) in which the flow upstream of the nozzle exit is subjected to various types of acoustic perturbation. The experiments form part of a research study into the contribution from internal noise sources in aeroengines to the radiated jet noise. Photographs show the formation, convection and coalescence of large vortices in the jet and the diffraction and refraction of internally-generated sound waves. Strong acoustic emission is observed at 900 to the jet axis.
High Speed Photographic Study On The Oscillation Noise By The Condensation Of Injecting Steam From A Submerged Orifice
Author(s):
Shuya Kamei
Show Abstract
Frequency Analysis was carried out for the oscillation noise due to the condensation of steam injected from a submerged orifice into the subcooled liquid. The phenomena were also observed by means of high speed photographic shadowgraphy using a rotating prism camera with the speed of 3500 frames per second. Operations were conducted at atmospheric pressure, and water temperature varied in the range from 30°C to 80°C. The steam flow rate was varied from about 0.06 g/sec to about 3 g/sec. The present study has clarified that the condensation process arising from the steam-water transformation plays a most signifcant role for producing the oscillation noise of steam bubbles.
Laser Schlieren High Speed Photography For The Flame Propagation Study In The Constant Volume Combustion Bomb
Author(s):
T. Inoue;
H. Noguchi;
S. Iguchi;
T. Maeda
Show Abstract
A study of flame propagation in a constant volume combustion bomb is conducted with the laser schlieren high speed photography. The premixed gas motion and flame propagation in the bomb are visualized and recorded. As the result of this visualization, some interesting informations about the shape of the flame front and the influence of ignition timing and ignition position on the flame propagation were obtained, and then the difference of the effects of the swirl and the turbulence without main stream on combustion were clarified.
Measurement Of Flame Temperature Distribution In A Diesel Engine By Means Of Image Analysis Of High Speed Photographs
Author(s):
S. K. Ahn;
Y. Matsui;
T. Kamimoto;
S. Matsuoka;
S. Nagano
Show Abstract
A new technique which combines the high speed photography with the two-colour method was developed to measure the instantaneous distributions of temperature and soot co concentration of luminous flames. A couple of flame images is taken through two colour filters by a 35 mm high speed camera. The density distribution of each flame images which corresponds to brightness temperature distribution is processed by a Pseudo-colour system. The true tem-perature and soot concentration in the flame are calculated with the aid of two-colour principle. This technique was applied to a diesel engine. The instantaneous temperature distribution of the diesel flame showed that there exists a large uneveness amounting to 300 K.
The Measurement Of Density And Electron Concentration In Discontinuous Flows
Author(s):
E. V. Lazareva;
S. G. Zaytsev;
E. I. Chebotareva
Show Abstract
The paper suggestsa technique for determining the density and electron concentration in discontinuous flows. It is well known that the usual procedure of determining the interference pattern displacement during the passage of a shock front with the aid of the schromatic fringe is difficult where a medium of substantial dispersion is involved. To tackle the problem, an interferometer along with a spectrograph is used. The paper proposes also a technique for determining orders of interference fringes which makes it possible to identify disturbed interfe, rence patterns with undisturbed ones and find out parameters of the flow under study.
High Speed Photography For Studying The Shock Wave Propagation At High Mach Numbers Through A Reflection Nozzle
Author(s):
S. G. Zaytsev;
E. V. Lazareva;
A. V. Mikhailova;
V. L. Nikolaev-Kozlov;
E. I. Chebotareva
Show Abstract
Propagation of intensive shock waves with a temperature of about 1 eV has been studied in a two-dimensional reflection nozzle mounted at the exit of a shock tube. The Topler technique has been involved along with the inter-ference scheme with a laser light source allowing the multiple-frame recording to be done. Density distribution in the nozzle as well as the wave pattern occurring at the shock propagation are presented.
High-Speed Photography Of Flame Deformation In The Electric Field
Author(s):
G. D . Salamandra;
I. K. Fedoseyeva;
N. I. Nayorov;
O. I. Luneva
Show Abstract
Described is an apparatus used for high speed photographic recording of flame front deformation in the electric field. Experimental data are presented. Unique 'marking apertures' used in the Topler scheme made it possible to obtain in one exposure the complete information on refractive index gradient distribution in the subject under study as well as ensured high space resolution of the shadowing device used. High speed photographic recording was simultaneously carried out by framing and streaking cameras.
