This paper gives a brief survey on some major developments on highspeed photography and photonics in China. History and organisation thereon are shortly reviewed. The technological aspects are illustrated by various kinds of cameras and devices developed and manufactured, such as the category of opto-mechanical cameras, the image converter and streak cameras, highspeed holography and interferometry, ultra short optical pulse etc. Some technical data are given to indicate their technical levels achieved. Examples of applications are also given to show their utilisation in various field of national construction as well as in scientific research.

In the past decade, high speed photography has been rapidly incorporating electrooptics. More recently, optoelectronics and digital recording of images for specialized laboratory cameras and commerically available systems have helped broaden the versatility and applications of high speed photography and photonics. This paper will highlight some of these technologies and specialized systems.

A brief historical review of temporal-analyzing image converter tubes(ICT) development in our country is presented. Some recent results in designing and manufacturing of the tubes capable to operate in visible, near infrared, ultraviolet and soft X-ray spectral regions are given. There is a great variety of the available image converter tubes which provide pico and femtosecond temporal resolution in circular, single streak and synchroscan mode of operation, as well as picosecond resolution in single and multiframe photography. High technical parameters of the created tubes ensure their successful application for high speed events recording in laser and plasma physics research, solid state and semiconductor physics, nonlinear and fibre optics, microelectronics and optical computing, laser ranging, mind/brains imaging, and so on. Further directions in designing of completely new type of temporal-analysing image converter tubes, will be outlined, while the special attention will be drawn to the tubes with the electron beam sensitive CCD detectors.

State-of-the-art picosecond and femtosecond pulse lasers for which optical nonlinearity in extracavity or intracavity/coupled-cavity configurations has been exploited are reviewed. Particular implications with regard to electron-optical streak camera diagnostics have been indicated where appropriate.

The "Centre d'Etudes de LIMEIL-VALENTON", since 1962, has maintained a continuous effort in the developpement of all techniques involved in Laser-Plasma Experiments. This includes not only laser technology but also diagnostics studies and targets design and fabrication. Among the different kind of diagnostics currently used are High Speed Streak Cameras, fast Oscilloscopes and detectors sensitive in the I.R., visible, the U.V. region and the X-rays. In this presentation we will describe the three high power lasers which are still in operation (P 102, OCTAL and PHEBUS) and the main diagnostics used to characterize the plasma.

The application of laser power densities above the plasma ignition threshold to any dielectric, semiconducting or metallic target material is capable of providing a most efficient energy transfer by an enhanced coupling mechanism. The present paper is concerned with experimental investigations of pulsed laser target interaction phenomena in a medium power density range below air breakdown threshold. When infrared lasers are considered, these values are in the range of some hundreds of MW/cm2 or even below, for UV-lasers these values may be higher by one or two orders of magnitude. This range is of particular interest, as plasma induced thermo-mechanical processes are governing and improving the energy transfer. Many of the processes involved have been investigated for single pulse operation. The most interesting features are occurring, however, if trains of pulses are applied, thereby building up high average power densities so that target effects are integrated. temporally. These effects are then increasing rapidly giving rise to fast heating, melting, vaporization and subsequent ablation, including thermally induced chemical reactions. The paper gives an overview on current research in the above mentioned field and describes recent measurements performed at the ISL Saint-Louis. Main emphasis is layed on discussing the various types of fast electrical and optical diagnostic principles and techniques used for the optimization of the energy transfer rates at this particular high average power density range.

We have made a nanoseconds framing camera with the second generation image intensifiers and have photographed the images of 5 ns framing time with GZ2-2030T image intensifiers. The resolution is 10 1p/mm. The photographable photo-dynamic region is 100 times. The shutting action is achieved by appling a -800 V gating pulse to the quiscently zero-biased MCP input--output interface. Gating speeds and the quiescently bias influnce on them, the maximum photographable photo-dynamic region, the spatial response of the phosphor screen for uniform photo-cathode illumination have characterized. The characterization system,gating and bias-ing circuit will be presented.

In this paper, a new picosecond synchroscan streak camera system, including our own synchroscan streak image tube, RF streak circuits and CPM laser system, has been reported. The temporal resolution of the streak image tube itself was 300fs and spatial resolution was 50 1p/mm. The dynamic sensitivity of deflection was 10cm/kV and factor of merit was greater than 100, which decreased the requirement of the RF deflection power to the streak circuits. Our RF streak circuits consisted of PIN diode, electric second harmonic selector, pre-amplifier, power amplifier and impedance matching unit, which gave maximum RF power of lOw and operation frequancy of 200MHz. The CPM dye laser system developed in our laboratory was pumped by an Ar? laser system and presented the shortest pulse duration of +5fs and repetation rate of 100MHz with acceptable stability. The preliminary experiments showed that the temporal resolution of 2ps of the whole camera system was obtained which was limi-ted by the stabilities of above laser system and RF streak circuits.

A series of Anglo-Soviet picosecond streak/synchroscan cameras was designed for application in various branches of science and technology. We are analyzing some of the most important steps in arranging of this joint camera production as well as briefly discussing further directions of our activity. Dynamic tests of mutually developed streak/synchroscan cameras are described.

The paper has pointed out that the electron transit time dispersion is much worse in the case of the quad tail energy distribution (QTED) typical of x-ray photocathodes in the photo-cathode to mesh region of picosecond image tubes. The temporal abberations of a whole tube have been calculated on condition of a spherical photocathode and concentric a spherical mesh. The paper has put forward a principle of the temporal compensator for the purpose of obtaining the limiting time resolution (about 10-14sec. for the visible light) of image tubes and abolishing the grid mesh which effects seriously the processing of high sensitivity photocathode. It is a electron pulse compressor in essence and has the same action as the mesh.

Described are the comparative testing of two type of electron-optical recording instruments, namely, TDS simplified streak device designed and manufactured at the Centre of Scientific Instruments, GDR Academy of Sciences, and anglo-soviet Imacon 500 picosecond streak camera fitted with PV-001 tube. The Imacon 500 streak camera was matched with a SIT vidicon readout system. Temporal resolution, dynamic range and input sensitivity were estimated for the same recording conditions. It was shown that for 6 ps laser probe pulses the TDS dynamic sensitivity at 530 nm input radiation is only four times less comparative to the commercial Imacon 500 system, while both systems have almost the same dynamic range.

In our specially designed femtosecond streak image tube, the electron beam was focused by a cylindrical electron optical lens. In order to achieve temporal resolution of less than 50fs and large dynamic range, the electric field near the photocathode was 6-8kV/mm with a slit acceleration electrode. The temporal dispersion in our lens has been eliminated completely by optimization of the electron focusing lens. To compensate the temporal dispersion arising from photocathode to accelerating electrode, a compensation element and a half open aperture have been introduced, so that the total temporal dispersion of less than 50fs has been achieved. To overcome the influence of a strong fringe field of the deflector in dynamic mode on the total temporal dispersion and spatial resolution, a travelling wave deflector will be used. In addition, to minimize the space charge effects, the electron transit time in this specially designed electron optical lens was shortened to 840ps and the so called crossover in slit direction disappeared. The discrete space charge effects have been modeled by Monte Carlo method including photoelectron emission process and induced charge on the electrode. The calculations have shown that this tube can handle the current density of up to 20A/cm2 without deterioration of the temporal resolution.

A nanosecond single frame camera by gating the 25mm proximity focused microchannel plate (MCP) intensifier has been developed at our institute. On the basis of previous researches on proximity focused microchannel plate intersifier tube (MCPT) for gating application, it has been payed more attention in this programme to developing a commonly used camera with gating time < 10 ns. The structure of the camera, the MCPT for fast gating application, the gating pulser and the way to connect the pulser to the MCPT are presented. The characteristics of the camera are discussed. When the tube is gated by a 2 ns FWHM driving electrical pulse, measured resolution is 4.7 1p/mm.

This paper has mainly discussed the design aspects of an optical system for a femtosecond streak tube camera. The optical system produces the negative temporal distortion of 3.5 ps at the maxmum visual field, so the positive temporal distortion of a fs streak tube can be remedied, it results in that the temporal distortion of the whole system has been less than 50 fs. In addition, it can be used for three wave ranges depending on the light source.

The paper reports on the design of an ICI camera operating in the mode of linear or three-frame image scan. The camera incorporates two tubes: time-analyzing ICI PIM-107 1 with cathode S-11, and brightness amplifier PMU-2V (gain about 104) for the image shaped by the first tube. The camera is designed on the basis of streak camera AGAT-SF3 2 with almost the same power sources, but substantially modified pulse electronics. Schematically, the design of tube PIM-107 is depicted in the figure. The tube consists of cermet housing 1, photocathode 2 made in a separate vacuum volume and introduced into the housing by means of a manipulator. In a direct vicinity of the photocathode, accelerating electrode is located made of a fine-structure grid. An electrostatic lens formed by focusing electrode 4 and anode diaphragm 5 produces a beam of electrons with a "remote crossover". The authors have suggested this term for an electron beam whose crossover is 40 to 60 mm away from the anode diaphragm plane which guarantees high sensitivity of scan plates 6 with respect to multiaperture framing diaphragm 7. Beyond every diaphragm aperture, a pair of deflecting plates 8 is found shielded from compensation plates 10 by diaphragm 9. The electronic image produced by the photocathode is focused on luminescent screen 11. The tube is controlled with the help of two saw-tooth voltages applied in antiphase across plates 6 and 10. Plates 6 serve for sweeping the electron beam over the surface of diaphragm 7. The beam is either allowed toward the screen, or delayed by the diaphragm walls. In such a manner, three frames are obtained, the number corresponding to that of the diaphragm apertures. Plates 10 serve for stopping the compensation of the image streak sweep on the screen. To avoid overlapping of frames, plates 8 receive static potentials responsible for shifting frames on the screen. Changing the potentials applied to plates 8, one can control the spacing between frames and partially or fully overlap the frames. This sort of control is independent of the frequency of frame running and of their duration, and can only determine frame positioning on the screen. Since diaphragm 7 is located in the area of crossover and electron trajectories cross in the crossover, the frame is not decomposed into separate elements during its formation. The image is transferred onto the screen practically within the entire time of frame duration increasing the aperture ratio of the tube as compared to that in Ref. 3.

A numerical assessment of the role of phase noise in the synchroscan deflection signal and its effect on achievable streak camera temporal resolution is detailed and tested experimentally. The circuitry employed in the synchroscan streak operation of the Photochron IV camera system is described. The experimental performance of two synchronisation systems, (i) a passive configuration whereby the deflection signal is derived directly from a mode-locked pulse source and, (ii) an active system incorporating a tunnel-diode oscillator phase-locked to the laser, have been experimentally compared. By taking phase noise into account the circuitry has been appropriately optimised and this has permitted the demonstration, in synchroscan mode, of a limiting temporal resolution of 930 fs for the Photochron IV synchroscan-camera. Techniques to further enhance this performance and extend synchroscan operation further into the sub-picosecond domain will be outlined.

The age of scientific and technological revolution sets forth the study of high speed processes as a most vital task. Further progress in science and technology and increase of production efficiency are largely dependent upon the use of high speed processes and machines and mechanisms capable of dealing with them.

The film-clawing mechanism in a 300 f.p.s. intermittent camera developed by us is a five-linkage mechanism, an eccentric adjustable loop is added to the rear hinge of the linkage for the double-crank mechanism.

Model XGS-12 high speed motion-picture camera is a new type of 16mm rotating prism camera with high quality. It has been recently developed by our institute. It has optional accessories. The maximum frame frequency of the camera. is 11000fps when one frame size is 7.5 x 10.4mm2. In this paper, three systems of this camera will be introduced, i.e. optical system, mechanical system and electronic control system. 16mm rotating prism camera has become one of indispensable instruments to modern laboratories and experiemental fields, and has widely used as measurement and analysis of high. speed phenomena quantitatively and qualitatively, being portable and cheap instrument, wide range of frame frequency from 10 to 104fps. Model XGS-12 high speed motion-picture camera. has been recently developed by our institute. It is another new kind of 16mm rotating prism. camera. Now, it is being intro duced as follows.

Synchronisation is an essential component of any high speed photographic experiment to combine the three principal components - subject, camera and lighting. Today there are many available equipments to ensure synchronisation for the current industrial and research problems but when the exception occurs, the skill of the good researcher again becomes necessary. It was not until the manufactured plates and films became available in the 1880's that high speed photography became a real tool and the early users had to solve their own timing problems. In general the early techniques were relatively simple but quite effective. Muybridge in his "Animal Motion Studies" arranged that the subjects operated the cameras by cords to the lens shutters. This was extremely effective. But a few researchers wished to look at very rapid events and needed more automatic methods. For example Mach began on photographing bullets and shells requiring timings in the microsecond range. Because he and his collaborators always took photographs and his reputation was so great, his work was always noted and assumed to be original. Some thirty years earlier, in Berlin, Toepler and Holtz under Professor Riess were working on Electrostatic Generators and Sparks which led Toepler on to his brilliant development of the Schlieren technique. His early application of this technique involved the synchronisation of two spark gaps, one as an illuminant and the other as an event such that shock waves were made visible by his Schieren system. The "pictures" in his published papers look like photo-graphs but in fact were engravings from his own drawings after viewing at least hundreds of images. His circuits and the later Mach circuits must be the earliest of our modern electronic circuits and fully deserving of our recognition.

