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Proceedings Volume 1155

Ultrahigh Speed and High Speed Photography, Photonics, and Videography '89: Seventh in a Series

Gary L. Stradling
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Proceedings Volume 1155

Ultrahigh Speed and High Speed Photography, Photonics, and Videography '89: Seventh in a Series

Gary L. Stradling
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 17 January 1990
Contents: 1 Sessions, 68 Papers, 0 Presentations
Conference: 33rd Annual Technical Symposium 1989
Volume Number: 1155

Table of Contents

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Table of Contents

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A Call For Standards The Demise Of Specsmanship
Dennis E. Caudle
Over the last ten years, standardization in the video industry has taken both the high road and the low road. Manufacturers of broadcast and consumer video products have reaped the benefits of significant standardization, including ease of marketing and a logical progression of product improvement, while customers enjoy product compatibility, ease of comparison and a degree of standardization in quality. Unfortunately, industrial video manufacturers have done a very poor job of standardizing products and uniformly specifying product performance.
Standards And Their Impact On Technology
Lincoln L. Endelman
The needs for standards and the processes to provide them are very complex. Standardization is dependent upon voluntary and nonvoluntary agreement among individuals, companies, various organizations, and countries around the world. The agreements on standards, which sometimes take five to ten years, are hindered by monetary considerations, relinquishment of patent rights, disagreement among nations on dimensions in metric or the English system, and professional jealousy among some individuals. Standards, Standards, Standards - what a boring and uninteresting topic. Why did I ever agree to speak to you about something that most people take for granted and don't even bother to pay much attention to until they encounter a situation where a nonstandard item creates a problem. Have any of you ever bought a roll of 35mm film for your foreign made camera and found out that it needs 32mm film? That could have happened to you in the late nineteenth or early twentieth century. Yes, we know that, you say, but that's not a problem anymore. Well, how about when you try to put a Beta cassette into your VCR that uses VHS cassettes? Have you tried to fit a Minolta lens onto a Nikon camera? But enough, you all have the idea. Standards were developed to make interchangeable components compatible with other equipment, no matter who made it or where it was made. Some companies and countries deliberately made things different to protect their inventions and profit by their uniqueness. More and more attempts are being made to reduce the international differences in technology and establish a common ground for trade and commerce. The European Common Market is in the process of eliminating many of the barriers to free exchange of goods, services, and even moving to a universal currency. This all sounds good for Europe, but what about the USA and the rest of the world. The United States has fought the change to the metric system for almost two hundred years. Our electrical system and the electrical systems of many parts of the world are not compatible. There are at least five video systems throughout the world. Standards have a direct impact upon almost every area of living in today's multi-complex world. Medicine, business, entertainment, science, education, travel, and especially manufacturing. Think about the American made automobile with the Japanese engine - everything is metric.
Modulation Transfer Function Measurement For Solid-State Intensified Cameras
Jeffrey H. Lewis
As image acquisition and display systems continue to increase in resolution, accurately measuring their performance becomes more and more difficult due to the lack of standardization in measurement procedures. A method is needed for measuring the performance of an imaging system that can be duplicated easily and inexpensively. This paper presents a simple method of determining the modulation transfer function (MTF). Although there are more precise methods of obtaining the MTF, the method presented here can be performed simply and inexpensively. In addition, it minimizes the effects of error terms, thus facilitating the comparison of similar imaging systems. For the purpose of comparison these error terms, in most cases, are small enough to be considered insignificant. There is a brief explanation of some of the limitations associated with imaging systems followed by a sample data set.
Pulse And Microwave Characterization Of A Fiber-Optic Transmission Link
P. D. Sargis
Experiments at the Nevada Test Site require high-bandwidth recording systems with wide dynamic range. A 1300-nm fiber-optic transmission link is being investigated for this application. This system performs with a bandwidth of 3 GHz and a dynamic range of 100. To gain a better understanding of the large-signal response of semiconductor laser diodes, an analysis of large-signal vs small-signal response has been conducted using pulse and microwave techniques.
The PI-74C Hand-Held Computer, An Instrumentation Photographer's Helper.
Donald H. Peterson
The PI-74C hand-held computer/calculator enables instrumentation photographers and test engineers to perform numerous calculations related to camera usage. BASIC language programs loaded into the PI-74C enable the user to run a complete job analysis or to solve various single-solution programs for given camera applications.
Analysis Of High Speed Framing Camera Data For The Development Of Material Models Used In Penetration Mechanics.
Donald R. Snyder, Leonard L. Wilson, Joel W. House
The results of penetrator and target interaction is an interesting and important area of science. To aid designers of armor and armor penetrators, analytical tools have been developed to describe the results of penetration events. The success of the analytical model is dependent on the ability to accurately describe the material response under dynamic conditions found in the penetration process. This paper describes the use of high speed framing camera photography for the development of material behavior models. One test to characterize material behavior under dynamic conditions is the cylinder impact (or Taylor) test.1 Shadowgraphic photography of the impact event at very high framing rates provides investigators with time resolved data needed for experimental characterization of material behavior.2'3 Results from this investigation have been used in the development,.of new theories which provide analytical description of the cylinder impact test.'
Method For Analyzing The Flash X-Ray Spectra Using Attenuation Data
Hiroshi Isobe, Eiichi Sato, Satoshi Kawasaki, et al.
X-ray spectra from a single-flash x-ray generator were determined by means of attenuation analysis using a new type of function fitting the bremsstrahlung spectra of the flash x-rays. These attenuation data were obtained by using a set of aluminum steps positioned at 1m from the source, while the x-ray detectors were the elements of a thermoluminescence dosimeter (TLD) which were placed behind the steps. The relative response function of the TLD element was also determined by using attenua-tion data achieved with the conventional hot cathode x-ray spectra measured with a spectrometer utilizing a lithium-drifted silicon detector. The flash x-ray generator was a single high-intensity type utilizing a hot cathode radiation tube used for biomedical radiography. This generator may be used for condenser charging voltages of less than 120kV; the pulse widths of the flash x-rays were less than 100ns. The peak intensities of the flash x-ray spectra tended to shift to the high energy region according to increases in the charging voltage and insertion of aluminum filters. The energy latitude of the flash x-ray spectra were wide compared to those obtained using a conventional x-ray generator used for medical radiography.