Schlieren Analysis Of High Current Circuit Breaker Arcs Using High Speed Photography
Author(s):
A. D. Stokes
Show Abstract
Schlieren photography has been used to probe the be-haviour of high current arcs in two types of a nozzle flow. For orifice nozzles the flow downstream from the throat ex-pands freely into the open air, and gross mixing between the hot arc core and the outer ambient is observed. For converging-diverging nozzles the schlieren records show a similar downstream behaviour, but upstream there is a clear cold flow surrounding the arc core. With high currents I ?. 2500 A a strong cloud of hot but non-luminous gas de-velops around the arc core and for I ?. 5000 A there is also a definite reverse flow of ablated nozzle products, which prevents effective arc interruption.
The Application Of Interferometric Laser Technique In Detonics
Author(s):
C. C. Tien;
C. Y. Cheng;
T. Y. Yuan;
Y. H. Hsu
Show Abstract
By adopting a velocity-measuring system which consists of three techniques, i.e., the laser Doppler effect, the multiple-beam interferometry and high-speed photography with an image-converter tube we can accurately and precisely get the function of free sur-face velocity versus time in the non-contact measurement. As com-pared with the various present traditional methods to calculate average velocity by a streak camera with its probe or by means of reflection, our system can yield more accurate and reliable results. What's more, it has provided us with a new test means for those fundamental problems such as the disputable C-J hypothesis in detonics, detonation wave model in hydrodynamics as well as the theo-retical study of state-equation of detonation products.
A Technique For Photographing Transverse Waves In Solid Explosives
Author(s):
R. Jameson;
V. Boyle;
G. Melani;
P. Howe
Show Abstract
A technique for observation of trajectories of transverse waves interacting with the detonation front in solid explosive has been developed. Emissions of visible light from a layer of argon contiguous to the explosives is stimulated by the wave interactions. Variations in the argon layer thickness permit tradeoff in resolution of fine structure and pattern intensity. A propane surround provides effective shuttering through production of carbon caused by reactions in the propane, triggered by the shock transmitted from the explosives. The shock interactions are recorded by an open shutter camera and a permanent photographic record of the triple point trajectories is obtained.
Damage And Dynamic Hardness Of Ionic Crystals By Microparticle Impact
Author(s):
M. M. Chaudhri;
A. Stephens
Show Abstract
A high-speed framing camera (framing rates up to 1.65 x 106s-1) has been used to follow the damage in NaC1 and LiF crystals by the impact of spheres of soda-lime glass and tungsten of diameter 0.1 - lmm and velocity up to 300 ms-1. The damage takes place in two stages. During the loading, plastic flow occurs on {110} planes causing cracks on shear planes, and is followed by fast cleavage cracks on {100} planes containing the impact-axis. During the particle rebound the primary cleavage cracks stop propagating, but several cracks form on cleavage planes parallel to the impacted surface. The maximum strain rates in these experiments are ~105 s-1; this leads to a considerable in-crease in the hardness of these solids.
An Optical Approach For The Observation Of Nuclear Fuel Failure Phenomenon In A Water Environment
Author(s):
S. Saito;
H. Kawamura;
M. Ogawa;
T. Fujishiro;
Y. Emori;
K. Sumita
Show Abstract
A great effort has been made to develop an experimental apparatus by optical method to observe phenomena of nuclear fuel failure in a water environment in actual in-reactor experiments. There are many difficulties to be overcome, such as high radiation fluence, limited space, shock pressure generation, fission products release. It was extracted through irradiation tests of glasses, fibers and films that non-browning glass used periscope should be recommended as, an image guide, and light is hardly guided effectively from outside source into a capsule by optical fibers or a periscope. On the other hand, ex-reactor simulation tests were successfully carried out to record photographically the transient behaviour on the surface of a heated rod by a high speed camera through a periscope with a lamp immersed directly into water in a capsule. Based on the results of these tests, an experimental apparatus for in-reactor tests was designed to observe transient behaviour of a fuel rod including fuel failure and subsequent phenomena.