This continuous-access rotating drum/rotating prism type camera has proved itself in the auto industry as a fixed-position instrument. The commercial version features an integrated film supply, a sector shutter and interchangeable optical and video viewfinders. The framing rate has been increased to 1000 fps.

The description of the main performance, general outline, specifications of design and application are given in this paper. Some typical pictures of test taken by this camera are presented.

This paper depicts the development and test of Model P-302 Beryllium Rotating Mirror Component used in Model WPG-30 or Model SJZ-15 Streak Camera. The mirror body is made of Hot lsostatic Pressing (HIP) Beryllium. The mirror reflective surface is made by replica film method and consists of 0.1 wave-length flatness beryllium substrate with an aluminum overcoating. Its reflectance is 83%. The cavity of the rotating mirror is not vacuumized. The rotor is strictly adjusted with the dynamic balance method. The turbine is driven by compressive-air and the maximum rotating speed in test is 5,833 rps. The size of the mirror body is 22.5X25 mmX8 mm (rotating diameter is 22.5 mm). Under examination of dynamic performance its writing rate is 15 km/s, the time resolution is 1.4 ns (0.01 mm slit width), the dynamic resolution in scanning direction is 28 line pairs/mm and the effective aperture at film is 1/10.6. The results for detonation experiments indicated that when its rotating speed was 5,000rps, the image density was suitable for measurement while using 36 DIN film. And the results also showed that the precision of measurement have been greatly improved as compared with the steel rotating mirror used before.

The general microprocessor control console described in this paper can be used for two kinds of high speed rotating-mirror camera driven by turbine or by motor. Its technical specifications, component parts and performance are expounded. The trial tests show that the control console is characteristic of high accuracy in r.p.m. measurement, stable and reliable in operation and easy to be operated and maintained.

Time synchronizing problem is an important problem in high speed photography. In order to solve this problem, a multifunctional synchronizing control system has been developed. This paper introduces structural principle of a multifunctional synchronizing control system and its applications in range test. This system is mainly applied to synchronizing photography which controls high speed cameras in measurement of trajectory and armor penetrating process, and may be also applied to synchronizing control in other time-seguential operations. This system has been used in range test to control one ZDF-50 rotating-mirror and two XG-1 slit high speed cameras, at the same time, to take pictures of 12.7mm antiaircraft machine gun bullets.

This paper deals with a new type of control system for a continuous access rotating-mirror high speed camera. New design of most circuits and the fast-open shutter of the system has been adopted. The control system has characteristics of stability and reliability, accurate controlling, and rather high integration and automation. The system has been used for Model ZDF-180 rotating-mirror high speed camera, with satisfied operational results. In the study of high speed phenomena, such as explosions and discharges, etc., the continuous access rotating-mirror high speed camera is an indispensable photographic recorder. With wide applications of high speed photographic technique, the environments where this camera is used are more complicated so the following performances of the controlling sys-tem are required to be further raised: 1. the control accuracy of the system (synchronous accuracy and measuring accuracy of photographic frequency); 2. the opening speed of the fast-open shutter, so as to guarantee enough effective recording time; 3. the ability of anti-interference. The control system is made to be more stable and reliable; 4. the improvement of performances of the system by adopting new components, so it is more handy to be operated. In order to meet the requirements mentioned above, a control system has been designed. It consists of three parts: the main control, the fast-open shutter and its control, motor control driven by the rotating-mirror. The principle block diagram and working process of the each part are introduced separately as follows:

In this paper, the results in test of high-speed rotating mirror and its applications were described. Some problems and their solvents that the rotating mirror meets at high-speed were introduced. As a result, four kinds of rotating mirror devices were given. High-speed rotating mirror device is mainly composed of rotating mirror, support system of mirror and driving system. They would be mainly studied.

In this paper the theoretical analysis of a phased roller movement is made. A numerical method for calculating kinematic characteristics of the film and a numerical method for calculating eccentric radii of the rollers according to the required working angle of the movement are introduced. The results of the calculation and the shooting experiment of a prototype camera, containing such a movement, are introduced, too.

Frition driving by elastic sleeve is a novel driving mechanism, and has been recently developed in China and other countries. FSMDES has compact mechanism, resonable pressure method and other suitable to high rolling speeding driving. Up to now, there have not been special theoretical study for this mechanism. But more heavy and complexity. It can not be used in practice calculation. So in this thesis a simple approximate calculation be deduce based on theory of bent staff for thin and thinless sleeve. In all Parameters of elastic sleeve in practice, comparaing the calculation of approximate model with the results of finite element method and theoretical method on sleeve, there are very agreement and more high precision for the approximate calculation model. This calculation model can be used to calculation the deformation of elastic sleeve in practice.

This multi-function waiting type high speed camera can be used for either waiting type or synchronizing type, it can also be used as high speed streaking, framing, shadowgraph or interference photograph. The time resolution of its streaking system is 1.75x10-7 -1.17x 10-9 sec. the steaking speed is 0.0667-10mm/psec. The framing rates of its framing system are 1-150x10 4 pict/sec and 2.25-337.5x104 pict/sec separately. The framing sizes are 14x24mmland 9.1x15.6mm2 separately. This paper descrides the features, working principle, overall design and main technical performances of the instrument.

This paper discusses several problems on the JX-300 intermittent synchronous high-speed camera developed by the Institue of Optics and Electronics (10E), Academia Sinica in 1985. It is shown that when a framing rate is no more than 120 frames/s, a relatively high reliability is obtained resulting from low acceleration of the moving elements, weak intermittent pulldown strength, low frequency vibration, etc. At the time when a framing rate increases to over 200 frames/s, the photographic resolving power, as well as the film running reliability reduce due to the dramatic increase in vibration and pulldown strenth, which is similar to that in the stationary photography. It is getting worse when the framing rate is up to 300 frames/s. Therefore, deliberating on the choice of a claw mechanism having a framing rate of over 300 frames/s and conducting a series of technical measures are particularly important for a camera to obtain a sharp object image securely, otherwise it can hardly reach the framing rate of 300 frames/s for an intermittent camera. Even if this framing rate is attained, the image quality is also deformed and the mechanism would be rapidly worn off from high vibration.

The modulation transfer function (MTF) chain of drum high-speed model GGS-1, particularly, the effect of its natural image displacement and the change of illuminant intensity on image quality are discussed in this paper.

This paper gives: (1) a detailed description of the combined characteristics and the directions for use of the combined laser high-speed camera; and (2) a brief description of the main characteristics of its constituent parts. In the last part of this paper, a special description is given of : (1) the photographic method of finding the rule of flying of the flying chips under the action of explosives by using this instrument; and (2) the related test results.

This paper is a discussion of the development and of the current state of the art in picosecond soft x-ray streak camera technology. Accomplishments from a number of institutions will be discussed. X-ray streak cameras vary from standard visible streak camera designs in the use of an x-ray transmitting window and an x-ray sensitive photocathode. The spectral sensitivity range of these instruments includes portions of the near UV and extends from the subkilovolt x-ray region to several tens of kilovolts. Attendant challenges encountered in the design and use of x-ray streak cameras include the accommodation of high-voltage and vacuum requirements, as well as manipulation of a photocathode structure which is often fragile. The x-ray transmitting window is generally too fragile to withstand atmospheric pressure, necessitating active vacuum pumping and a vacuum line of sight to the x-ray signal source. Because of the difficulty of manipulating x-ray beams with conventional optics, as is done with visible light, the size of the photocathode sensing area, access to the front of the tube, the ability to insert the streak tube into a vacuum chamber and the capability to trigger the sweep with very short internal delay times are issues uniquely relevant to x-ray streak camera use. The physics of electron imaging may place more stringent limitations on the temporal and spatial resolution obtainable with x-ray photocathodes than with the visible counterpart. Other issues which are common to the entire streak camera community also concern the x-ray streak camera users and manufacturers. Optimized spatial and temporal resolution, enhanced dynamic range, and the understanding of shot noise statistics are topics which are being worked on at this time.

The fundamental studies for the triple-flash x-ray generator having variable spectra for biomedical radiography are described. Two types of triple-flash x-ray generators consisted of the following components: a high-voltage generating unit, a voltage divider unit, three high-voltage pulsers, a triple-parallel impulse switching system utilizing air gap pulsers for the main gas gaps, a high-power gas diode having three terminals, a turbo molecular pump, and three x-ray tubes having cold cathodes. For the single-tube generator, the pulse condensers of the pulsers were charged to the same or different energies by using a voltage divider unit and were connected to the x-ray tube through a high-power gas diode. In contrast, the pulsers were connected directly to three tubes without a diode. The duration of each x-ray pulse was a few ps, and the minimum time interval between two pulses was about 100ps (single-tube type), the x-ray intensity was less than lx10-5C/kg at lm per pulse, and the effective focal spot size was determined by the diameter of the anode rod. The triple exposure of pulsed x-rays having variable spectra and time intervals was obtained.

The construction and the fundamental studies for a pulsed x-ray and charged particle beam generator used in the low photon energy region are described. This generator consisted of the following components: a high-voltage power supply, a high-voltage coaxial oil condenser of 120kV-0.2pF, a gas gap switch, a low-impedance coaxial transmission line, a turbo molecular pump, and a pulsed x-ray and charged particle beam tube. The condenser was charged from -60 to -100kV and was connected to the radiation tube through a gas gap switch. The electric charge stored by the condenser was discharged to the radiation tube when the gas gap switch was closed. This radiation tube produced pulsed (flash) x-rays through copper foil anodes. The charged particle beam was produced by the ionized air outside of the anode window due to the production of a high dose rate of x-rays, and these charged particles were accelerated by the electric field between the anode and ground. Both kinds of radiation were produced simultaneously, and the migration time of the charged particles corresponded to the duration of the pulsed x-rays.

A repetitional pulsed x-ray generator in conjunction with an image intensifier system for biomedical radiography is described. This generator consisted of the following components: a high-speed power supply, various capacities of pulse condensers, a turbo molecular pump, and an oil-cooled x-ray tube. The pulse condensers were charged to the optimum voltage of less than 100kV, and the electric charges were discharged repeatedly by using the flashover mechanism. The pulse width tended to decrease when the capacity and the anode-cathode(A-C) space were reduced, and their values were less than 200ns. The current of the power supply determined the repetitional rates for the pulses, which were limited by the charging resistor, the condenser capacity, the charging voltage, and the electric power of the power supply. The maximum value was less than 20Hz due to the ripples of the charging current of 50Hz. The x-ray quality primarily became hard by increasing the charging voltage, and inserting metal filters. The effective focal spot size primarily varied according to the diameter of anode tip, and its size was less than 3.0mm in diameter. Pulsed x-ray fluoro-scopy was performed by using an image intensifier system utilizing a CRT for medical use.

1GW iodine photodissociation laser beam (λ= 1.315pm) is focused to generate continuum X-ray radiation at a titanium (Z=22) target. A piece of aluminum (360Å) on mylar (8μm) film is used to isolate the soft X-ray emitted. Convex - curved mica (2d002 = 19.84Å) crystal spectrometer is used to obtain soft X-ray spectra and the slope of continuum X-ray spectra ( λ < 20Å) are found to show two different effective electron temperatures, 0.11 KeV and 7.1 KeV and we conclude there are two electron groups in the iodine photodissociation laser produced titanium plasma.

In this article we describe the project of a Modern Flash Radiography System being constructed by our Institute. Its main characters are: (1) The Marx Generator for nanosecond pulse has modular construction, similar to products of Hewlett-Packard Company of American, to improve the stability. (2) The inductance of the Marx circuit has been reduced, so the output voltage of this Flash Radiography System will be raised and its volume will be reduced. (3) Multi-stage triggers have been used, which will extend the trigger range of gap switch. (4) Flash X-ray Tube with multi-tip explosive cathode have been manufactured, it will improve dose and life of Flash X-ray Tube. The performances of this improved equipment will catch up with and partially surpass the performances of products of Hewlett-Packard Company.

A flash radiographic system utilizing a single flash x-ray generator having a new kind of combined x-ray tube and a computed radiography (CR) system is described. This system consisted of the following components: two types of delay switches (i. e. (a) direct switching and (b) laser switching), a delayed pulse generator, a CR system, and a high-intensity single flash x-ray generator. This generator consisted of the following components: a high-voltage generator, a high-voltage pulser, a vacuum pump, and a new type of combined remote x-ray tube with two sets of anode and cathode electrodes. When the radiographic object triggered the timing switch, a short electric pulse was produced and was transmitted to the delayed pulse generator. An accurate delayed flash x-ray was produced when the delayed pulse was transmitted to the high-speed impulse switching system inside of the high-voltage pulser. Next, when the radiographic object was exposed to the controlled x-rays under the optimum radiographic conditions, the permeating x-rays produced the digital image. The FX pulse widths were less than 10Ons with a photon energy of less than 120keV. Since the time resolutions for the two types of delay switches were less than 2Ons, the total time resolution for the FX production was less than 1ps. Various kinds of high-speed biomedical radiography, e. g., the continuous delayed radiographs and the continuous three-dimensional analysis could be performed by controlling the radiographic conditions.