Specifications For Intensified Solid-State Cameras In Photon-Starved, Small-Image Applications
Richard C. Smith, Mark A. Sartor, Albert Lazzarini
New scientific applications for cameras/imaging arrays continually push the state of the art to new limits. Whereas traditional applications use these devices to generate pictures (qualitative data), these same devices are being used more frequently as two-dimensional radiometric tools. As these new applications levy more stringent requirements on these devices, it has become quite apparent that the basic information offered on specification sheets by camera vendors is inadequate. Further, a lack of any industry standard in these specifications makes accurate comparison of similar devices (by different manufacturers) nearly impossible without actually testing them side by side. Of particular interest to our application is achieving a good signal-to-noise ration (SNR) at low light levels for small images, including those of point sources. Statistical fluctuations in intensity readings of individual pixels depend on several parameters in addition to irradiance and inherent camera noise. Among these are (i) the size and shape of the point spread function, (ii) the origin of causes of blur, and (iii) the size and shape of the image. For example, pixels irradiated with a flood beam register additional signal that is associated with their neighbors due to blur. Pixels irradiated individually with a point beam can lose signal due to blur. Their signal is thereby lower and their shot noise is worse. Accordingly their SNR is degraded. We present a set of parameters whose determination can serve in predicting the sensitivity and SNR for use in a wide variety of applications.
Study On The High-Voltage Long-Gap Discharge By Using The Image Converter Camera
Hu Shaolou, Li Huijun
By using the image converter camera, we studied the high voltage long-gap discharge phenomena, particularly, the process of corona and precursor discharge varying with concerned parameters. Since the sustained and intervals of the precursors are about a few deci-microsecond to a few microsecond, the framing photography might lose signals, the scanning technique with whole vision field has been used. To solve the cynchronizing problem, we have developed a technique which can trigger the camera by means of spark gap-optoelectronic transformation. Some protecting measures are also described in this paper.
Multiple Output Photodiode Arrays
Don W. Lake
High frame rate imagery fulfills the need for increased time resolution in solid state video applications. Conventional RS170 style video produces 60 field/30 frame line sequential images. Many consider these rates to be "real time," yet they fall short in many crucial situations. Film cameras address this inadequacy by offering "slow motion" capability.
Fast Framing Detector Systems For Sensor Applications
John A. McNeill, Chris A. Raanes
Requirements for real time sensing and correction of optical wavefronts have driven the development of fast framing camera systems. Performance requirements for wavefront sensing are discussed, as well as requirements for similar applications such as medical imaging and machine vision. Advances in detector arrays, electronics design, and A/D converter technology have resulted in a range of high speed, wide dynamic range cameras. Test results are presented for a typical system which will be used in a medical imaging application.
64 Output 1024X1024 Pixel Imager For High Frame Rate Applications
Richard A. Bredthauer
A 1024x1024 imager suitable for high frame rate applications is described. Sixty-four parallel outputs are incorporated to achieve high resolution fast framing with reduced individual port data rate. Layout segmentation and a separate masking step provides for operation as either a frame store or full frame imager. This paper discusses the architecture, fabrication and packaging of the imager.
A High-Speed Video Camera And Recorder
John E. Tanner
A high-speed video camera and recorder system is under development that will capture data at 2000 frames per second and store 2000 frames of data in solid-state digital memory. One possible configura-tion consists of a single unit camcorder that will measure approximately 6" x 6" x 12" and contain 128Mbytes of dynamic RAM and 64 flash A/D converters. Camcorder outputs include standard video and a digital port. To supply the high-speed data, a custom high-speed MOS imaging array prototype has been designed, fabricated, and tested. Preliminary tests of the 64 x 32 pixel device show imaging operation at more than 1000 frames per second. A 256 x 256 pixel array projected to achieve 2000 frames per second is under development.
Dynamic Range Enhancement Techniques For Solid State Gated Intensified Cameras
Dennis E. Caudle
This paper defines two types of dynamic range as applied to gated intensified solid state cameras.It also explores several techniques of extending the dynamic range and addresses the probable implications of these techniques relative to specific applications.
A New 80-Frame Continuous Access Rotating Mirror Camera
Vance C. Parker
A new 35mm format continuous access framing camera has been developed that provides significant photographic improvement for the researcher. The camera is capable of 2,250,000 frames per second.
High Speed Single Transient Microwave Spectrum Analyzer
J. Stokes, J. Ogle, L. Looney, et al.
Recent experiments have required the measurement of short pulse high bandwidth microwave spectra. To meet this need we built a GHz-bandwidth acousto-optic spectrum analyzer. The hardware includes a HeNe laser, collimating optics, Bragg cell, streak camera, microchannel plate intensifier and film cassette. The frequency range measured was 350-2000 MHz with a dynamic range greater than 20 dB. Microwave pulse widths from 10 ns were measured with this system.
Characterization Of Some Common CRT Phosphors
W. E. Flynt
Image intensifier tubes and other electro-optical devices use phosphors as a part of their output structure, and the temporal behavior seems to be a source of confusion among those who specify the requirements for these devices. Some of these phosphors...in particular the common P-20...exhibit a "non-linear" charactristic, in that the decay behavior is strongly dependent on the duration of exitation, and less so on current density. This paper will attempt to clarify some of these issues for the spec writer, without any treatment of the physics or chemistry of the phosphor materials.
High Speed Photography By Using Two-Dimensional Acoustd-Optic Lattice Deflection And Its Application
He Anzhi, Yan Dapeng, Ni Xiaowu
This paper presents the principles and application of high speed photography which is by using technique of acousto-optic deflection to take high speed picture. In the this new method of high speed photography, 10 x 10 lattic picture is recorded on a fixed film (10 x 10mm) by time-serial. This technique can be used to record various transient process by high speed intcrfcromctry. The exposure time is from 10-5to 3 x 10-6sec by using C.M laser as source and is about 10-9sec by using serial pulse laser. The framing frequency is about 105frame / sec.