High-Speed Photographic Methodsfor Coaression Dynamics Investigation Of Laser Irradiated Shell Target
Author(s):
N. G. Basov;
A. A. Kologrivov;
O. N. Krokhin;
A. A. Rupasov;
A. S. Shikanov;
G. V. Sklizkov;
Yu. A. Zakharenkov
Show Abstract
Three methods are described for a high-speed diagnos-tics of compression dynamics of shell targets being spherically laser-heated on the installation "Kal'mar". The first method is based on the direct investigation of the space-time evolution of the critiical-density region for lid-laser emission (Ne 1021 Iicm-)) by ears of the streak photography of plasma image in the second-harmonic light. The second method involves investigation of time evolution of the second-harmonic spectral distribution by means of a spectrograph coupled with a streak camera. The use of a special laser pulse with two time-distributed intensity maxima for the irradiation of shell targets, and the analysis of the obtained X-ray pin-hole pictures constitute the basis of the third method.
Shock Compression Of Polymethylmethacrylate From 20 To 80 Kilobars
Author(s):
T. Yamada;
K. Kani;
A. Morita
Show Abstract
The Hugoniot of transparent Polymethylmethacrylate (PMMA)1) has been obtained in the pressure range from 20 to 80 kilobars. The Hugoniot has been deduced by measuring the shock velocity and the shock-induced free surface velocity of the PMMA plate. The present paper describes experimental techniques in which copper flyer plates have been accelerated by a powder gun for shock compression of the PMMA plates and a high speed streak camera has been employed to observe motions of a shock front and a free surface. The present techniques have proved to be usable for measuring the Hugoniots of transparent materials with relatively high accuracy. A small discontinuity appeared in the shock velocity-particle velocity Hugoniot obtained. This might suggest the existence of a phase change.
High Speed Photography Analysis Of Cylindrical Shock Waves Generated By Explosive Charges
Author(s):
Algot Persson;
Olivier Dubugnon
Show Abstract
Utilizing explosives and a special initiation technique cylindrical shock waves were generated in blocks of polymethylmethacrylate (PMMA) and lead glass. The propagation of the shock waves was studied with a multiple Kerr-cellcamera. Two types of in-material gauges were applied to the test pieces and the shock stress recorded by the gauges was compared to that calculated from the propagation velocity determined from the photographs. In PMMA well defined cylindrical waves were generated, in lead glass however the explosive system used was unsufficient because of the more linear elastic behaviour of glass under moderate stress.
Photographic Determination Of Flight Characteristics Of Projectiles With Laser - Screen-Triggered Nanosecond Sparks
Author(s):
H. Preschern;
P. Bettermann
Show Abstract
A photographic system is presented, using a modified Cranz-Schardin slow-motion-spark method in combination with Toepler's Schlieren method, to determine the space coordinates of a projectile in free flight. Fanned-out laser beams reflected by reflex foils enable highly accurate timing of the projectile's flight and subsequently, timing of the nanosecond-spark, which is optically split into two X and Y beams. By use of two condensor lenses, an even picture field illumination in the two cameras is guaranteed. By appropriate evaluation of the pictures from one or a few units connected in series, results,not only of the space coordinates of a projectile but also of its exterior ballistic behaviour, can be obtained.
Radiative Process In Single And Multiple Wire Explosions
Author(s):
C. Y. Kang;
K. T. Kim;
M. H. Lee;
S. S. Lee
Show Abstract
Two copper wires, 0.017cm and 0.024cm in diameter and both 1.2cm long, connected in series are exploded by discharging a capacitor of 6;1F, charged to 7.5 KV, and the two light flashes with short duration and time separation are observed. They are detected by two cameras which take the photographs of a chopper aperture revolving at the speed of 42 rps. From the circuit equation, the prevaporization solution is obtained by the iteration method applied three times. However, the convergence of the power series is found poor. Then, a computer calculation is made to obtain the vaporization time for the two wires. The time separation of the two optical flashes are found to be 2.2 psec which agrees fairly with the value about 3 l.sec obtained by comparing the two photographs.
Evaluation Of Shaped Charge Jet Fragmentation On Target Penetration
Author(s):
E. Perez
Show Abstract
In this work the effets of fragmentation process on shaped charge jet penetration have been examined by means of X Ray cinematography (6 tubes). Visualizations of the emerging jet after target perforation show that : - the maximum penetration is produced by a completely fragmented jet - even at very little standoff an important part of the total penetration is produced by jet fragments - if the jet fragments are well aligned, the penetration process is not affected by the distance seperating them.