XIOPM was founded by Academia Sinica in 1962. The main goal of the Institute is developing some optical and opto-electrical diagnostic tools of transient phenomena. The paper describes the activities of the Institute on developing various opto-mechanical high speed cameras, image converter tube high speed streak and framing cameras, high speed holographic cameras and other high speed cameras and the achievement acquired since its foundation.

As shown in [ 1, 2] , the use of a microchannel plate (MCP) as an electromagnetic radiation photoreceiver has certain advantages over the use of semitransparent metal photocathodes. First, MCPs feature a significantly higher level of radiation conversion, particularly in case of hard quanta. Second, the spectral sensitivity range of MCPs is much wider running from vacuum ultraviolet to the 17-domain. These properties make an image converter tube (ICT) with an MCP photocathode a promising device for registration of high speed processes in a wide spectrum range.

An X-ray image converter tube, type PRM-V, intended for registration of soft X-ray radiation in the 0.5 to 10 Å range has been designed.

In this paper, the principle of the synchroscan streak camera will be discussed based on the Bernuli Theorem, and its equation of detection and the minimum detectable threshould of input light power density will be derived according to the theorem of noise. The limited time resolution of this kind of camera will be dealt with in terms of the method of probability and mathmetical statistics theoretically and it will be estimated with Monte Carlo method accurately. According to above theoretical analysis, the relevant parameter relationship of this kind of camera will be established quantitatively, which will show how to improve the performances of this camera effectively. The calculation results will show that its minimum detectable threshould of input light power density is in the order of 10-12w/mm2 and that its limited time resolution can be better than that of the single-shot streak camera by improvements of stabilities of the CPM laser system and its relevant streak circuits.

A measuring system of instantaneous optical spectra with an image converter tube was described in this paper. The system consists of a wide-band and high-transparent objective lens, the Model WDG-30 spectral head with plane reflection gratings and the Model JTG-305 image converter framing/streak camera. The design consideration of the system, the image converter tube and its control as well as main characteristics of the system were presented.

This paper mainly deals with the present status of the development of nanosecond image converter framing cameras and nanosecond double-proximity image intensifier framing cameras in our country, and discusses shutter pulse generator circuits of these cameras. 1-2 The mixing circuit consisting of avalanche transistor series and pulse thyratron maintains strong anti-interference. Its trigger delay time is 14ns, the trigger jitter is about :500 ps, the shortest output pulse width is 15ns, its amplitude is 550V and the pulse spacing is 150ns. The circuit consisting of avalanche transistor series and rapid restorer diode has 300v of output pulse amplitude, lOns of pulse width and 5Ons of pulse spacing. It is suitable for a new type of image converter tube which is not strict with pulse waveform. But, the strobe circuit of multichannel double-proximity image intensifier camera can provides 2ns of pulse width, 2ns of pulse spacing and -300V of amplitude. When it is used with double-proximity tube, this kind of strobe circuit can obtain a dynamic resolution of better than 4.71p/mm. When it is used for MCP-PMT ns pulse generator, its largest synchronous pulse frequency is 30 kc; pulse width is 4-40ns; adjustable amplitude is 200-300. These circuits can be used for controlling low-light silicon target pick-up tubes, for testing high voltage electric device characteristics, for ns pulse source and laser modulation by improving them slightly. The existing ns image converter framing cameras are limited in their applications, since their framing rates can not be high enough to satisfy the requirements for measuring tran-sient phenomena. In 1982, we developed a ns ring-shaped grating image converter framing camera with an exposure time of 15ns and a frame spacing of 150ns. The reason why these data indexes are not high enough is that the ring-shaped grating image converter tube is very strict with the front and back edges and the flat-topped oscillation of the shutter strobe pulse waveform added to the control-grating of the ring-shaped grating image converter tube. The time of switching devices selected as gate pulses can not be very short. The switching devices are in a state of big current pulse discharging, the restoring time of the tube is longer from leading to stopping, so it is difficult for several gate pulses to form rather short spacing and steep-front and back serial pulses on the same common load. Thus, the dynamic space resolution of the image converter tube does not meet the applied requirements because of the poor gate pulse waveform. The gate pulse generator switching device in this kind of framing camera adopts a mixing circuit consisting of the avalanche transistor series and the pulse thyratron (Fig. 1). The output pulse amplitude of this circuit is 550V, rising edge: 2.5ns, falling edge: 4.5ns, trigger delay: 14ns, jitter: 500ps. It adopts low impedance matched output. As the circuit has advantages of short trigger delay, little jitter and strong anti-electromagnetic interference ability, the satisfied results have been obtained in the test of once-through strong electromagnetic interference.

The term "ballistic detonics instrumentation" is generally applied to all physical observations that occur in connection with the detonation of conventional high explosives. The reaction and/or detonation velocities are of the order of 1000 m/s to 9000 m/s, at pressures of several hundreds of kbar. In order to obtain records or pictures of a detonative event with little motion blur and high time resolution, exposure times of less than 10 ns and frame rates higher than 106/s are desirable. About one or two decades ago, new discoveries and improved knowledge in the field of detonics were heavily dependent upon developments in high speed photography. Nowadays, however, special cameras are available for diagnosing detonation phenomena and events involving high pressure and shock waves, and their commercial development has produced reliable and easy-to-use instruments. Thus, the scientist working on ballistic detonics problems can now concentrate on developing measuring techniques instead of developing measuring instrumentation. A short overview will be given of the different most used and important optical equipments and cameras in the field of ballistic detonics instrumentation. Furthermore various examples of sophisticated, and even "tricky", configurations for optical high-speed mea-surements in the field of ballistic detonics diagnostics will be shown.

The model BY-90 high speed raster motion picture camera was designed and manufactured by authors in 1986. The raster plate that was adhered together by two plates of plano-convex cylindrical lenses has been used. The images were moved by the rotating Nipkov disk. The range of framing rate is from 1000 fps. to l5x10 4 fps. and maximum frame number is 300. It has an electro-magnetic shutter, the control systems consist of model TP-801 micro-computer and other parts for measuring the framing rate, digital display and the shutter release synchromization. On the basis of above-mentioned camera, a new type camera was designed. We have also redesigned the mechanical scanning field in a square shape instead of the circular field. The practical field of square microlenses can be more effeciently used, thus the operating characteristic of this type camera will be improved further.

A new stroboflash photographic system has been developed. The photographic device is a SLR camera with a motor drive, the stroboscope consists of eight strobo-tubes and control circuit. The flash color, flash rate and the flash duration can be changed rapidly by micro-computer on line, so that it is available to measure the track and parameter of moving object. Low cost and versatility is the advantage of this system.

High dynamic performance is required for a cilletheodolite which provides high speed and acceleration tracking and high speed photo-recording and measuring simultaneously,with the development of superfast iissue and the requirelient of measuring at short slant distance. In order to track such fast targets, angular velocities beyond several radians per second and accelerations beyond several radians per second squared are required at the tracker's axes. It is difficult for conventional configuration to achieve high tracking acceleration while keeping small size and unexpenive price. A new type firror tracking system was developed by photosonics, In in 1971.1

In 1938, Steenbeck et al.1 succeeded in constructing the first generators capable of delivering intense X-ray pulse. The generation of X-ray flashes, especially with respect to efficiency and reproducibility, was achieved by W.P. Dyke and co-workers who were mainly concerned with field emission and its application for the production of X-ray pulse. These efforts eventually lead to the development of technically superior and commercially available flash X-ray devices which are now in use throughout the world for mainfold purposes. In scientific technological field, the flash X-ray radiography has long been known as an useful radiation source for the investigation of high speed phenomena and has been widely applied. The first part of this paper mainly introduces the work about flash X-ray radiography in China. That includes: flash X-ray radiography system, portable pulsed X-ray system and powerful pulsed X-ray sources. These equipments have been widely used in the fields of ballistics, detonation and biomedical studies. In the 2nd part, it mainly, describes the developments about flash X-ray radiography in the part of the world which includes: flash radiographic biomedical studies, X-ray pulse generators of high repetition rate, tomograpy and other applications.

The paper describes a new and novel video system which combines real time operation at 378 TV line resolution with the ability to capture, on command, a single high resolution 850 TV line image. The camera system incorporates a high resolution image tube giving shuttering periods as short as 200ns. The resulting photographic quality images may be dumped from the digital frame store to a hard copier or transferred to a PC for image enhancement.

Flash x-ray radiography with single pulse has been developed about fourty years. It is widely used to study instantaneous phenomena. Comparatively speaking, the flash x-ray cineradiography is a kind of advanced techniques. Especially the flash x-ray cineradiography using a single flash x-ray tube and generator is now in the ascendant. In this articale, the recent progress including principle, construction and application of the flash x-ray cineradiography at home and abroad, especially with single x-ray tube and generator has been described. It contains four sections: (1) Introduction; (2) Choice of the storage capacitor; (3) Charging and quenching; (4) Conclusion

The use of metal-halide lamps, with 4 times as much light output in comparison to conventional tungsten halogen lamps, has rapidly grown for high-speed-film use. Lamps range from 200 to 12 000 W. The color temperature will match perfectly with the requirements of daylight film. In combination with various high specialized optical luminaries and systems, the lamp shows outstanding performance and allows new applications. As the metal halide lamp is an AC-discharge type, a special power supply is necessary to overcome the the flicker effect. Electronic power supplies (EPS) with a square wave current characteristic allow flicker free films up to min. 8000 frames per second. Meanwhile the 3rd generation of EPS's will be introduced, which perform with even increased electric stability, compact size and decreased weight. This paper contains the practical uses in the field and possible future applications. Finally it gives a preview on future design and technologies.

A new photographic technique to measure the velocity of small particles flying at high speed has been developed. A pulse Ruby laser and an optical fiber system are employed for taking a double exposed photograph in a very short time interval. The delay time is precisely determined by setting the fiber length, then the accuracy of velocity measurements is mainly influenced by the measurements of moving distances of particles. This new technique is applied to observation of diesel fuel spray, and the usefulness of the technique is confirmed.

The methods and the resits of the measurements of the temporal and spatial resolutions of our X-ray streak camera are described. The temporal resolution measurement was performed by the method of laser produced plasma. Multilayer filters were used to remove the softer and longer X-ray pulses. X-ray pulse down to 33 ps in duration has been measured. An ARR CPM Nd:YAG oscillator was used to get even shorter laser pulses and preliminary result was obtained. The spatial resolution was measured by using grid form photocathode. The static spatial resolution of our camera up to 20 1p/mm and dynamic spatial resolution of 8 1p/mm have been realized.

We designed and tested a versatile strobe. Its principal parameters are summarized as follows: flash frequency, 0-10000 pps; discharge energy is adjustable in 0.1-1000 J range; flash pulse width, submicrosecond-milisecond; flash waveform, sharp or square wave. In this report, we described the principle of flash strobe and the choice of several main parameters.

A. "The ballistic-range of the flight line" is important current installation facilities for aerodynamic and ballistics in many countries. There are a tens of flash orthographical shadow photograph points which are the main test equipments in the ballistic range of the flight line. The tests shows, there can be 3 us unsychroniged intervels between the two-flashes at same photographical point. It could result in unnegligible measurement error. therefor. the synchronism of orthographical photography should be improved. B. One flash light source was divided as two orthographic flash lightsources by the "Y" optical fiber bundle with optical coupled devices. On this way, it not only has kept flash light synchronism strictly, but also simplified the optical structure-decreased in number of flash light sources. and improved the quality of photographes. The preliminary tests with the pockets showed that the optical fiber synchronization technic got satisfactory results. C. It is important to pay attention on the light transfer efficieney, the characteristics of point light sources and its symmetry, so that, the flash shadow photography is ever satisfified with light splitting sources, the spectrophotometric characteristics of flare light sources transmission rates of optical fibers for different band. numerical aperture. size and structure of optical devices size and place of the light source image. the terminal section size:and arrangement of fiber optical branches ect. All of those are important considering factors for designing optical coupled devices, fiber optical branches and choosing optical fiber materials.

This paper presents a new type of nondestructive detecting apparatus --- a serial pulse laser instantaneous holography instrument. Its fundamental principle, features, performance and its applications in engineering are described here. 1. Introduction; 2. Principle; 3. Applications;

After an introduction to the HOEs (holographic optical elements) and their unique features, this paper deals with their most promising applications in the military field, i.e., holographic laser safety glasses, holographic head-up displays, holographic helmet mounted displays. Finally, the holographic night vision goggles of the Belgian company OIP-OLDELFT are detailed.