A High Panning Rate Mount
Thormon O. Ellison
A camera mount designed to pan in synchronization with a high velocity projectile using a rotating mirror is described in sufficient detail to enable potential users to build a similar device.
Two Hundred Field Per Second Airborne Video System
David L. Newkirk
The Naval Weapons Evaluation Facility (NWEF), Albuquerque, New Mexico, conducted flight tests in November of 1983 to evaluate the NAC HVRB-200 high speed airborne video system for operation and structural integrity in the external military flight environment. The flight tests were successful, but due to budget restraints, shortage of manpower and required design changes, the upgrade to video was placed on hold. Finally in 1986. additional MAC high speed video equipment was procured and by November, NWEF had finished design, built the required control units and instrumentated the first A-7 aircraft. The NWEF system has been the primary data collection media used since then on all project missions conducted by NWEF. With many hours of flight time and extensive experience using the A-7 system, NWEF has designed, built and installed the F/A-18 high speed video system. The first system test flight was conducted on 10 July 1989 and again proved successful.
Miniature Programmable Image Capture And Gated Intensifier Camera Control System For Laser Range Gating And High Speed Imaging Applications.
Dennis Walker
This paper describes a recently developed Image Mowry and Camera Control Unit (IPECU) intended for use with intensified camera products. Over the past few years intensified camera technology and associated applications have became more sophisticated. The stand-alone intensified camera has become increasingly more difficult to interface with custaner's time critical applications without the aid of sophisticated control logic. With requirements for adaptable and programmable interfaces with image storage capabilities, X.E.S. has developed a flexible system that supports a wide range of intensified camera applications such as laser range gating, intensified multispectral imaging, high speed image capture and surveillance.
Gated Intensifier Video For Ballistic Instrumentation
W. Shipman, C. Law, T. Brown
Gated intensified video cameras offer advantages of realtime imagery, short exposure times, compact size and cost savings over conventional film cameras for synchro ballistic photography. A video system including event sensor, programmable delay timer, and gated intensified camera is described which was used to record video images of 20 mm, 30 mm and 5 inch gun fired projectiles in flight. Reproductions of representative video images are included.
Ballistic Applications Of Lasers
G. R. Hough, D. M. Gustafson
Employment of modern laser systems to improve ballistic gun range operations and related data acquisition is discussed. Of key importance is their use as motion sensors and as image forming instruments. Specific application in the LTV Missiles and Electronics Group, Missiles Division, ballistic research gun range is emphasized. A powerful new approach for determination of behind-armor-debris mass and velocity fields is also described. It is based on holograms of the debris field which have been made here for the first time.
Image Intensification For High Speed Videography
Kris S. Balch
Light amplification techniques are needed in the more demanding high speed motion analysis applications. Some of these applications have been very difficult if not impossible to capture with videography. Applications requiring blur free images of subjects with very high velocities are solvable with this technology. This technology will improve the depth of field under normal ambient lighting or added fill light conditions. It will also improve the images, provide less blur at high velocity. The light amplification technique to be discussed uses a two stage intensifier coupled to a solid-state sensor array. This sensor is the imaging element for the KODAK EKTAPRO 1000 Motion Analyzer. The first stage shutters the image at microsecond rates. The second stage amplifies the light from the first stage over a short integration period. The coupling of these two stages to Kodak's 1000 frame per second motion analyzer has significantly extended the state-of-the-art capability for high speed videography. Videography users now have a solution for applications with scene illuminations below 10 lux, shutter speeds at microsecond rates , and framing rates above 1000 fps. Kodak's sensor integrates light over a 1/1000 second exposure. Adding a microsecond shutter shortens the light integration time to 1/1,000,000 second. Increasing the problem in applications with low scene illumination is the short integration period. Ambient light levels of 1/100 of normal office illumination level are not uncommon. This requires a light gain of approximately 10 to 12 f-stops. To appreciate the difficulty in achieving this level of performance, a technical overview of the intensifier's operation is given. Many design tradeoffs encountered during its development are discussed in this paper.
Underwater Test Diagnostics Using Explosively Excited Argon And Laser Light Photography Techniques
John Wisotski
This paper presents results of photographic methods employed in underwater tests used to study high-velocity fragment deceleration, deformation and fracture during the perforation of water-backed plates. These methods employed overlapping ultra-high and very high speed camera recordings using explosively excited argon and ruby-laser light sources that gave ample light to penetrate across a 2.3-meter (7.54-foot) diameter tank of water with enough intensity to photograph displacement-time histories of steel cubes with impact speeds of 1000 to 1500 m/s (3280 to 4920 ft/s) at camera framing rates of 250,000 and 17,000 fr/s, respectively.
High Speed Video Radiography
D. J. Rogerson, P. N. Keller
High-frame-rate video offers many advantages compared to motion picture film particularly when coupled with low-light level capabilities. A high speed low light level video camera was developed capable of framing 1000 images per second at a scene illumination as low as 10-5 ft cndls.
Multiple-Line Laser Doppler Velocimetry
J. Veaux, P. Mercier, G. Behar, et al.
Laser Doppler velocimetry has became a precision tool for obtaining velocity-vs-time profiles of the motion of shocked specimens . Up to now this technique requires the use of CW-single mode Argon laser . This type of laser gives the best trade off between the necessity to have a spectral width smaller than the interferometer's free spectral range and the one to have convenient high power ( SW in the visible range ) .However it barely enables us to anlyse over a wide range of the behavior of diffusely reflecting surfaces . Furthermore this laser is cumbersome ( heavy , cooling system required ...etc ) and hardly removable . This paper presents a new conception of laser Doppler interferometry . It based on the matched filter principle using a pulsed broad bandwidth dye laser ( power > 'I kW , FWHM : 20 (,s ) coupled to a Fabry-perot interferometer acting as a spectral modulator and demodulator . In this context without any kind of laser amplifier we can record over along period of time the Doppler frequency shift of diffusely reflecting surfaces . Also we are working out the design of a multichannel interferometer. Furthermore mode stability no longer depends on emission reliability of a single mode laser but on the Fabry-Perot interferometer mechanical characteristics . Finally the system is cheap , requires no cooling system and can be easily duplicated.