Examinations With Soft X-Ray Flashes Of Wire Explosions In Layers Of Liquid
Author(s):
R. Germer;
R. Schutt
Show Abstract
Exploding wires produce shock waves in thin layers of liquid between plane solid plates and induce compression phenomen. principally similar to those induced by spark discharges. Specific differences and typical phenomena of wire explosions can be detected using soft X-ray flashes. The interaction of several shock waves leads to compression and cavitation areas. The results can be varied using different arrangements of the exploding wire like circles and crosses. The density of energy in this shock wave source is lower than in our experiments with sparks and can be reduced to minimum values to study the influence of shock wave energies. The reHainder of the exploded wire gives information for energy calculations.
Behavior Of Human Feet In Locomotion
Author(s):
K. Tsuchiya;
S. Morimoto;
F. Kasahara
Show Abstract
To design the artificial feet for the amputees, the behaviors of human feet and of the conventional artificial feet in locomotion are observed using a high-speed cine-camera of 400 frames per second. Angular displacement of each joint of lower limb is analyzed with synchronized data of floor reactions. Some remarkable differences between the behavior of human feet and of artificial feet are recognized in the phase of heel contact and push off. These differences can not be find from the data of conventional clinical gait analysis using normal speed cine-camera of 10-60 frames per second. Besides above, it is recognized that high speed cinematograph will give us more information on the contraction of muscles than E.M.G. method.
Application Of Holographic Interferometry To The Study Of Hearing Mechanism
Author(s):
Yoshio Ogura;
Yu Masuda;
Ma sami Miki;
Tsuneyoshi Uyemura;
Yoshitaka Yamamoto
Show Abstract
Holographic interferometry was applied to medical investigation regarding the vibration analysis of several parts of the sound conducting apparatus of mankind and some experimental animals. Vibration patterns of the tympanic membrane, the auditory ossicles and the skull were demonstrated and the results were discussed. Merit of holographic interferometry as a new technique of vibration analysis was emphasized, and several points to be considered by its application to medical investigation were also discussed.
A Study In High Speed Cutting With Dental Burrs
Author(s):
W. Thompson;
R. Hooley
Show Abstract
The work presented details the development of an experimental proced-ure enabling investigations into dental cutting mechanics to be carried out. Use has been made of high speed cinemacrography with framing speeds up to 22,000pps being recorded. This provided a clear view of the action of modern high speed rotary dental instruments and allowed analysis of chip trajectory dynamics and cutting efficiency at different cutting parameters.
Study On Impact Of A Golf Clubhead And A Ball
Author(s):
G Stunoda;
I . Tensho;
Y. Nobuta;
F. Sato
Show Abstract
In the part I of the present investigation we found that the torsional compliance of the shaft does not play an important role on the direction of take off of the ball. In the part II we have investigated the effect of conditions of impact on the ball flight varying impact points and the surface conditions of the iron head using high speed photography. When the impact point is higher than the center of gravity of the head the face angle becomes several percent larger after impact and vice versa. The effects of surface roughness and scoring of the face are not so significant.
High Speed Microphotography Of Elements Of The Glass Grinding Process
Author(s):
M. Schinker;
W. Doll
Show Abstract
Investigations of the industrial process of glass grinding using diamond tools have in the past been generally confined to an examination using microscopy of the surfaces formed after grinding. In this work an experimental arrangement has been developed to observe the fracture process whilst it is occurring in the micro region around the tip of a diamond which is moving at speeds between 10 ms-1 and 100 ms-1. For this an optical system of high magnification and resolution is used together with sufficient depth of field, coupled to a camera system of high framing rate and correspondingly short exposure times.
A Proposal To Improve High Speed W-C Drills For Printed Circuit Board Based On A Photographic Observation
Author(s):
Tomozo Kawakita;
M. Sasaki;
H. Kitagawa;
K. Mori;
K. Shirai
Show Abstract
Hard W-C alloy drills used in the production of printed circuit boards must cope with the increasing requirements for higher revolution and feeding speed. Under severe working conditions both the heat and the epoxy-smear generated on the copper conducter surface are apt to be fatal to successful drilling. We clarified the behaviour of drills and drilling chips in various conditions by using a "STROBOKIN" and developed a new method termes as 'back-cut drilling'. By this method we use back-cut drills having special upward blades and during the idle upward feeding period are able to cut off thin layers around a drilled hole and to remove the generated epoxy-smear effectively.