Recently a new class of phase-shifting interferometers have been developed that allow us to measure optical phases with high temporal variations. A stationary diffraction grating plays the key role to split the input beam into 0, +1, and -1 orders and simultaneously to introduce a phase shift among the multiplexed beams. This simultaneous phase shift provides the capability for instantaneous measurement of optical wavefronts by using pulsed-lasers. The theoretical basis for the phase shifting interferometry will be introduced briefly. Also results of laboratory measurements will be shown for examples such as the wavefront quality of a pico-second pulsed-laser beam, surface figure measurement of an actuated deformable mirror, and the air turbulence induced by high pressure air flow at different temperatures and flow speeds.

This paper presents a technique of high speed interferometric photography for measuring time and space feature of transient flow field, that is single-path and multi-path high speed interferometric photography for transient flow field,and it discusses the principle of interferometric tomography and the method of time-serial high speed interferometric photography. By using this method and principle,the time-serial interferograms of shock wave in forming process from real rocket engine can be obtained, and three-dimensional temperature distribution about asymmetric flame can be calculated quantitatively.

The shock tubes are well recognized as simple but most useful experimental tools for modern aerodynamic studies l, 2. However, it may be their weakness that in general their working duration is too short to conduct the quantitative data acquisition. In order to overcome this difficulty the most easiest way of shock tube measurements will be the optical flow visualization. The traditional flow visualization techniques such as schlieren method or shadowgraph have limitation in evaluating the quantitative data from the photographs. Although the Mach-Zehnder interferometry can store the quantitative information of the flow field, it is too sensive to the quality of the optical elements and also to the homogeneity of the medium to be observed. For instance, in the Mach-Zehnder interferometry plastic glasses have never been used as observation windows nor underwater shock waves have ever been observed quantitatively.

This paper describes a basic principle of high-speed real-time holographic interferometry and its application technology in dynamic non-destructive testing, and introduces high speed holographic equipment and its research results of application experiment in various fields.

The microparticle field of products on detonation front was measured by the holography technique described in this paper. The results show that the velocity of product microparticles is about 5000 m/s. microparticle velocity permitted by holography and other related parameters are again calculated. The features and applicable extent for in-line and off-axis holography and the way using the space filtering technique to get a high resolution hologram image are discussed.

This paper introduces a kind of high speed holographic camera with many uses. Its laser output energy exceeds 1 J. The numer of pulse is adjustable from 1 to 26. The pulse width is from 3Ons to 5Ons and the coherent length not shorter than 2m. Under non-darkroom condition, this kind of camera can be used to do holographic interferometry for transparent and opaque objects. If it is colbined to use with high speed camera, high speed real-time holography can also be done. The main parts of the camera are also described respectively in this paper: the sequence pulse laser, the optical systeh and the electrical control system. The experimental results are given too.

We have raised, a new method, of asking lenticular plate by holography and embossing technology. This method is based upon the theory, of three beams of coherent light interfering, and it includes two steps: first, record an amplitude hologram of three beams of coherent light, second, replicate the pattern on positive photoresist films by contacting exposure. The lenticular plate obtained by this method consists of honeycomb closely packed, parabolic-shaped microlens. It is expected that its performance and aberration could be improved than that of spherical-shaped or columnar-shaped lenticular plate.

Model JSG-1 laser velocity interferometer is introduced in this paper. The instrument design is based on the VISAR principle and employes some recent developed teckniques. Some improvements have also made in our device. It has some features: compactness in construction, simplicity for operation and reliability in behavior. As a versatile system with wide measuring range and dual sensitivity, it can be widely used in shock wave and ballistics research.

The paper proposes a new peckle shearing interferometry using a rectangular grating as a shearing component, it has an advantage of an adjustable sensitivity after measurement, and remains the advantage of shearing interferometry using a sinusoidal grating. The rectangular grating diffracts the light in many order, the light interference among these orders produce the differential shearing patterns. Because the shearing amount of this method is changed with the diffraction order and diffraction angle, the sensitivity of the interference fringe pattern can be adjustable. The paper gives the practical parameters. To verify the method, we take the photos of loading cantiliver beam.

It has been found that, if a dispersion-free primary wave packet being identical with a material particle in the four-dimensional space is introduced, then the Fourier central component of the primary wave packet has a factor which is the de Broglie wave function. Thus it is infered that the electromagnetic wave is related to the Fourier central component of the photon as a primary wave packet. A light pulse like the Schrodinger wave packet is a secondary wave packet which may be even infinitely short in time, even infinitely small in space and may contain even infinitely small average number of photons.

This paper describes the performances of a passively mode locked ring dye laser which has seven mirror and four prism arrangement for group velocity dispersion compensation. It also discusses the second harmonic intensity and interferometric autocorrelation techniques. The shortest pulses of 19 femtosecond have been generated directly from this laser. Finally, we will introduce the method of the evaluation of synchronscan streak tube performances, using these short and stable pulses generated directly from this laser.

We have made a third generation of laser satellite ranging system in China which has been operated for three years. The light source is a high power ultra-short pulse solid-state laser. This ranging system has an accuracy about 5 cm.

The mechanism of intensity dependent recorded pulse broadening in the magnetic focusing femtosecond streak tube has been analyzed. The results have shown that it is due to broadening of an electron packet along the tube axis induced by space charge effects between the photocathode and the deflection electrode. Based on these analyses, a new tube with high dynamic range has been proposed. Photoelectron beam is swept by the deflection electrode immediately after it has been emitted from the photocathode. After passing the deflection electrode, the beam is focused by the focusing electron lens on the output screen. The temporal resolution of the tube is -500fs. Improved results are being obtained.

The mechanism of incident light intensity dependent output pulse broadening effect in the femtosecond streak tube has been investigated experimentally. In the experiment, several conditions were varied as a parameter to measure intensity dependent output pulse broadening characteristics. As the result, it has been clarified that broadening of the electron packet along the tube axis corresponding to high intensity light is not caused by space charge effects at a specific point such as in/close to the photocathode but is caused by accumulation of space charge effects induced between the photocathode and the deflection electrode, and that the broadening is temporally resolved and causes output pulse broadening on the screen. And it has been indicated that to shorten the transit time of electrons from the photocathode to the deflection electrode is a point to decrease output pulse broadening on the screen, and to extend the upper limit of the dynamic-range.

Two-wavelength laser ranging experiments with subpicosecond temporal resolution are described. To provide these experiments a reliable passively mode-locked Nd:YAP laser with two saturable dyes in the same laser cavity was specially designed. For laser pulses recording the commercial anglo-soviet Imacon 500 streak camera fitted with the PV-00l tube and matched with SIT-vidicon and computer data handling system were employed. The possibilities for further increasing of resolution and other recording characteristics of the developed installation are briefly discussed.

This paper reports a high stable CPM ring dye laser with chirp compensated by Multilayer dielectric mirror dispersion. The pulses generated by this laser are as short as 45 fs.

Waveform measurement of ultrafast optical signals is discussed as a promising application field of the streak camera technology. The key techniques for such measurement are elliptical scan and electron sampling. The optical oscilloscopes, which we have recently developed to perform the measurement mentioned above, are discussed on its operation and results of practical measurement. The results have showed excellent performances such as the time resolution of = 10 ps, the wide dynamic range of > 1:10 3, and distortionless, which features are far exceeding the limits of measurement by ordinary technique.

A new type of synchroscan streak image tube has been designed and manufactured according to its special applications to diagnosing ultrafast weak luminescent phenomena in our laboratory. It has presented high temporal and spatial resolutions, ultrahigh sensitivity of deflection, low RF dissipation and low background. A specially developed conductive substrate with surface resistivity of less than 10 Ohms/ and transmission of 80% has been utilized in this tube, which has eliminated the More effect and can be competible with the S-20 photocathode. Its static spatial resolution is better than 50 1p/mm and temporal resolution of 1.1ps has been achieved experimentally with RF deflection power of 9W and repetition rate of 200MHz.

On the basis of thoroughly theoretical analysis of physical processes inside the femtosecond streak image tube, we have developed a new streak image tube with temporal resolution of about 100fs. In order to reduce the initial energy spread of photoelectrons therefore to improve the temporal resolution and variance of temporal resolution and to refine the time response of the photocathode, a special thin photocathode with work function of 2ev has been introduced. In this tube an axial symmetrical electrostatic focusing system with short photocathode-to-anode distance and relative low anode voltage has been used. By optimization of its structure and voltages applied to its electrodes, its temporal dispersion depends only on the electric field near the photocathode which has reached up to 5-10kV/mm. By this design the space charge effects have been alleviated. To reduce the effect of fringe field of the deflector on the temporal dispersion and dynamic spatial resolution, to improve the sensitivity of deflection and band width a symmetrical meander type travelling wave deflector has been designed with the aid of computer and successfully used. The experimental results have shown that its sensitivity of deflection and band width are 10am/kV and better than 2.5GHz respectively. During manufacturing this tube a very efficient phosphor screen has been utilized therefore the dynamic current density of this tube can be reduced and the discrete space charge effects can be further improved. The temporal resolution of this tube obtained by the experiment under current conditions have reached better than 300fs which is in agreement with the data predicted by calculation with computer.

Two optical methods, used for diesel engine combustion analysis under realistic conditions are presented, the relatively new technique, namely endoscopic high speed photography and flame pyrometry. Their basic feature is optical access to the combustion chamber achieved through small sized windows (dia. 10 mm), fitted into the cylinder head of the engine. The outcoming image from the endoscope is transmitted to the camera through several rigid optical relay systems, interconnected with rotating optical joints. A flash bulb located behind a second window is used to illuminate the nonluminious process of fuel spray formation during the ignition delay period.

High speed Stereophotography may obtain 3-D information of the motion object. This paper deals with a high speed stereophotographic survey of dropping bomb in wind tunnel and measurement of its displacement, velocity, acceleration, angle of attack and yaw angle. Two high speed cinecameras are used, the two optical axes of the cameras are perpendicular to each other and in a plane being vertical to the plumb line. The optical axis of a camera (front camera) is parallel with the aircraft body, and the another (side camera) is perpendicular. Before taking the object and image distance of the two cameras must be measured by photographic method. The photographic rate is 304 fps.

The process of growth and collapse of spark-generated cavitation bubbles in clear water and sediment-laden water flow were photoed by high-speed framing photomacrography. Some important phenomena of cavitation were recorded. The paper describes optic multiplying system, high-intensity flash lamps, some analog experimental apparatus, synchronizing and automatic control technique used for high-speed framing photomacrography. Several theoretical analysis and calculation dealing with effect of viscosity, quantity of sediment inclusion in water flow and nearby boundary face on growth and collapse of bubbles as well as formation process of microjet were made in this paper. All the results provide experiment and theoretical foundation for further investigation of mechnism of cavitation.

Electrohydraulic technique is a kind of electric discharge by which the electric energy is transferred to the energies of heat, light, force, sound and other forms. This technique has been utilized in many fields due to its series of unique advantages. There is a great theoretical and practical significance in making a study of this technique. The Model ZFK-500 High Speed Camera was used to observe fair successfully the breakdown and the plasma-like state in the arc's path, the shock wave generation and propagation as electrohydraulic process takes place. A great number of photographs record clearly the leader of weak light during the breakdown and the whole electrical discharge process and the behavior while the plasma in the arc's path expands. Besides, the non-luminous phenomenon -- how a shock wave is created and spreaded out -- is recorded. These records provide a valuable scientific basis for doing research on electrohydraulic theory.

The high-speed camera can operate at framig rate of tens of thousands frames per second. The most serious problems are (1). the light source has not sufficient energy, (2). difficult to synchronize. Especially for photographing tne exploding process in which the dangerous area is relatively large, the ]ight source and the camera can not be very close to the photographed target. To obtain satisfactory effects, the source energy is required to increase by hundred times. The synchronization will be more diffi-cult.

We have developed a spark-gap system which permits a Cranz-Schardin type camera to be used for the recording of high speed events. A Cranz-Schardin camera is a high speed photographic facility which consists of a multiple spark generator used as a short-duration light source, an optical system which gives multiple shadowgraphs of the object on a still photographic plate, and an electronic control unit which provides delays before and between successive frames. In applying the Cranz-Schardin method to recording light emitting high speed phenomena, a principal problem has been the lack of reliable intense light sources with very short radiating times and restricted radiating areas. At the same time it is desirable to increase the illumination power as far as possible.

By making comparison between a few types of light sources, a removable and adjustable xenon light source had been successfully trial-produced to take clear photos of welding arc, metal transfer and molten pools. In the procession of investigating the technology of reflective high-speed photography, some problems for taking photos of welding arc, solidification of molten metal, especially the molten pools have been solved. This method has put into use in some research subjects and practical applications, such as "Welding Mechanism Research with Quartz-backing". "Comparison of Electrode Properties for Vertical-downwards Welding", and "Welder's Pressure Vessel-Welding Operating Demonstration", etc. the results were satisfactory and were praised by the profession of welding in China.