Interferometry And High Speed Photography Of Laser-Driven Flyer Plates
D. L. Paisley, N. I. Montoya, D. B. Stahl, et al.
Laser-driven thin (2-10-1 thick) plates of aluminum and copper are accelerated to velocities ≥5 km/s by a 1.06-11 wavelength Nd:YAG 8-10 ns FWHM laser pulse at power densities 0.7-4.0 GW/cm2. Accelerations ≥109 km/s2 have been achieved. The acceleration and velocity of these 0.4-1.0-mm-diameter plates are experimentally recorded by velocity interferometry (VISAR)1 and the planarity of impact by streak photography.2
Single Camera Solution To Weapon Separation Testing
Joseph G. Turner
To ensure safe deployment of weapons as they separate from an attack aircraft, flight testing and data analysis of the weapon release must be performed. To acquire the weapon data in such a confined environment, a single camera algorithm solution was developed. This paper summarizes the methodology and mathematics involved in this approach as well as the accuracies and future planned improvements.
Compact Pulsed X-Ray Generator Operated At High Repetitive Rates
Hiroshi Isobe, Eiichi Sato, Shingo Kimura, et al.
A repetitive pulsed x-ray generator achieved with a compact diode utilizing a new type of cathode for biomedical radiography is described. This generator consisted of the following components: a high-voltage power supply, two ceramic condensers of about 850pF, a repetitive impulse switching system, a turbo molecular pump, and an x-ray tube. Since the high-voltage pulser employed a modified Marx circuit, this pulser produced twice the potential of the condenser charging voltage. The x-ray tube was of the demountable-diode type which was connected to the turbo molecular pump and consisted of the following components: a rod-shaped anode tip made of tungsten, a plane cathode made of aluminum and carbon, and a vacuum vessel made of glass with a diameter of 50mm. Two condensers were charged from 30 to 100kV, and the output of this pulser ranged from 50 to 180kV. The x-ray pulse widths primarily increased according to increases in the anode-cathode (A-C space) and their values ranged from 20 to 100ns. The repetitive rate was determined by the condenser capacity, the charging voltage, and the current capacity of the power supply, and its maximum value was about 100Hz. The time integrated x-ray intensities were less than 4.0pC/kg at 0.5m per pulse when the discharge capacity of about 430pF (Marx Circuit) was employed. The effective focal spot size was determined by the diameter of anode tip and its value ranged from 0.5 to 3.0mm in diameter.
Repetitive Pulsed X-Ray Generator Utilizing A Triode
Eiichi Sato, Satoshi Kawasaki, Hiroshi Isobe, et al.
A repetitive pulsed x-ray generator utilizing a triode for biomedical radiography is described. This generator consisted of the following components: a high-voltage power supply, a cable condenser with a length of 10m and a capacity of about 1000pF, a repetitive impulse switching system, a turbo molecular pump, and a pulsed x-ray tube having a cold cathode. The x-ray tube was of the triode type which was connected to the turbo molecular pump and consisted of the following components: a rod-shaped anode tip made of tungsten, a ring cathode made of molybdenum, a ring trigger electrode made of iron and other parts. The trigger electrode was attached to the cathode electrode just inside of the x-ray window and the space between the cathode and trigger electrodes was less than 0.5mm. The anode-cathode (A-C) space was adjusted outside of the x-ray window for controlling the A-C impedance. The cable condenser was charged from 30 to 100kV by the constant voltage generator and was discharged repetitively by the impulse switching system utilizing a frequency control system with a high time resolution. The maximum frequencies varied according to the charging voltage, the condenser capacity which was determined by the length of the cable condenser, and the current capacity of the high-voltage power supply. The frequencies of this generator were less than 100Hz, and the pulse widths of the pulsed x-rays were less than 300ns. The time integrated x-ray intensity was less than 5.0pC/kg at 0.5m per pulse, and the effective focal spot size ranged from 0.5 to 3.0mm.
Research For Living Microcirculation High Speed Microphotograph System
Dayue Zheng, Ruiyi Chen, Zhoufang Ge
The paper introduce adopting inner reflecting illumination high speed microphotograph technology, to resolve the living microcirculation research of non transparent carrier. With the aid of microscope the system can photograph clearly the instantaneous flow state of Living cells, and can also get the clear picture under conditions of non-trauma organism body. A effective means is supplied for research the flow and transformation characteristic of living cells. Blood microcirculation as well as haemorheology. The paper states the system's technology specialisty, principle and main faunction, and simply introduce the experiment results.
Application Of Micro-Highspeed Flow Visualization In Study Of Blood Cells Rheology In Vivo
Li Gui-shah, Liang Ni, Lin Yu-ju, et al.
A new experimental method has been developed in study of rheological behaviour of single red blood cell (RBC) in passing through the capillaries in vivo, using the technique of micro-highspeed cinecamera and micro-highspeed video system. It is one of the most important topics in the study of microcirculatory theories that fur-ther understand the deformability of RBC, flow states, velocities and dynamic mechanimi. A micro-highspeed flow visualization system consisted of essential elements: a biological microscope, a highspeed cinecmera with 35 mm film, a highspeed motion analysis system SP2000 (Kodak U.S.A) and a cold-light source etc. We have investigated the rheological parameters of single RBC in vivo in single capillaries which are about 3.3 to 6.9 um in diameters. The RBCs velocities are 0.1 to 0.25 mm/sec, and maximum shear stress on the outside surface of RBC is 13.8 dyn/cml, and maximum extension of RBC is 10.3 um. In aforementioned experiment, the highspeed flow visualization system frequency at 530 frames/sec and 200 frames/sec were used respectively. In addition, the vasomotion of precapillary sphincters have been measured and a complicated coupling phenomena between the RBC and sphincter have also been recorded and analysed. The experiment were performed with intravital hamsters and frogs. The results obtained by this system shown that the method designed by us are an effective tool in the study of rheological behaviour of single RBC in passing through the blood capillaries in vivoz.