Machine Analysis For Fault-Finding And Design Purposes
Author(s):
D H Pimley
Show Abstract
This paper reports on the use of high speed cinematography as applied to the analysis of machine, mechanical assembly and process movements to assist in overcoming fault conditions and to provide data to enable improvements to be made in the design of such equip-ment to produce greater efficiency and reliability.
Behaviours Of Water Entry Bullets And Cavities At High Entry Speeds
Author(s):
Shoji Kageyama;
Tositika Usui
Show Abstract
An experimental study of the behaviour of a bullet(caliber 7.62mm Ball M2) at an oblique water entry has been performed. The entry speed is adjusted to a value of about 300m/s. The range of entry angles is from 24 to 27 degrees. It is shown that the bullet runs stably only when the bullet travels broadsiding with the nose-down and during this period the trajectory can be fitted by an ana-lytical expression. After this phase the cavity collapses near the lowest region of the bullet trajectory and then the bullet goes up.
Streak Recordings Of Dynamic Forming Of Metal Liners
Author(s):
Hans J. Blankenagel;
Dieter Ludwig
Show Abstract
The presented method for recording fast events using the streak technique was developed for an investigation of the deformability of metal liners in collaboration between the Institut fiir Verformungskunde and Gielereiwesen of the Technical University of Munich and the Messerschmitt-B61-kow-Blohm Company, Schrobenhausen. Object of the study was the high energy rate forming process of different metal liners produced by explosively generated shock waves. Streak records of the axially symmetrical collapsing and axially accelerated liner, forming a projectile, made it possible to get a quantitative analysis of the forming process in a 5.10-6 sec period of time. By an adequate evaluation and caluclation method it was possible to describe a high velocity forming process with rates up to 2000 m/sec.
High Speed Fracture Of Metals Studied By Cinematographic, Magnetic And Radiographic Methods.
Author(s):
F. Olive;
J. Marilleau;
R. Loichot;
C. Peyre;
A. Nicaud
Show Abstract
High explosives may be used to obtain strain rates in solids within the 103 to 105 s-1 range. We have employed this technique to study the dynamic rupture behaviour of some materials (such as steels, aluminium, zircaloy, uranium alloy) in spherical and cylindrical expansion. Several experimental methods of observation and measurements are employed simultaneously : high speed streak and framing cinematography, magnetic diagnostic and sometimes flash radiography and recovery of fragments. Our results are in accordance with a fracture criterium, derived from the Tresca plasticity criterium, relating an Equivalent deformation "Er to an equivalent strain rate co. A transition in properties of the dislocations wich become supersonic around 104 s-1 could explain the high deformation rates observed.
Application Of Grin Fibre (SELFOC Fibre) To High-Speed Raster:Photography
Author(s):
Kung-Tsu Tung
Show Abstract
At present the taking rate of raster high-speed photography is limited mainly by two factors: (1) the grain size of the photo-sensi-tive emulsion; (2) the size of the image formed by individual raster element. To reduce the grain size of the film while maintaining its speed is the honorable duty of the photo-chemists. To reduce the image size the engineers have endevoured to machine the dies with which the lenslets forming the lenticular plate is pressed as fine as possible, and is reported that the diameter of each lenslet has been reduced to 60/urnin U.S.S.R.1)2) It seems dif-ficult to get further reduction. With the birth of grin fibre or sel-foc fibre a new way is opened to make the image size still slaaller and indeed the more efficient way is to use the tapered grin fibre, forming images of the secondary and tertiary order of increasingly smaller sizes.
A 1024 x 1024 Image Digitilizer With Slow Scanning Storage Tube Used In Hydrodynamics Studies.