A new system of microcomputer-controlled stroboscope high speed photography has been developed recently. It has strong "frozen" ability, high photographic frequency, high accuracy of control time. Rapid-changing freqency of taking pictures and rapid-changing flash color are the most outstanding characters of this system. The Main technical parameters of this system, such as duration time of flashes, interflash time between flash and flash, flash numbers on one frame film and interframe time are controlled automatically by microcomputer. The synchronized operating of camera with stroboscope is also controlled by microcomputer. This system has been applied in multi-phase flow measurement and in physical training research. The results are successful and satisfactory. Usually, one flash is used to obtain clean "frozen" image, two-flashes can be used to get velocity data of moving object, and multiple-flashes is employed to gain the acceleration, track of moving object. While using multiple-times, multiple-color flashes, the moving tracks, velocity and acceleration vectors can be obtained.

A prismatic compensation high speed camera (mounted on a drilling test stand) has been used to get a continuous record of the whole working progress for a diamond bit or cutter brittle in organic optical glass, plexiglass,marble and other materials. Through analyses of these photographic data of drilling in brittle and plastic materials, a new understanding of rock fragmentation by drilling is acquried.

The necessary object brightness is proved to be proportional to the first power of the desired spatial resolution (in 1p/mm), or magnification, or target velocity in high speed photomicrography if the optical system parameters are chosen reasonablly. Experiment is described in which the dynamic deformation, wrest and shearing processes of metal crystal boundaries in the cutting area of a metallographically processed sample have been visualized.

This paper deals mainly the use of high speed photography technique, aided with identification, on the field of mechanism design. As an example, an experimental combined with mechanism synthsis has been taken on model JGN 202 wool loom for analysing the real movements of this mechanism. The lobby mechanism is of complicate cams and multi-linkages. Based on theoretical analysis and calculation, the displacement, velocity and acceleration curves were obtained for this mechanism by using of high speed photography technique. In comparison of the experimental results with the theoretical calculated curves, they appeared so closely. Not only the reliability of theoretical analysis can be checked properly, but also by the valuable data of errors presented between two sets of curves, experimental and theoretical respectively, further studying can be carried out about the affection of elastic deformation and clearence of this mechanism. Furthermore, the obtained data are reliable and accurate as the measurements were taken in non-contact condition, so it is an effective way to use this method for design and research of mechanisms evidently. Therefore, the introduce of high speed photography technique is of general significance in the area of researching work on mechanisms, and looking forward further progress appear far and wide.

The Fabry-Perot (F-P) velocimeter is a useful instrument for measuring the velocity of objects at speeds ranging from fractions of a kilometer per second to a few tens of kilometers per second and up. Because of its immunity to electromagnetic interference and its velocity resolution, it has become the prime diagnostic tool in our electric-gun facility. Examples of its application to high-speed experiments include the following areas: Electric-gun flyer studies; Spallation of materials under high-speed impact; Momentum-transfer studies; Pressure pulse created by high-velocity impact; Detonation-wave studies in high-explosive experiments. The F-P velocimeter at Lawrence Livermore National Laboratory (LLNL) includes a long-pulse laser amplifier, two-channel recording capability, air or fiber-optic transport of laser light, light enhancement through the F-P proper, and an electronic streaking camera with a microchannel-plate intensifier. Data reduction includes a digitizing system that employs a video camera and a personal computer for manipulating fringe curves and calculating velocities. Software corrects distortions from the streak camera used to generate the record. Our system yields a velocity measurement with an accuracy of 1 to 2%.

The theory of using high-speed real-time holographic interferometry to measure quantitatively 3-D thermal field is discussed in thispaper. An experimental arrangement, and the holographic interference fringes of thermal field formed by the electrAc heating coil wires which were taken by the high-speed camera are given. With CONCEPT 32/2725 computer system and corresponding programms the distribution of 3-D thermal field is calculated and plotted Finally, the problems required to be improved and solved for the method of measuring quantitatively 3-D thermal field are discussed.

We describe a holographic system that measures the size distribution of particles ejected from a shocked lead surface at speeds up to 2.8 mm/µs. Observed diameters range from 3μm to 50 μm. The three-dimensional distribution of the particles permits inferences about the uniformity of their distribution and velocity. Comparison of the holographic results for the mass with those obtained using a momentum transfer technique show general agreement but indicate that further refinement of both techniques may be necessary.

The different kinds of projection type moire topography were compared briefly in this paper. The improved method of preparation and arrangement of gratings were introduced, and the real-time moire equidifference line method was proposed in principle. In addition, the approximate formula of equidifference line in non-telecentric optical path, and the principle and method of reproducing the reference grating were given. Finally, by means of the combination of projection type moire topography and real-time moire method with high-speed photography, the vibration of a thin beam fixedly supported at two ends and the impact deformation of a cantilever beam were recorded. The results of the qualitative analysis and patial quantitative analysis for them have been given.

The sensitivity of the dynamic white light speckle method is analysed by the concept of the frequency spectrum analysis of the incoherent imaging system and the method of increasing its sensitivity is presented in this paper, If a photoelastic material is taken as the specimen, the dynamic isochromate patterns are obtained under the same load at the same time Therefore the stress and strain of the structure are solved,

The advent of effective solid-state pulse lasers operating in the 3-pm range [1, 2] that became available during the last ten years sets forth the problem of designing methods of registration and visualization of laser radiation within this range. Today, a researcher may choose from a good number of IR radiation visualization techniques resting upon the effect of a change of properties in various materials under the influence of heat [3]. In terms of such indicators as sensitivity, dynamic range, resolution, as well as a number of operational characteristics, the "thermal sensitization" technique applied to silver-halide photoemulsions [4] is far superior to any other available technique for visualization of IR radiation pulsed laser fields. This technique has been originally applied to photoregistration of pulsed gas laser radiation in the range of 5 and 10 pm. This paper presents the results of the experimental study of the potential of the method for registration of a YAG:Er3+ laser radiation at λ = 2.94 μm. The following parameters were determined: sensitivity, 2 mJ/cm2; dynamic range, 100; resolution with the generation pulse duration of 200 μs, not worse than 50 lines/mm.

This paper describes briefly the study task conducted in high-speed holography and its recent development situation in our institute. Holographic high-speed interferometry and optical image processing are main directions of the optical lab. in our institute. Recently, we have done some research on holographic interferometry method. Holographic technique, optical image processing (including coherent and incoherent and optical digital hybrid image processing) and relative equipments design and developing. Some outstanding results have been got. Now, as far some main respects we give a brief introduction.

Techniques are presented for obtaining time-resolved sequences of holograms and holographic interferograms of a shock wave impinging on a model in a shock tube. Several images are multiplexed on a single frame of film using a stationary, focused object beam and an angularly swept reference beam. At the reconstruction stage, the direction from which the reconstruction beam is shone determines which image is observed. In the original implementation, angular sweeping of the reference beam was achieved by the combination of a flat spinning mirror with a circular mirror that redirected the light on a fixed area of film. The holographic light source was a ruby laser, multiply Q-switched by a Pockels cell at rates of up to 20 thousand pulses a second. The method has been used to record either schlieren images or holographic interferograms of shock waves. Schlieren images of the phenomenon were holographically recorded by introducing an aperture at a focal point in the optical path of the object beam. Holographic interferograms were generated by overlaying two sequences on the same medium, one containing the phenomenon and the other the undisturbed field (reference exposure). The spinning mirror equipment is capable of recording sequences of some 10 frames at 50 μs separation, over a useful sweep angle of about 110°. Proper timing of the sweep with respect to shock arrival was not assured with the original spinning mirror design, and there were additional problems with registration between successive sweeps and with "time smear" of the holographic recording. A solid state design based on ferroelectric liquid crystal electro-optical shutters is currently under development. In addition to eliminating problems with synchronization, registration and smearing, such a system would be uniquely suited to simultaneously recording the reference exposure on all frames.

The performance of a framing holography system using a pulse laser is discussed, and two kinds of new methods are proposed. As a holography system has no lens, recorded images using the system are free of image-distortion due to the lens aberration and the out-of focus due to the finitness of depth of focus. Many kinds of lasers are used for the light source of holography. Especially GP ruby laser is usefull for the holography recording of high-speed phenomena. Two basic methods of recording images using the framing holography system are shown below. The first is, the each pulse generated from multiple laser resonators is divided into two parts. A part of them illuminates the hologram from different directions as reference beams, and the others are tied up into a beam to illuminate the object as an object beam. The second is, a pulse train is generated from a single laser resonator and divided into two parts, a half of them continuously illuminates the object as an object beam, the others are used as reference beams of which the incident angles are changed with pulses by electro-optical devices. With this method, each image on a hologram holds its independency and can be reconstructed independently, The first method is favorable, especially in the case that the number of recorded images is 2 or 4. A two-frame recording system is constructed as an example of the first method, and sufficient performance is attained.

The propagation of detonation in solid, heterogeneous high-explosive charges is an outstanding problem of detonation physics and much effort is made in numerical modelling of special effects belonging to this topic. Demonstration of strengths and weaknesses of new numerical methods however need comparison with experimental data received from special high-explosive tests.

An x-ray streak camera with a time resolution of ~30 ps is described. CsI and Au were used as the photocathode with Parylene substrate for the camera, making the camera sensitive to x-rays from 100 to 10,000 eV photon energy range. The transmission of the substrate and the quantum efficiencies of the photocathodes have been measured. X-ray pulse down to 33 ps half width has been measured with 8 1p/mm dynamic spatial resolution, 12 mm slit length on photocathode and ~32 dynamic range. The jitter of the avalanche transistor sweep circuit is smaller than ±150 ps. Some primary results of laser fusion studies have been obtained with this camera and pinhole imaging system.

A new method of x-ray picosecond framing photography was proposed to obtain four frame images. This method uses a double-pinholes x-ray imaging system and an image tube with a deflection shutter system which consists of a pair of shutter plates, two pair of separating plates,double-slits aperture and a pair of compensating plates. A ramp voltage is applied on the shutter and compensating plates. The framing tube with internal MCP intensifier was manufactured. Static resolution of 20 1p/mm was identified using an X-ray source. The obtained four frame quasi-static images with repetitive exposure showed the reality of the new framing concept. The dynamic characteristics of the camera were measured with X-ray emission from laser plasma. Four frame images have been obtained with "170 ps exposure time for each image and "3 1p/mm spatial resolution.

In this paper, a system for measuring picosecond time-resolved spectra of low-light-level fluorescence is described in detail. The system consists of an active mode-locked Ar+ laser, a sample cell system, a monochromator and a non-synchronous scanning streak camera system. The results of the measurement are given for typical samples with time resolution of 10 ps and wavelength range of 500nm-800nm. Finally, the measurement results are analysed and discussed.

Present-day experimental physics and laser technology set forth increasingly high requirements to fast process parameters measuring means. Some 10 or 15 years ago, investigations were focused on processes of a nanose-cond duration (10-9 s), whereas today research demand measurements in pico (10-12) and femtosecond (10-15s) time ranges.

The design and measured performance of new femtosecond streak camera are discussed. The experimental setup that has been employed in the assessment of the single-shot streak performance of the camera will be described and data will be presented to show that the present design of camera has a resolution of approximately 300fs. This is very close to its theoretically predicted temporal resolution of 250 fs for current operating conditions. Design modifications aimed to further improve camera performance to its limiting temporal resolution of ~100fs will also be outlined.

An oil film detonation experiment was conducted in a rectangular shock tube with a thin layer of n-octanol coated on the bottom wall of the tube as a nonvolatile fuel and with gaseous oxygen in the tube as the oxidizer. The film detonation was initiated by a shock wave generated by the gas phase detonation of a H2 - 02 mixture in the driver chamber separated from the main shock tube by a thin mylar sheet. Piezoelectric pressure transducers were employed for the detection. The propagation velocities and the pressure ratio of detonation wave to the driving shock wave were determined from the recordings of the transducer outputs. The wave structure and the propagation process of the film detonation were investigated by means of high speed schlieren photography with a framing rate of 2x105fps.

The high-speed photographing technology is used to analyse the atomizing process of RE-Si ferroalloy. The mechanism of atomizing droplets is discussed; the theory of dividing the atomizing process into five zones is put forword; the reliable data for designing the construction of atomizing device are provided.

An experimental system that consists of rotating-prism cinecamera with macro-zoom lens and optics for photography of oscillo images, and piezoelectric dynamometer, digital storge oscilloscope was used for recording the chip formation process and the instantaneous fluctuation of cutting force synchronously in machining titanium alloy. A process model of the serrated chip formation has been offered. Studies on chip formation process lead the authors to conclude that the localized concentration shear caused by adiabatic cutting process plays an important role in titanium alloy chip segmentation.

Two digital devices were developed to enhance the possibilities of high speed thermo-visers in thermal nondestructive testing : digital thermograms processor with a memory DTPM-1,2 and microprocessor unit MPT-1.These units could be used either in a single variant or together with a personal computer to increase the reliability of inner defects detection in solids against the specific noise. Princinles of thermal tomography are discussed.

The paper suggests experimental results obtained in application of the tomographic techniques to high speed frame recording.