Improving The Making Of Powder Of RE-Si Ferroalloy Using High-Speed Photographic Technology
Dayoung Jia, Chunsheng Liu
Because of the increasing application of RE and the need for the injection metallurgy, we have been trying to find out a suitable powder-making technique of RE-Si ferroalloy widely used as additive in steel and spheroidal cast iron. In this paper, the high-speed photographic technology has been used to analyse the different atomizing methods of RE-Si ferroalloy, especially the atomizing method with gas-jetting and quenching method in water. During atomizing, not only has the process of breaking a single molten alloy droplet been photographed, but also the moving track and changing speed of different sizes of particles have been photographed, and then analysed and calculated. Here we have also put forward our opinion of the mechanism of the quenching process in water of RE-Si ferroalloy, providing a theoretical basis for reliable atomizing technique.
Prism Adjustment Analyses On Multi-Branch Image Coincidence Optical System
Yao Wu, Luo Wenbi
This article deals with refieckins prism adjustment properties in a multi-branch optical system when image coincidence is wanted at the joinins plane of the branch lish pathes. By anatxsins an actual optical system of two branches that is assumed in two kinds of conditions, it is known that in order to satisfy the need of observation and measurement, image at the jointing Point is needed to adjust not only light axis deflction and image inclination, but also image surface deflection and parallax. And general methods of adjusting image surface deflection and Parallax are given. These analyses and adjusting methods have practical significience in the image coincidence adjustment in multi-branch opticl system.
Research On The Highest Frame Rate Of High-Speed Videograph With A Channel
Wang Jingping, Lou Wenbi
The frame rate is an important factor of HSV system. But the application of the scape of IEV is Limited by its tow frame rate.This paper researches a variety of methods to rise the frame rate. On the basis of a frame signal recorded on a track we analyse the capacity of the magnetic head tape system in alt and get the result of 800 frames per second. If normal recorder is used to record high speed video signal, you can get 200 frames per second under the condition of 200 scan tines.
The Amount Of Information Of High-Speed Rotating Mirror Photography System
Zhao Yuejin, Luo Wenbi
Based on the Schardin's formula and the camera designing procedures, the expression of amount of information for high-speed rotating mirror photography system is obtained. This paper proposes a new concept of evenness of amount of information and takes the evenness of information as an additional standard which evaluates system quality. It shows that the amount of information depends on the solection of working angle scale and section shape of rotating mirror besides the maximum edge velocity of rotating mirror. As the wide application of high-speed camera, discussion of its designing method and evaluating criterion continually deepen. One of evaluating criterion of high-speed camera is amount of information. Many schlors discuss this problem from fundamental theory. Starting from the designing method, this paper discusses the amount of information and the evaluating criterion, therefore to find better evaluating criterion.
A New Development Of The Method Of Calculating The Approximating Circle In Rotating Mirror Framing Camera
Zhao Yuejin, Luo Wenbi
This paper deduces a formula which calculates two approximating circles simultaneously. With the help of computer and optimum technology, we calculate two approximating circles parameters under the condition of restricting the angle between optical axle of relay lens and reflecting optical axle of rotating mirror, the evenness of photographic frequency and the evenness of magnifying power of relay lens to certain limits. Rotating mirror high-speed cameras have many advantages such as high efficiency, high resolution and convenient for using. Thus the cameras are used in most of high speed process laboratories. In designing this camera, some calculation methods need to be improved. According to the effect of factors on image quality, this paper obsorbs the advantages of a few methods of selecting approximating circle parameters of framing camera and seeks more reasonable ways to determine approximating circle parameters of framing camera. It makes optical axle of relay lens consistant with reflecting optical axle of rotating mirror in working angle, and also makes the out-of-focus between approximating circle and practical image plane as small as possible. Thinking above two aspects and considering the evenness of photographic frequency and the evenness of magnification of relay lens, this paper deduces the relations between relay lens approximating circle and focal plane approximating circle by using relay lens imagery. By using the method of determining two approximating circles simultaneously, it increases image quality of image point in axle and off axle.
Application Op Ir-Photorecorders Based On Ionization Chambers For Past Processes Investigation
V. V. Egorov, V. P. Lazarcliuk, V. M. Murugov, et al.
There are given the research data of photographic systems characteristics based on the ionization-type semi-conductive chambers (ITSC) with photodetectors of different types. The recorder dynamic range of 103,speed of response of 10-8s, resolution of 10 lines/mm and sensitivity of . 10-4-10-7 J/am2 In 1-10,6 )μm spectral range were obtai ned by optimizing the photodetector parameters,.the chamber design and its operating mode. Energy distribution in beams of pulsed HF and DF chemical lasers in the mode of "magnifying glass of time" was studied using ITSC. It is shown, that the energy distribu-tion on the lasers end has larger irregularity (,102 times) than at the integrated survey. The information has been received about space - time responses of CO2 lasers radiation with the aid of ITSC, operating in a modulation mode of emission at the chamber input,and on the chamber electrodes there is applied pulsed supply voltage with a photography frequency of 20-100 Hz. There are given the results of recording with ITSC of the heat fields structures of different objects over a temperature range 600-2000°C, which are heated by a shock wave or fly at the supersonic velocity at the frame exposure time of 10-10-5s.
Signal And Noise Properties Of Proximity Focused Image Tubes
Richard J. Hertel
Image intensifier tubes amplify an input photon image but, at the same time, reduce its signal to noise ratio due to quantum losses and additive noise. Ouantum losses occur at the photocathode, microchannel plate, and phosphor screen. Additive noise examples are scattered light, photocathode dark emission, and MCP self emission. Uncorrected fixed patterns associated with the MCP fiber optic faceplates plus MCP saturation properties set upper limits on output SNR.