Author(s):
P. Chapron;
C. Le Drean;
J. Marilleau;
J. J. Lefebvre;
R. Loichot
Show Abstract
We present a system fitted for digitizing pictures coming from high speed cinematography systems as well as pulsed radiography. The system is built around a slow scanning television tube which provides a resolution of 1024 x 1024 -512 x 512 or 256 x 256 pixels coded on 256 levels assigned to an adjustable range of optical density. The size of pictures or X rays images may vary from 24 x 24mm2 up to 400 x 400 mm2. Geometrical distorsion ra-te is better than 10-3 and photometrical error about 2 x 10-3 after processing. The reading noise added to the picture is equivalent to 0.7 x 10-2 D.
Dynamic Range And Recording Efficiency Of Picosecond Streak Cameras
Author(s):
S. Majumdar
Show Abstract
The intensity dependent pulse broadening in present day photoelectric streak tubes was explained by the author as a result of bottlenecking inside the photocathode, in the 12th ICHSPP. The theory is further explored in the light of further information since the last congress. It is established that the intensity depended pulse broadening is dependent on the photocathode quantum efficiency and that the time dispersion is dependent on time resolution limit expected from the system. Both these phenomena were expected from the theory of photocathode bottlenecking and can not be explained by Child-Langmuir space charge effects. A reciprocity failure in phosphors for short electron pulses is also reported.
The Picotron 100 A New Picosecond Image Converter Tube With A High Dynamic Range
Author(s):
S. Majumdar;
P. Jaanimagi;
M. C. Richardson
Show Abstract
The performance of a new picosecond streak tube, the Picotron 100, is described. The tube has a low and variable electron optical magnification. For the first time, time resolution of 80 picoseconds with a useful dynamic range of 20 is obtained from a single stage streak tube. By using intensifiers, a dynamic range as high as 120, at 5 picoseconds time resolution, is reported, also for the first time. A dynamic range of greater than 1200 was obtained from a 25 picosecond pulse when the technical time resolution was set at 6 picoseconds. These results, which are better than any so far reported, have been made feasible by reducing the electron-optical magnification of the streak tube.
A High-Speed Electrooptic Shutter For High-Speed Photography And Laser Generation Control
Author(s):
T. A. Kuzovkova;
E. V. Nilov
Show Abstract
An electrooptic shutter based on the use of the longitudinal rockels effect in DKDP crystals with a kw non-active loss was devised. Due to concentration of the controlling electric field on a short crystal portion the modulating element length could be reduced by a factor of 1.5-2 as compared to the length in the known constru-ctions. The shutter was applied to a ruby laser used in framed shutterless high-speed cinematography in order to generate a lighting pulse train. For controlling the mode composition of the generation of a laser with a plane geometry cavity a space-time light modulator which is a combination of the shutter and a smooth edge diaphragm was developed. The modulator has comparatively low non-active loss and can control the spatial development dynamics of the laser generation. It's use may be of interest for the purpeses of high-speed motion-picture holography.
Dynamic Range Measurement Definition Thursday, August 24, 1978, 1800 to 2030 Hours
Author(s):
S. W. Thomas
Show Abstract
We have agreed upon dynamic range measurement definition for use by commercial manufacturers of electro-optic streak cameras. Dynamic range is to be defined as the ratio of the peak amplitudes of an upper and lower usable signal. The limits of usable signal are to be the points at which the pulse width at half maximum is broadened or changed by 20% as referenced to the width of a pulse near the middle of the dynamic range.
Report On The Congress
Author(s):
Hiroyoshi Saito
Show Abstract
The 13th International Congress on High Speed Photography and Photonics had been originally scheduled to take place in the Soviet Union. At the 12th Congress at Toronto, however, the Soviet Union declined to host the Congress in hopes of having it timed to coincide with the 1980 Olympics. It was rather hastily decided for Japan to host the 13th Congress.
Memories Of The 13th Congress, Tokyo
Author(s):
Harold E. Edgerton
Show Abstract
The national delegates to the 12th International Congress on High-Speed Photography, held in Toronto, Canada in 1976, were delighted to receive an invitation from the Japanese delegates to convene in Tokyo during the week of August 20, 1978. Soon, many people were making plans for their attendance and participation. Technical papers have to be written and equipment displays have to be planned. One of the real uses of an International Congress is to force the issue of a preliminary description of one's work. There is nothing like a time deadline to finish a proposed paper! It would be a very good idea to have the complete paper in hand before the summary is written, but who does it that way?