At the 13th Congress in Tokyo, I presented a paper with this title in which some early history was mentioned followed by a more detailed study of the activities of the main research groups in Britain from the period between 1950 and 1978. On this occasion, some early topics will be mentioned. The period since 1978 has seen quite a few changes in that research is now more in the hands of commercial groups as opposed to the previous governmental laboratories. It is true that the pricipal camera systems have reached towards their physical limits. However other new techniques are still expanding, for example, Lasers, Holography and Videography. The new systems are principally in the hands of major or specialist companies with the offical and industrial research groups using their products. The Association for High Speed Photography continues to encourage both researchers and users by providing oportunities for users, suppliers and manufacturers to meet and discuss.

We show and demonstrate a new concept of a Bistable Optically controlled Semiconductor Switch : BOSS. The switch can be turned on and off with light pulses of different wavelengths in a nanosecond time scale. The calculations promise high current ( MA )and high voltage ( '100kV ) feasibilities. We use a control mechanism of the whole bulk material at the same time. We discuss semiconductor and impurity materials for this new device.

A ballistic gas simulator that permits the generation of relatively clean, two-phase, reacting flows with realistic gas pressures and temperatures has been developed. This device is driven by the combustion of light gas mixtures such as hydrogen mixed with oxygen and helium. The experiments performed were aimed at the generation of well-defined, well-controlled flows beginning with reacting single-phase gas flows. The main gas parameters to be measured are pressure, temperature, and gas velocity. A novel intrusive temperature gage technique and other spectroscopic techniques were tested in two-phase flows to obtain information on the gas phase temperature. In addition, a Michelson-type laser Doppler velocimeter, devised by Smeets at the Franco-German Research Institute (ISL), was adapted so that gas velocity data could be recorded continuously with a time resolution of about 10

The measurement of axial motion of the projectile along the gun barrel against time is one of the important methods to study the work-doing ability of propellant powders. The interaction between gun bore and projectile is interesting to many ballistician and designers. The velocity of the projectile changes from zero to several thousand meters per second, so it is difficult to observe the velocity history because of its highly non-linear velocity history and short effective time interval. The whole course in barrel is of great interest. For designers, the shooting moment is the most interesting. The measurement of the data is the most difficult task, and therefore, the highest resolution of the instruments used is requised. Because of its high resolution, F-PVIS is the suitable equipment for measuring the projectile moving in the bore. The retroreflector used is the key element of success and must meet strict requirements. The CV' He-Ne laser beam is di-rected via a-4disposable mirror down the barrel onto the retroreflector glued to the projectile. The Dapple shift of wavelength of reflected beam is proportional to the projectile velocity. Then, the shifted beam passes through a F-P interferometer and is recorded with an image converter tube camera. The basic principles are discussed together with some typical results from the experiments on 30 mm smooth bore gun. It is important to seal powder gases and nylon driving band can be used.

The impact behaviour of a range of glass and ceramic materials has been studied using high-speed photography. A gas gun was used to project hardened steel spheres at plate specimens in the velocity range 30m s-1 to 1000m s-1. The target materials included soda-lime glass, boron carbide and various glass ceramics and aluminas. The controlled impacts were viewed at microsecond framing intervals using a Hadland Imacon camera. The camera was triggered by the projectile interrupting a laser beam. Results from these experiments have identified the various failure modes of the materials and given quantitative data on the energetics of impact. The performance of a particular ceramic was found to depend on a combination of parameters but of key importance was the relative hardnesses of the projectile and target materials. Targets which were harder than the projectile (for example, alumina or boron carbide targets) deformed and fractured the projectiles and prevented penetration. However, targets which were softer than the projectile (for example, glasses and glass ceramics) were penetrated relatively easily. In both cases, the fracture toughness, KIc, had only a minor effect. The results emphasize the value of high-speed photography for studies of the complex phenomena involved.

When a heavy-calibre gun is fired and a projectite is flying near the gun muzzle, velocity of the projectile is very high and firing process is accompanying with strong muzzle flash. So taking the picture of the attitudes of flying projectile at the gun muzzle is very difficult. "YDS speed Photography System" developed by our group can take the framing pictures of the attitudes of the projectile and prevent them from flash confusing at the muzzle. Since framing depends on sequential pulse of the laser and the width of the putse is very narrow, therefore the exposure time is very short and photos of high-velocity flying body taken are very clear. This paper Introduces configuration and operation principle of "YDS laser High-speed Photography System" and the fuctions of the devices in this system In addition, some experimental results are briefly introduced.

The paper presents some results of investigations of head shock wave and shock layer instability in front of blunt bodies and wake disturbances behind these bodies in polyatomic gases. The experiments have been carried out on a ballistic facility using the high-speed pulse photography systems. The obtained experimental data indicate that shock wave (SW) instability and flow disturbances are caused by anomalous relaxation (AR) phenomenon.

The new results of laser ballistic array photographic technique are presented in this paper. The characteristics of shadow, schlieren and front light photography with laser used in ballistic array system and their applied ranges are discussed. The techniques of automatic synchronous trigger by microcomputer are given. The automatic synchronous triggers can be finished in the case, as the velocity of the flying projectiles to be measured is not pre-known accurately and there is the large deviation of the velocity of the projectiles in flight according to the flying law of the projectile after launching. A new mathematical model is advanced and the microcomputer programs are designed. The experiment results show that the method is a success. The correcting technique of velocity attenuation rules of flying projectiles in air for the array photography system of several photographic stations to take more photos in long distance is described. Finally a few conclusions of the technique of laser high speed photography used in ballistic array are given.

When a high-speed photograph is being taken, the re-exposure often occurs on the film exposed by the signals before. It may disturb to identify the signals, even spoil the experimental data. Using the technique (controlling exposure amount and cutting off the beam path) described in this paper can effectively prevent the film from re-exposure.

That the actual solid rocket motor behavior and delay time of the ignition of Ap/HTPB composite propellant ignited by high energy pyrotechics contained condensed particles have been investigated is the key of this paper. In experiments, using high speed camera, the pressure transducer, the photodiode and synchro circuit control system designed by us synchronistically observe and record all course and details of the ignition. And pressure signal, photodiode signal and high speed photography frame are corresponded one by one.

This paper presented a new method of measuring the velocity distribution of shaped charge jet according to flash x-ray pictures of the broken jet-Stretching and Breaking up Method, this method not only saves materials but also reduces experimental work considerably. Its results are in agreement with those from "Jet Truncating Method". Its accuracy can meet the needs of engineering purpose.

The multi-wave structure of the stress wave in an explosively loaded plate and the front width of stress wave profile are diagnosed with F-PVIS (Fabry-Perot Velocity Interfero-meter System) and ORVIS (Optically Recording Velocity Interferometer System). Under various explosive loading strengths, material free surface velocities of various thickness plate Ufs are measured. High resolution records obtained from this laser Dopple velocitymeter clearly show the velocities and amplitudes of elastic, first plastic (phase transition), and second plastic wave etc. Hugoniot elastic limit, phase transition point, and various loading strenth points are measured and the P-v Hugoniot are drawn in low pressure range. The leading shock and trailing rarefaction interact with the front free surface. The shock wave reflects from the free surface as a rarefaction wave propagating backward. When two opposing rarefaction waves collide, material on either sides of the interaction plane will be accelerated in opposite directions. This will result in tensile stress. If this tensile stress is great enough, incipient spallation will begin to occur at the interaction plane. Shock wave which is generated by spallation will propagate toward and reflect at the front free surface, and its reflection wave will propagate and reflect between two free surfaces repeatedly. That will cause the oscillation of the Ufs(t) curve. The amplitude Ufs is called pullback and can be used to compute the spall stfength. Some typical measurement results by using F-PVIS and ORVIS are discussed as well as the resolution of instruments.

The high-speed photography is an important instrument of researching tree phenomena of the high-speed object, especially for observation of many high-speed and instantaneous variation phenomena in weapon systems. The satisfactory results can be achieved from the instrument. This paper will introduce the new Model ZC-II Ballistic Test System employing ruby pulsed light as source. It will also give the performances of the design, its main parts and the method of photography by which the interesting pictures of the standard 7.62 mm Type 56 bullet both in flight and in target in different instantaneous postures have been achieved.

The study of deformation and broken mechanism of a solid medium loaded explosively has been paid attention to. It is more and more urgent that the mechanism of blasting and fracture be deeply studied in numerical quantities by new effective experimental methods and techniques. For this reason, the authors have made every effort to establish a new optical dynamic measuring system - superdynamic moire method measuring system (SDMM), which consists of the transmissive moire measuring system based on the multiple spark high speed camera and the reflective moire reasuring system based on the ultra high speed rotationay framing camera (GSJ type). A lot of experimental results proved that the system has good effectiveness and stable characters. First fruits have been reaped by using the SDT to study explosive mechanics and fracture mechanics.

This article introduces a method of photographing projectile flight velocity with a sort of framing photographic camera. This method is practically significant in non-contacting measuremert for determining projectile mean flight velocity on the basis of analyzing the round shooting phenomenon of lateral armor-piercing mine,it is necessary to record the phenonmenon of the initial and final conditions to fulfill the photographic plan by the high speed frame photographic camera. It has turned out a success, in addition, we analysed the precision accuracy of error for initial signal and raised an acceptable high soeed nhotogrerhic method under long range firing circumstances.

The direction of crack noncolinear propagation of composite material is observed by geometric moire' method. GFRP specimens with single edge notched are subjected to static and dynamic tension. Moire' patterns representing displacement component perpendicular to the reference gratings are taken. From these patterns, curves of strain distributions with polar coordinate are obtained. Directions of crack propagation obtained by moire' method are agree with practice.

This report describes mainly applications of ZDF-50 High Speed Camera developed by Xian Research Institute of Optic and Precision Mechainics in China in simulated long rod projectile penetrating various targets. The analysis of photographs has been carried out. In addition, the problem of how to utilize the pulse-power of Xenon Flash Lamp to protect camera from re-exposure is dissucused:

This paper discusses an application of high-speed photography method in measuring dnamic gun accuracies during the gun firing test. This method has solved the overproof problem of the burst firing density to the vertical screen which has existed in a small calibre rapid-firing gun for many years, and decreased in the elevating probable error by 59%. This makes the gun come up to the present advanced stage at home. Secondly, the paper describes briefly the dual scaling method used, the picture processing, and the method and measures improving data processing accuracy. Since the time scale is improved in the high-speed rotating prism camera, its functions are improved.

Several optical, single transient data imaging systems have been developed at the Lawrence Livermore National Laboratory for providing time-, space-, and intensity information of pulsed radiation sources. The basic components of these systems are fast-gated cameras, large-bandwidth transmission lines, large memories, and image processors. Gated MCPI are used with solid-state, one- or two-dimensional array cameras to record individual frames of an optical pulse. The MCP intensifiers are designed to provide large gain (> 10 6 electrons), fast optical shutter (≤1 nsec), low shading (≤10%), high spatial resolution (10 1p/mm at 50% CTF), and high sensitivity in the near UV (420 nm). Several methods are currently investigated to (1) produce faster optical gates without significant irising or reduction in resolution, and (2) to improve spatial resolution. Both photodiode arrays and charge-coupled devices (CCD) are used for the imagers in the solid-state cameras. These cameras are designed to achieve a large dynamic range (500:1), low saturation fluence (≤1.5 erg/cm2 at 420 nm), and small frame time (≤2.5 msec). Several commercially available imaging arrays containing 1035 x 1320, 512 x 512, 488 x 380, 128 x 128, 100 x 100 pixels each, with pixel diode sizes of ≤15μm, are examined for blooming, cross-talk, blemishes, and uniformity. Current investigations are concentrating on large segmented (512 x 512) photodiode arrays with CCD readout. All cameras are designed for fiber-optic or lens coupling. Maximum dynamic range and maximum signal-to-noise is achieved by using 8-, 10-, or 12-bit A/D converters. Large bandwidth fiber-optic transmission lines (720 Mbit/sec) and large memories are used for arrays with > 105 pixels, 10-bit A/D converters and short frame times. A technique known as data compression is applied to take advantage of a 10-bit system using an 8-bit data acquisition arrangement. The advent of large array cameras requires modifications in calibration procedure, data acquisition, and image processing. Gated optical imaging systems are used as a diagnostics on electron beams and plasma-, x-ray-, gamma-ray-, and neutron-sources too provide a snapshot of each event with high spatial resolution.

The idea of a new high speed CCD-camera which was presented on the 17th ICHSPP1 is now realized and the system is avalaible on the market. In the present paper we show first experiments which demonstrate the impressive picture quality. The high speed video camera uses a frame transfer sensor. The sensing and the storage area on the chip is divided in such a way, that we get a smaller sensing area and a larger storage area. Then it is possible to take more than one picture in the time of 40ms, which is the standard read out time of TV-sensors for a frame. At present the spatial resolution of a 576 pixel CCD is 420 lines horizontally, the number of lines of a frame is reduced to 576/n depending on the number n of pictures in a high speed sequence taken in 40ms. The high speed camera offers the possibilities to use periodic steps between the frames or nonperiodic. Moving of pictures on the sensor itself can be done very fast, at present the speed limit is 15Ons/line. The pictures of the high speed video camera show an expected high sensitivity, resolution and good separation of single frames in the high speed mode. The output signal of the camera has the normal video standard. This makes it possible to use inexpensive videorecorders to store the pictures and standard TV-monitors and video printers for display.