Streak Tube Modulation Transfer Functions
Adam Whiteson
An exponential model is proposed for streak tube MTFs (modulation transfer functions) based on line spread function measurements. This model is used to derive performance characteristics such as temporal resolution, channel width and pixel size. These results are compared with those predicted by a Gaussian model for the MTF.
A New Streak-Tube Design With A High Signal-To-Noise Ratio And Fast Time Response
Mark W. Bowers
A new streak tube is in the preliminary design and review phase. Modeled after the newly designed microchannel-plate (MCP)-based x-ray-framing camera at the Lawrence Livermore National Laboratory (LLNL), this streak tube incorporates an MCP at the light input to amplify the signal before noise is introduced into the system. The signal-to-noise ratio of the streak tube is directly dependent on the gain setting of the MCP and can thus be greater than 1000:1. Temporal resolution will be about 30 ps, and the dynamic range should be greater than 500:1. Another tube of the same design, but employing a photocathode instead of the photocathode/MCP combination, has been studied briefly. With some minor modifications, it should be possible to achieve a dynamic range of about 20 with this version of the design, and to reduce the magnification to about 1 and improve the time response to 150 fs.
Stability And Accuracy Of The Sweep Rate Measurements For LLNL Optical Streak Cameras
D. S. Montgomery
Precise pulse shaping is vital for present and future high-power lasers that will attempt to achieve low-entropy laser-fusion implosions. Multichannel, streak-camera-based systems are used to make such measurements. Such systems must be accurately calibrated in order to correct for time-base and flat-field variations. We use an on-line calibration system in order to measure the sweep rate, and in our recent work we have evaluated the accuracy of this measurement technique. By analyzing a large number of calibrations, and the effect of noise on our measurement technique, we have concluded that the sweep rate for our streak camera systems is reproducible to at least ±1.2% and that our measurement technique contributes an additional ±0.5% uncertainity in the measurement.
The Effect Of Microchannel Plate Intensifier Electrostatic Focusing Fields On Modulation Transfer Function
Roger M. Estrella, Stan W. Thomas
We have determined that the modulation transfer function (MTF) of a microchannel plate intensifier (MCPI) is a much stronger function of the electric focusing field in the screen region than it is in the cathode region. For approximately equal percentage increases in the electric fields, the screen MTF improves about ten times faster than the cathode MTF at 15 1p/mm. Testing was done on three ITT F4111 MCPIs using a computer-controlled EG&G Gamma Scientific C-11 Spatial Scanning System and an impulse line measuring technique with a three-micron slit target contacting the fiber-optic input of the tube. The MTF was calculated using the Fast Fourier Transform algorithm.
Phosphor Non-Linearities In Picosecond Streak Cameras
S. Majumdar, Samprasad Majumdar, Yuri Serdyuchenko, et al.
Phosphor nonlinearities in streak cameras are evaluated by experimental photometric calibration of streak tubes and other image intensifiers by using optical pulses of duration 100ps, 10 ns amd 10 ms. The results confirm that there is a serious loss of efficiency of the phosphor when excited by electron pulses of duration 10 ns or shorter. P-11 phosphors showed an efficiency of 1.85% at 100 ps while P-20 phosphor showed 1.2% efficiency at the same temporal excitation. At 10 ms excitation, the efficiencies were 7.41% and 7.47% respectively. The phosphor efficiencies for short pulse excitation remained unaltered at this low value for intensity levels ranging over four decades.
A Nanosecond Streak Camera With Simplified Streak Tube
Jia Xinzhi, Li Jitian, Niu Huihui, et al.
In this paper, a newly developed nanosecond synchroscan streak cam-era system with simplified streak tube is introduced. A cavity-dumped dye laser is used as a light source of the system. Time resolution of the system is 2 ns and measuring range is up to 30 ns.
Model BGW-1 Instantaneous Pyrometer With An Image Converter Tube
Dalun Xu, Wenqin Cao, Baochang Zhao, et al.
The principle of measuring temperaturr,system design,main characteristics and experiment result of the instantaneous pyrometer are described in this paper. As new techniques of image converter tube having output optical fibre faceplate,contact photography and self-adaptative delayed system were used in the instantaneous pyrometer, it has the advantages of high image clarity and precise logical control.
Theoretical Analyses And Design Considerations Of A Picosecond Framing Tube
Y. Liu, W. Sibbett, D. R. Walker
To further improve the dynamic performances of picosecond-resolution framing cameras, a theoretical analysis has been accomplished which can simulate the dynamic trajectories of photoelectrons travelling through the entire image tube. It is shown that for the exsisting Picoframe-type camera design the spatial resolution is significantly degraded by the lensing effects of the deflectors during the dynamic framing operation. It is also shown that the minimum exposure 'frame' time for X-ray applications is limited by the reduction of the number of photoelectrons reaching the phosphor screen due to the high secondary electron energy spread. A new design of framing tube incorporating either conventional deflectors or travelling-wave deflectors has been developed. In this design, the electrostatic focusing lens has been optimized for better beam quality and higher deflection sensitivity. The defocusing effect induced by conventional deflectors has been eliminated by (i). incorporating an extra cylindrical lens into the deflection section of the tube or alternatively (ii) by utilizing travelling-wave deflectors. The theoretically predicted frame time is about 60ps(FWHM) when using conventional deflectors and less than 50ps(FWHM) with the travelling wave deflectors. The implied spatial resolution referred to photocathode is 10 1p/mm for X-rays and exceeds 15 1p/mm for UV and visible radiations.