Solid state imaging devices are increasingly replacing conventional photographic techniques in many fields. This paper describes a high speed camera which makes use of two special features of the frame-transfer CCD imager, namely its simultaneous integration process over the whole sensing area and the subsequent shifting of the charge distribution into the storage register. Details of the system and its application in the investigation of disintegrating jets are given.

Most of the present high speed pickup cameras consist of a CCD pickup camera and an additional mechanical shutter or electronic shutter. It is well accepted to develop the CCD's own shutter function directly without an additional shutter. In this paper is presented a method to develop the CCD's own shutter function. It starts with shortening the "useful charge integrating" time of the pickup camera per field for the shortened field integrating pulse to act as the electronic shutter. At the same time, the "useless integrating charge" except the "useful integrating" time per field must be cleared by the method of "photographic plate clearing" to set the "useful integrating" charge on the clean photographic plate which has been cleared, thus accomplishing the transformation of an ordinary CCD pickup camera into a high speed camera with its own electronic shutter. After analysing the performance of the newly-developed high speed pickup camera, two examples of the application are given, especially when this pickup camera is used to take a picture of a body which spins at high speed, a clear, slowly spinning or even relatively still image can be obtained directly and it is unnecessary to shoot quickly and play slowly with the aid of a videorecorder.

Auto-tracing Synchronizer is a new multi-functional apparatus for timing and delay, it can measure and display time intervals in microsecond and according to be measured object it can output multi-route delayed signals in accuracy of 0.2 us. the apparatus solves synchronization problem in high-speed photography. It has strong ability in disturbance resistance and can be operated under crucial conditions with intense electro-magnetic disturbance, such as discharge voltage at 1 MV, discharge current at 10 KA, electro-magnetic field intensity at 5 KV/m. This paper presents the applications of the apparatus and some results in pulsed X-ray photography, visible-light high-speed photography and in dynamic Photo-elasticity.

Errors in measurement of photographic image are inavoidable. The important thing is how to reduce them to a certain extent which is acceptable. Therefore, it is necessary to analyse error source, to detect error values and to control error extent. The last two problems are briefly discussed in this paper.

The readout system integrated software for processing of images which could be the output of the picosecond streak camera has been proposed. The readout system on the basis of cooled CCD is using for the pulsed streak image acquisition. IBM PC XT/AT compatible personal computer perform readout control and image processing. The software includes readout system control, an image input, image processing, spreadsheet handling, graphics and text editor.

Two main elements which the dynamic accuracy on high speed photography are photographic system and analytical system. The performance of photographic system chiefly comprises the characteristics of camera, resolution of optical system and film, frame rate, photographic reduction and magnification, the characteristics of time mark, the characteristics of light source and method of illumination, etc. The accuracy of analytical system chiefly comprises the limits on precision of input data caused by the system itself, in principle, accidental errors caused by the person and environment at the time of analysis, propagating errors of function in the case of the indirect measurement and so on. The paper mainly describes the research of above problems theoretically and experimentally.

A real-time phase detection method is proposed for restoring three-dimensional profile from fringe patterns generated by deformed grating method or interferometry. The method uses the digital signal processing technique, DPLL(digital phase-locked loop), for extracting the phase distribution directly from the video signal of fringe image. This method is easy to apply to practical measurements and vision systems which need a fast information processing capability, because the phase distribution can be extracted in video-rate with high accuracy and it is suited to a computer base system. The principles and the experimental results are presented in this paper.

A main technical procedure of restoration of the images degraded by a high-speed photograph system is described in this paper. A new posterior model is presented. In the model degrading information is extracted from a set of degraded images, which result from a given sample, but not from observed image to be restored. The conventional linear filtering techniques can be employed to estimate the image which has been blurred by a nonlinear-space-variant system. The processing results obtained by the means are also provided.

A. simple, low-cost film analyzer, named KD-9 IMANA, was developed for high speed cine film interpreting and data processing. The X and Y coordinate values of interested image points are digitized using magnetic induction principle and transferred to a personal computer through the RS-232C standard interface. KD-9 IMANA is equipped with LAA measurement and MOTION analysis program having sixteen physical quantites as standard outputs and allows users to make their own programa of data processing with BASIC language. This unit can also be used as a graphic analysis device.

The general equations of direct linear transformation (DLT) are derived according to the actual process of high-speed stereophotogrammetry. The equations are not only applicable to the ordinary photographic system, but also to the photographic system with reflectors or stereo-reflectors. The equations are also suitable to the enlarged, copied and projected measurements of photographic film. The linear and non-linear errors in photogrammetric process can be corrected. Finally, the equations of right angle intersection photogrammetry are given and the merits and demerits of this method are discussed.

As for the temporal resolution of a scanning photography, its connotation and definition, its measuring method, and its assessing criterion could not be considered determinate and unitizing in high speed photography field. Those mentioned above, in this paper, have been discussed, and some suggestions to establish the assessing criterion of the temporal resolution have been presented.

An integrated design of a time mark generator with high precision, high stability and high frequency was suggested. Obtained from the quartz crystal oscillator through the dividing network system as a driving source, the use of the GaAsP solid luminescent diode as the pulse light source and the use of the signal have advantages over other methods (mechanical, neon light tubes, discharge sparking, etc.). These advantages are: Light in weight, smaller in size, better in anti-seismism and less driving power. Because the luminescence wavelength coincides well with wavelength peak of the film sensitivization curve, the time mark frequency is very high (to 100Khz/s) and more stable. This generator is designed especially for the slit mode high-speed camera, and it can also be used for other synchrocameras.

This paper describes an analysis system of high-speed photography film. This system has two modes. In the case of the semi-automatic analysis mode, a series of coordinates of the filmed particle can be get by using the cursor. Then the data are processed by the microcomputer and the velocity, acceleration and other movement parameters are printed. In the case of automatic analysis mode, the cursor is used to produce a gate signal which determines the range of digital image. The video signal in this range is given a realtime A/D conversion, then it is put into the image buffer. Microcomputer processes the digital image and gives the coordinate of the marking point, then just like the semiautomatic analysis mode, calculates the velocity, acceleration and other movement parameters.

The digital image processing for flow visualization pictures, including air-bubble, smoke tunnel, schlieren and interference are described. The ways for calculating data quantitatively also provided. In this paper the histogram equalization, spatial convolution, exponential transform and Wallis transform are introduced.

The high speed photography & photonics have been used widely in the field of mechanics in China such as the study of shock wave, exit trajectory, armor-penetration, shock tube wind tunnel, propagation of stress wave, crack expansion, mechanical properties of material under impulsive load, interaction of laser with target, exploding wire, biotrajectory, explosion welding, blasting engineering and other applications in industry. Some techniques such as the dynamic speckl, dynamic morie, X-ray photography, dynamic photoelasticity, high speed schlieren, high speed interferography, and stroboscopic light source etc. have been used. Several instruments of HSPP used in mechanical research such as the stroboscopic Ar laser source with frequency of 5kc, stroboscopic He-Ne laser source with frequency of 20kc, double mirror interferometer with aperture of 150mm in dia., synchrolized pulsed He-Ne laser, auto-following synchronizer, 1000kv pulsed X-ray generator and its con-troller for four sets and the multi-spark high apped camera have been researched and developed. The ordinary type of the rotating mirror, stand-by and prism compensation high speed cameras, schlieren and Strobokin are also used widely. Many application pictures are also presented in this paper.

The airblast precursor is a shock refraction effect formed by the interaction of a shock wave with a high-sound-speed layer. Helium was injected through a porous ceramic plate to create such a layer near the wall of a small shock tube. The flow was made visible by shadow, schlieren and interferometer photography. Incident shock Mach numbers of M = 1.7 were used. A prominent feature of the flow is an unstable supersonic wall jet that develops large-scale, turbulent structures.

This paper describes the principle of the color schlieren technique which uses a piece of square color filter for the source mask and a square hole for the cutoff mask. From the viewpoint of chromatics theory, this paper also describes the relatioship between the color of the element on the image and the deflection of the emitting light rays, and the formulus of the amount and the direction of deflection of the light rays are given. In addition, this paper describes in details the application of the technique to a test of transonics flow around a NACA 0012 aerofoil. The result compare with the surface pressure measurement by the sensor. Apart from the consistency between the two methods being used, the shock wave and the Mach lines shown directly in the present method can complement and revise the results taken by the pressure sensor.

The sequential pulsed, Q-switched ruby laser is used for the light source. Liodel 640 schilieren apparatus is used for the display optical system of image and flow field. The access type rotating mirror scanning high speed camera is used for recording unit. They are assembled into a complete set of Pulsed Laser High Speed Schlieren Photographic System. So far, we have designed and trial-manufactured two types. The Model I system is used for recording the armor-piercing process of the terminal trajectory and the chamber-shooting process of the midway trajectory. The better results have been obtained. The Eodel II system is used for studying the detonating mechanism of high energy dynamite. The framing pictures of the bullet flying attitude before bullet collides the target and the compressive deformation after it collides the target as well as the detonating process have been taken. These photos have provided the basis for research work. The future development of the system has also been discussed in this paper.

A large frame schlieren image technique is presented in the paper. The technique has been applied to visualization of the boundary layer transition on the surface of the cone in the hypersonic flow. The schlieren pictures obtained from wind tunnel test are processed and measured by a micro-densitometer and a digital image processor. In terms of the computation based on a schlieren theory, the relative density profiles at various cross-sections and the transition region in the boundary layer can be shown. The measured results are compared with theoretical and other experimental results. The freestream condition in the present experiment is as follows: Mach number M=10.29. Reynolds number per meter Re/L=1.38x 107(1/m) and density ρ∝ =3.14x10-5(g/cm3).

The housefly is equipped with an excellent visual guidance, flight control system which enables it to track small, fast moving objects in its visual field[1,2]. These mechanisms of visual orientation and guidance were investigated by means of an analysis of chasing flight induced by visual objects [3-8]. The acceleration of the chasing fly was investigated by analyzing the trajectories of its chasing flight in free flight conditions in a cage. In order to record the three-dimensional trajectories of the flies in the cage, a mirror was mounted beneath the bottom of the cage at 45 degree angle. A high speed cine camera was used and run at 200 frames per second.

This paper reports the effect of various different laser spot-sizes on both fine-structure of waveform and pulse duration while measuring pulse waveform of a large aperture high power solid laser with a streak camera.

The diverter is one of the most important parts of a liquid flow calibration system. However, if it is not properly designed and installed, significant errors can result. To evaluate the diverter system and quantify its performance characteristics, an experimental method by the use of high-speed photography is presented in this paper. Based on the experimental results, the accuracy of the calibration system, as well as the design of the diverter system can remarkably be improved.

An experimental method for visualizing the flow field within centrifugal pumps is presented in this paper. The working liquid used in experiments was a water-based multimolecular polymer solution in which polystyrol particles were added as the trace particles. A rotary-prism type high speed camera and a motion analyzer were applied to investigate the internal flow field of the pump on the line. The particle paths and velocity distribution in the flow field have successfully been obtained. It is naturally expected that this method can be used to give improvement in the design of centrifugal pumps, in which the separation and vortex intensity will be reduced, but efficiency raised.

This paper has utilized pulse laser microphotography to record the highspeed and dynamic atomization in the mixing chamber of EQH102 carburetor, used for Dong-Feng EQ6100 engine. Experimental methods has been investigated. Influence factors has been analysed, and some technical measures were adopted. finally, we have got the initial results.

The raster plate to be used in high speed photography is made of gradient index (GRIN) fibers. After analysis, the relationship between the size of image element and parameters of GRIN fibers selected is given. The paper introduces the techniques to fabricate the raster plate. The main problems should be solved are how to put the fibers in good order and how perfect optical identity of them can be achieved. Using the methods, the GRIN fibers raster plate have been made, small image elements and clear raster image points have been obtained. The typical parameters of the raster image plates are listed as following: 120 thousands lenslets are in an area 18 x 25 mm, the diameter of single lenslet d = 0.055mm, focus spot s = 3.5 um, numerical aperture N.A. = 0.3 and focus length f = 0.1mm for raster A; and 18 thousands in 60 x 60mm , d = 0.3mm, s = 3.5um, N.A.= 0.3, f = 0.41mm for raster B.

This paper describes development of versatile one-dimensional high-speed video recording camera. It consists of linear-image sensor, frame memory and personal computer. This linear-image sensor scans object image one-dimensionally at the rate of 2MHz(maximum). At the maximum speed, sampling clock is 2.048 MHz, so shortest sampling period between line-scannings is 250 micro seconds. This is not so high speed compared with traditional streak camera. But resulting images can be digitized and stored in the memory. Therefore various image-analysis can be performed with personal computer. Experiment was performed to test this video-recording camera. The object was free-fall of a steel ball, which diameter was 30mm. The video-camera was operated at 512KHz to 2.048MHz. The resultant trajectory stored on frame-memory was time-displacement characteristic of object. In addition movement of blades of focal-plane shutter were recorded and analyzed.

In this paper, after discribing the relationship between subjective clarity and frame frequency of television when the image signal bandwidth is constant, HSTV-2 system used in motion analysis is introduced.

A high speed pulsed light generator system has been developed for the optical analysis and imaging of fast processes in fluid dynamics. As a light source, one or more high power LEDs are used. The maximum light power extracted out of one diode is 1 Watt. The pulse repetition rate is up to 2.MHz and the pulse width can be adjusted in the range from 50 ns to 10 4s. The light emitted from the diodes has a wavelength of 660 nm. Due to its pronounced coherence, it is especially suited for the observation of phase objects by interferometric methods. Examples for the application of the generator are presented.

To investigate the penetration and the spreading of diesel injection jet in a combustion chamber the high speed cinematograhy is particularly qualified. Because the velocity of the jet is very fast and the growing droplets are very small, highest time resolution and optical resolution are necassary. Therefore a test set up with a special rotating mirror camera was developed. With this arangement new knowledge on penetration and spreading of an injection jet was obtained.

The design details and performance characteristics of two soft x-ray streak camera systems developed at Max-Planck Institut fur Quantenoptik are reported. The main design considerations are compactness, versatility and reliability. The camera consists of an image converter tube, an image intensifier and data recording unit . Both systems are equipped with open all metal image converter tube of our own design. The first system (XRSC-I) has a Photochron type electron-optical design and its image converter tube is optically coupled to a four-stage magnetically focused image intensifier. The electron-optical design of the second system (XRSC-II) is simpler and uses equidiameter cylindrical electrodes. Furthermore, its image intensifier is electrostatically focused with channel plates and fiber-optic windows. The x-ray streak camera systems have been combined with a free standing transmission grating for time-resolved x-ray spectroscopy of laser-produced plasmas. Results from these experiments are presented to illustrate the usefulness of the instrument.

A fiberoptic sensor for electric fieldstrength measurements was developed. This sensor allows to measure even high electric fields in a contactless way, therefore nearly undisturbing the phenomenon to be measured. The basic idea is to rotate the polarization plane of linearly polarized light in an optically active medium (linear electrooptic effect). Further advantages of this method are: high bandwidth near the GHz-region, high local resolution because of small size, no electromagnetic pulse disturbance, useable in high field regions, where electrical methods fail, even in rigid environments. The fiberoptic sensor together with the detector system, which comprises a streakcamera with an image processing system, allows the analog data aquisition and -transmission of about 40 time synchronised signals at one shot using fiberoptics. The application and results of the new diagnostic in the case of the Pseudo Spark Chamber, where classical electric measurements fail, will be presented. The Pseudo Spark1 is a hollow cathode, low pressure gas discharge system, in a special rotational symmetric geometrie. It is situated on the left hand side of the Paschen curve by about 20 Pa hydrogen. During the dicharge there is observed a well pinched electron beam as well as an ion beam; also various kinds of X-ray emission can be detected. The applications of this systems are in Pulse Power technology, lithography, as well as high power switching and material processing.

The high speed imaging system of pulse nuclear radiation source consists of pinhole imaging, ultrafast fluorescent materials, electron optical shutter and high speed TV techniques. We have successfully carried out a research into a high speed framing imaging system. This system has been used in both laboratory and underground nuclear test measurements. Spatial and temporal resolutions of the system are better than 0.5 mm and 5 ns respectively. The principle and applications of the system will be described in the paper.

A method of high speed photography is presented. It was designed and performed in order to study temporal behaviours of plasma closure effects of pinhole targets in laser plasma experiments. A series of high speed photographs were taken for the laser beam transmitted through the pinhole targets. Spatially resolved and integrated temporal histories of closure effects were observed, respectively. Some physical information about closure effect, for example, closure speed and so on was studied.

In this paper, some main developments obtained during past thirty years in the studies of high speed photography and photonics application technology in explosion, shock and other fast process are presented. Key Words: photonics, High speed photography, explosion, optical diagnostic, image processing

High-speed photographic studies, made at a framing speed of 1 million per second, of the oblique impact of 2mm diameter tungsten carbide spheres on blocks of soda-lime glass are described. The oblique impact causes sliding, which has a very marked influence on the orientation of the Hertzian cone crack with respect to the surface normal. An explanation of this effect is also provided.

The sequently pulsed laser can send out an array narrow pulsed laser. It is used not only as the illumination of source but also as the high speed shutter and the frame camera. Using the system of laser high speed photography (SLHSP), a series of experiments have been finished in explosive measurement. The results from experiment are analysed and handled.

Experimental results are presented to study the phenomena of both normal and oblique impact of flat-nosed projectiles on metallic plates, a domain where almost no test data is available. Aluminum and copper strikers of 20 mm nominal diameter were used at normal incidence for both steel and copper targets with thicknesses from 10 to 30 mm. Impact velocities ranged from 300 to 1200 m/s. Steel strikers of 20 mm nominal diameter were fired at aluminum targets. Impact velocities ranged from 350 to 900 m/s, and target obliquity was varied from 0° to 50°. Projectile and target deformations were examined, and the effect of obliquity was shown.

In order to expand the application of a high-speed rotating mirror camera, some high-speed photographic techniques including a magnification optics system, a turning mechanism, a transmitting-type schlieren system and a multi-channel fibreoptical sensor have been developed. The detail of these techniques and results from experiments are described in this paper. It's well known that a high-speed rotating mirror camera is an important optical instrument with a high space-time resolution. It has widely been used in fields of explosion mechanics, high-velocity impacts, plasma physics, electrical pulse discharge and so on. In 1958, Northwest Optical Factory and the others in China started to develop the camera and to produce it on a small scale for use. In 1962, Xian Institute of Optics and Precision Mechanics was established. After that time, most of the researching work about high-speed rotating mirror cameras have been charged by the Institute. However, the others have also made some special cameras according to their own need. In order to expand the applications of high-speed rotating mirror camera, various additional optical equipment has been made to satisfy different demand. A part of additional equipment is as follows.

A transient ultrasonic spectroscopy system has been developed using a sound pulse generated by a metal explosion and optical detection of the sound. The electric explosion of metal wire produces a short-duration acoustic pulse containing a broad Fourier frequency spectrum in the range 10 to 200 kHz. The acoustic pulse profiles at two distances are monitored by the transient photorefractive deflection of collimated probe laser beams, one of which is displaced from but parallel to the other. An angular magnification(an increase in sensitivity of detection) of the deflection is achieved by refracting the deflected laser beam through a peripheral section of a converging lens. The transient deflection is observed by using a knife-edge to block half of the probe beam and detecting the signal with a fast photodiode. By taking the difference between the electronic signal outputs of the two photodiodes, a pair of noise free transient deflection signals is recorded. Fourier analysis of these probe deflection signals provides the absorption spectrum, and an example for atmospheric air is given. The experimental results are attributed to combined absorption due to the classical effects of thermal conduction and viscosity, absorption due to rotational relaxation and due to the humidity dependent vibrational relaxation of nitrogen and oxygen.

This paper describes an optical method for measuring shock wave velocity and plasma temperature preduced by gold wire explosion in air and the full initiation process of No.2 explosive by the gold wire explosion. The accumulation area of EBW detonator, threshold initiation phenomenon and its judgment and functional relation between real and visional detonation velocities have been investigated. The initiation mechanism of the detonator has also been put forward.

Detonating explosives were used to induce high intensity stress waves in geologic materials. The method of loading the sample materials involved emplacing a cylindrical explosive charge in contact with one end of the specimen. To observe the wave propagation phenomena, the slit of a high speed streak camera was aligned with the axis of the explosive and geologic sample. A series of gridlines painted on the surface of the specimens enabled clear observation of stress wave propagation and subsequent material motion. The decay of peak stress along the axis of the loaded sample and the ability to simultaneously determine the volumetric strain levels provided a unique method of obtaining a complete dynamic stress-strain curve on each experiment. The experimental data were taken on 5 rock types having a wide range of mechanical properties. The observed stress wave intensities were in the range from 1 to 50 kilobars. The strain amplitudes were from 0.6 to 25 percent. The characteristic impedance of the rocks studied varied between 2.2 and 11.4 megarayls. The detonation impedances of the explosives used were 7.7 and 13.3 megarayls. In some cases, the observed wave travelled slower than the statically determined elastic wave speed, indicating plastic wave propagation. The information provided by this high speed photographic method is useful in understanding the initial material behavior of the dynamic stress wave propagation induced in rock media from detonating explosives.

The techniques of moire photography and high speed photography have been combined to measure transient displacement fields. Sequences of double exposure moire photographs of cracks moving through plates of polymethylmethacrylate (PMMA) were recorded with a rotating mirror camera at 2µs frame-1. One sequence was analysed in detail to reveal the time variation of both in-plane displacement components, and the dynamic stress intensity factor (Kld). An alternative approach, based on recording real-time moire fringes, allowed the spatial frequency of the specimen grating to be increased to 150 lines per mm (l mm-1), and was used to visualise the deformation caused by solid particle impact. Laser speckle photography with a double pulsed ruby laser has also been investigated as a noncontacting alternative to moire.

Microcirculation is the basic functional unit of blood circulation in human body. The oxygen needed and the carbon dioxide discharged in human body were accomplished in the case of flow and deformation of red blood cells (RBC) in capillaries. The rheology of RBC performs an important function for maintaining normal blood irrigation and nutritional metabolism. Obviously, for blood irrigation, dynamic mechanism of RBC, blood cell microrheology, law of mivrocirculation and cause of disease, it has very important significance to study quantitatively the rheology of RBC in the capillaries of live animal. In recent years, Tianjin University, cooperating with the Institute of Hematology, used the method of high speed photomicrography to record the flow states of RBC in the capillaries of the hamster cheek pouch and the frog web. Some systems were assembled through the study of luminous energy transmission, illumination system and optical match. These systems included the microhigh-speed camera system, the microhighspeed video recorder system and the microhighspeed camera system combining with an image enhancement tube. Some useful results were obtained by the photography of the flow states of RBC, film analysis and data processing. These results provided the beneficial data for the dynamic mechanism that RBC were deformed by the different blood flow field.

Lawrence Livermore National Laboratory's (LLNL's) High-Speed Microphotographic Laboratory provides a facility for studying rapidly evolving microstructures. In particular, the exploding of wires and foils and their interactions with high explosives are of particular interest. The facility combines high-speed electronic framing and streak cameras with the appropriate specialized optics, spectrographs, and laser illumination to record events with a few nanoseconds and micrometers of temporal and spatial resolutions, respectively. Velocity and spectral data are also used to compute pressures with better than kilobar resolution.

The purpose of this project was to develop a high speed photography system for studying the performance of parallel hole opening-cuts. To facilitate the filming, where a speed of maximum 500 f/s was used, the opening cuts were drilled in open air in a vertical wall in a quarry. The method to use high speed photography worked very well and we observed that the performance of the parallel hole opening-cuts was not always as expected even if the blasting often led to the planned result.

In this paper, high speed micrography as applied to metallogical observation has been discussed. It is possible to observe metal surface in motion with a time sesolution of a few microseconds and a magnification of several ten times. As an application of it, we have observed behaviour of Fe-3%Si alloy surface under antomodulation in order to investigate a relation between automodulation generation and nonlinearlity of the alloy, which has already predicted theoretically. Up to the present day, the evidence has not yet been found out from the experiment performed so far.

We have developed new pseudo-colored Schlieren method. We tried to improve the multicolored grid, in there is not overlapping part between the spectral transmittance of each stripes. This method apply to density change of shock wave propagating through air. As a result of this study, it is clear that this method have the advantage as follows; (1) It is judged from the order of color stripes whether an arbitrary region expands or compresses in comparison with initial state. (2) This method is useful for measurment in wide region of density gradient change.

A large amount of experiments have demonstrated that Direct Linear Transtormations (DLT) can be used to process the observations of the high-speed stereophotography in explosion processes. An accuracy of 2-3 cm can be obtained under the following conditions, photoscale 1: 1000; simultaneous exposure frequency 1000HZ; about the same elevation of two cameras; the intersecting angle of two principal optical axes 30°-75°; better distribution of the control points. Also the accuracy can be up to the order of a few decimeters even if the elevation difference of two cameras is relatively large, the intersecting angle is as small as 7.5°, and no control points in the target area. The intersecting angle has a significant influence on the accuracy of X-coordinates, and the larger elevation difference of the two cameras damages the accuracy of Z-coordinates. Nevertheless, the distribution of the control points have an important effect on the accuracy of X-,Y-,and Z-coordinates, as a result, that no control points exist in the explosion area, or cotrol points are available in one horizontal plane should be avoided.

The experimental pulsed X-ray device with a picosecond time resolution is described, in which a gas-discharge converter of X-ray images is used as an X-ray image recorder.

The construction of the pulse generator feeding an X-ray tube with the voltage amplitude up to 150 kV and the pulse duration from 200 to 500 ps at a half height, operating with the frequency 10 Hz is described. The scheme and the results of parameter measurement of PS pulses feeding an X-ray tube are given, the main requirements to the measuring device elements are considered.