Four-Frame UV/X-Ray Picoframe II Framing Camera
W. Sibbett, D. R. Walker, W. E. Sleat, et al.
Electron-optical framing cameras having X-ray/XUV photosensitivities and which can provide a sequence of framed images in the subnanosecond regime are of major relevance and importance to the quantitative monitoring of the kinetics of laser-produced plasmas. Our Picoframe family of framing cameras which has been developed comprise specially designed image tubes that permit the recording of single or multiple frames in the picosecond domain. For instance, an experimental UV-sensitive Picoframe I camera system has been demonstrated to have temporal and spatial resolution of 100 ps, 8 1p/mm in single frame format and 250 ps, 8 1p/mm in a double-frame format having an interframe period between 1.5 ns and 2ns. In this presentation we will describe a double-aperture Picoframe II version of this camera and details will be given in respect of the performance of a demountable, UV-sensitive system. Particular emphasis will be devoted to its operation in a four-frame image format where the generation and implementation of appropriate deflection voltage profiles are especially significant. Experimental data will be presented to show that four discrete frames can be recorded with a frame period of 230 ps, interframe time of ns and a dynamic spatial resolution (referred to the photocathode) of 7 1p/mm. This spatial resolution was retained over the entire area of the 6 mm x mm image geometry at the photocathode. Such a UV-sensitive camera can be readily adapted for operation in the soft X-ray spectral region, as previously reported for the Picoframe I counterpart, and some of the projected performance characteristics will be discussed.
Modeling And Measurements Of Sub 100 Ps Gating With Microchannel Plates
P. M. Bell, B. A. Hammel, J. D. Kilkenny, et al.
Modeling the x-ray gate time of 0.25 mm thick microchannel plates predicts gate times less than 50 ps can be achieved. Measurements of the gate time of these thinner plates shows agreement with the modeling.
Gated Microchannel Plate Framing Camera
K . Kinoshita, Y. Inagaki, T. Nakamura, et al.
A high sensitive framing camera with direct read out has been developed using the framing tube, which incorporates a large diameter microchannel plate, and a 1000 x 1018 cooled CCD camera.
Multiframe X-Ray Images From A Single Meander Stripline Coated On A Microchannel Plate
P. M. Bell, J. D. Kilkenny, G. Power, et al.
The electrical gating of microchannel plates can produce shutter times shorter than 100 ps. Previously, several different micro strip lines with independent electrical gating have been coated on a microchannel plate in order to obtain several image areas on one microchannel plate. We describe here design considerations and results from a microstrip line coated as a meander on a microchannel plate, from which 14, 100 ps images, gated at different times are obtained from a single gate.
Enhancement Of Microchannel Plate Gain By Deposition Of CsI On The Channel Walls
G. Power, R. Bonner
At LLNL microchannel plate (MCP) detectors of x rays have been in use for several years. The voltage is applied by a coating on the MCP which needs to be thick enough that the propagation losses are small. To enhance the gain loss of a thick Au coating CsI is used to enhance the gain and quantum efficiency of the MCP. We have recently discovered that thick coatings of CsI (2 gm) in both the front and back side of the MCP (normal to bias angle) greatly increases the gain.
Temporal Characterization Of A Streak Camera In Synchroscan Operation
B. Cunin, F. Heisel, J. A. Miehe
The system performance of a synchroscan streak camera is discussed in view of (i) the instabilities of the oscillator driving both the laser mode-locker and the camera sweep circuit, (ii) the fluctuations of the period of the incident synchronous and repetitive light pulses. Temporal and spectral analysis of randomly time and amplitude modulated equidistant sequence of light pulses is carried out. The interpulse time jitter of the light beam represents the major contribution to the degradation of the temporal resolution of the synchroscan camera.
Ultranac - A New Programmable Image Converter Framing Camera
B. R. Garfield, M. J. Riches
Development of an image converter framing camera with the feasibility of operation at frame rates of up to 50 million frames per second with up to 24 frames per cycle is described. The camera incorporates a recently developed all metal/ceramic image converter tube which is manufactured 'in house' by the vacuum transfer processing method. All solid state electronics are used to drive the image converter tube whilst individual exposure and inter-frame times are fully programmable. All camera functions can be readily selected and controlled via any standard personal computer.
The Los Alamos Bright Sources: Review Of The Physics And The Diagnostic Technology
G. A. Kyrala, G. T. Schappert, L. A. Jones, et al.
The investigation of many interesting physical phenomena in nature requires the generation of high-energy-density fields. To produce energy densities exceeding 107 J/cm3 requires focusing a very powerful, very bright, short pulse laser. This talk will present a review of the physics that will be investigated with one such laser system, will describe the laser used, will describe the laser diagnostics, and will describe the physics diagnostics. The talk will emphasize the areas of research that will help the diagnostics of different aspects of these bright sources, and their interactions, especially the diagnostics of hot small volumes in picosecond time scales.
Air Breakdown Photography In The Picosecond Domain
G. A. Kyrala, P. H.Y. Lee, K. A. Stetler, et al.
We have studied the breakdown of air using the Los Alamos Bright Source KrF laser at an irradiance of 1.36x1016 W/cm2 and pulse length of 700 fs. Results of the temporal evolution of various regions of the spark, recorded with an S-20 streak/framing camera, are presented.
Application Of Streak Cameras In Sub-Picosecond Photometry Of Emission From Diode Lasers
Shom Majumdar, Yuri N. Serdyuchenko
A high gain and time resolution streak camera calibrated for photometric measurements in the visible to near infrared region of the spectrum was used to show that it is possible to measure single photo-electrons without noise. This camera was used to measure 0.9 picosecond laser pulses from a commercial diode laser emitting at 785 nm. As the instrumental time resolution of the streak camera was 0.80 picoseconds, the deconvolved laser pulse duration was estimated to be below 0.5 picosecond. This is the shortest current driven, gain switched laser diode output pulse yet reported. The detection was linear and without any loss of time resolution for a signal intensity equivalent to 150 photo-electrons per rsolution element on the streak camera output.
Sampling Optical Oscilloscope Using A Traveling-Wave Semiconductor Laser Amplifier
Y. Tsuchiya, S. Aoshima, A. Takeda, et al.
Optical sampling with a traveling-wave semiconductor laser amplifier driven by short electrical current pulses is experimentally investigated for the purpose of designing a simple, compact and sensitive solid-state sampling optical oscilloscope.The temporal resolution of about 350 ps with the chip gain of 10 dB is demonstrated. The minimum detectable power is about 45 nw, which corresponds to input optical energy less than 0.01 fRpuise. The larger chip gain of 23 dB with aperture time of 110 ps for optical sampling is obtained if the laser amplifier is driven near the dynamic threshold level, however unexpected output signals where the intensity variation is inverted are observed.
Non-Contact Picosecond Electro-Optic Sampling Utilizing Semiconductor Laser Pulses
S. Aoshima, H. Takahashi, T. Nakamura, et al.
Non-contact picosecond electro-optic sampling utilizing semiconductor laser pulses, which is compact, easy to use and inexpensive, is described focusing on the recent improvements such as reduction of system noise, adoption of a longitudinal E-0 probe and its advantages, monitoring system of the measurement point, and improvement of the space dependent sensitivity. We demonstrate the equivalent input noise of 125mV/IHz with a temporal resolution of 45ps at a distance of 20gm between the probe tip and the device under test, with a 4.5s measuring time. We also discuss the possibility of absolute voltage measurement.
Optimization Of Parameters For A CPM Femtosecond Pulse Laser
Shui Cai Wang, Ke Shi, Jin Xing Cai
This paper reports optimization of the parameters of a colliding pulse mode-locked (CPM) femtosecond pulse laser including compensation of the dispersion. Our analysis based on the CPM laser dynamics. Seven parameters in the suitable value range have been selected. By using statistics law, we optimized eighteen optimal conditions of the laser operation from thousands conditions. Each laser operation corresponds to certain compensation of proper chirp and group-velocity dispersion, so that the optimum conditions are obtainted for a femtosecond laser with self-phase modulation, group-velocity dispersion, saturated gain and unsaturated gain, saturated absorption and unsaturated absorption. The optimization results also show that the pulse duration can be directly reduced to -10fs by properly increasing the unsaturated gain and the dynamics self-equilibrating capability of dispersion compensation.
Photometric Calibration Of Optical Streak Cameras
V. Platonov, Y. Serdyuchenko, S. Majumdar, et al.
Measurements have been made on optical streak cameras to determine: (a) The streak camera sensitivity in static and dynamic modes (b) The dynamic range in static and dynamic modes (c) Absolute photometric calibration of the system (d) The relative system sensitivity between film and CCD detectors as the recording medium. cw lasers and picosecond pulsed lasers were used as light sources for these measurements.
Integration Of A Gated Microchannel Plate Detector Into The Nova Laser System
J. D. Wiedwald, R. L. Hanks, G. L. Tietbohl, et al.
In recent years the measurements of Inertial Confinement Fusion (ICF) target dynamics using x-ray imaging have grown in both quality and quantity. One instrument being used increasingly at the Lawrence Livermore National Laboratory's Nova facility is the Gated X-Ray Imager. This imager uses a microchannel plate as detector, amplifier, and gating element to allow x-ray photographs with aperture times under 100 ps. In anticipation of as many as 16 imagers installed on Nova within the next year, an electronic control system has been developed. This system simplifies operator interface when in a "stand-alone" mode while synchronizing with the Nova sequence clock when in the "shot" mode. The system is also expected to be fully integrated into the Nova computer system within the next year. This will allow remote parameter input and the monitoring and archiving of system status.
Autocorrelating Streak Camera System
J. Stephen Baumgart, Robert Justice
The integration of a streak camera with a one-shot autocorrelator creates a novel diagnostic system. This system can measure optical pulse widths of successive pulses in a laser pulse train, where the pulse width is a very small fraction of the train length. The integrated system has a temporal resolution of better than 250 fs and can measure about 80 pulses separated by a minimum of 15 ns. This paper describes the nature of the optical signal that was to be measured and out-lines the performance goals of the system. The hardware configaration and theory of operation are also described. Laboratory data are included to show the system's sensitivity and resolution. Finally, recommendations for system improvement are discussed.
Streak Camera System For Prompt Display Of Laser Pulses
J. Stephen Baumgart, Robert Justice
The streak camera's high bandwidth and large capacity for carrying information make it a highly flexible data recording tool for imaging experiments. This paper describes how a streak camera system was used to make two-dimensional measurements of a pulsed laser system, the Free-Electron Laser (FEL), to aid operators in tuning the laser. The streak camera system measured beam position, full width, relative intensity, and shape on multiple pulses in a single sweep. These measurements were analyzed in real time and the information displayed immediately for the operators' use.
Pulse-Shape Measurements On OMEGA
P. A. Jaanimagi, R. Saunders, C. Hestdalen, et al.
Direct-drive laser fusion targets require that the irradiation nonuniformity be in the range 1-2% σThis This implies that UV power imbalances between the 24 beamlines of the OMEGA laser system need to be measured to a precision of order 1%, i.e., the system signal-to-noise ratio must be in excess of a few hundred. In this paper we report on the feasibility of making such measurements with a 24-channel streak-camera system.
Picosecond Streak Camera Measurements Of Short X-Ray Pulses
M. M. Murnane, H. C. Kapteyn, R. W. Falcone
A commercial x-ray streak camera was modified to obtain an impulse response of 2.5 psec. It was used to measure the x-ray emission from a plasma produced by a sub-picosecond laser. An upper limit of 1.5 psec was obtained for the x-ray pulse duration over the 50 eV to the 1 keV region of the spectrum.
SBS Pulse Distortion In Multimode Optical Fibers: Preliminary Results
J. R. Smith, R. J. Hawkins, C. W. Laumann, et al.
We have observed severe temporal-pulse-shape distortion due to stimulated Brillouin scattering (SBS) in multimode optical fibers used to diagnose 351 nm laser pulses on the Nova laser system. Our measurements can be fit by a basic model of SBS and provide a clear indication of the intensity and temporal regimes where significant SBS-induced temporal-pulse-shape distortion can be avoided.