The pulsed characteristics of gated, microstrip configuration microchannel-plate (MCP) detectors used in x-ray framing cameras deployed on laser plasma experiments worldwide are examined in greater detail. The detectors are calibrated using short (20 ps) and long (500 ps) pulse x-ray irradiation and 3 - 60 ps, deep UV (202 and 213 nm), spatially-smoothed laser irradiation. Two-dimensional unsaturated gain profiles show < 5% long-range transverse variations but up to 3 dB/cm drop in gain parallel to the pulse propagation direction. Up to 50% gain enhancements due to voltage reflection from the bends of a meander stripline geometry and from the ends of conventional straight striplines are also observed. Reproducible gate profiles are obtained with either picosecond x-ray or UV bursts and FWHM extracted with 3 picosecond accuracy. A novel single-shot method for measuring local gate propagation speeds using a tilted MCP is also demonstrated.

Thomson-CSF is introducing a new camera, the NUCAM TSN 906, especially designed for measurement of ultra-fast light phenomena. The camera features a temporal resolution of less than three picoseconds over a broad light spectrum by the utilization of photocathode S20, S25, or S1. This camera is designed for ease of use in industrial as well as laboratory environments. In previous camera generations, the image was either acquired on photographic film or through adaptation of an external video camera. With the TSN 906, electronic image acquisition is standard, creating ease of use. NUCAM integrates an intensified image converter tube, 512 X 512 pixel CCD sensor, image memory and GPIB in the same case. This original design produces a very compact and low cost camera. The camera can be used locally by displaying the image on a video monitor or remote controlled via a microcomputer installed with an interface board and control software.

This paper presents a new design and measured data of a femtosecond streak camera. In order to reduce the temporal dispersion of photoelectrons in the new streak tube, an acceleration electric field near the photocathode was achieved to 8.75 kV/mm applying a high voltage pulse to the dc biased-photocathode. We have developed a high speed deflection circuit and a meander-type traveling wave deflector, and obtained high sweep speed of 8.76 X 10⁸ m/s on the phosphor screen. A temporal resolution of 180 fs was obtained with 100 photoelectrons using colliding-pulse passively modelocked ring dye laser for the light source. Dynamic ranges of 10 and 20 were achieved at the temporal resolutions of 200 fs and 330 fs, respectively.

A time-, position-, and energy-resolved soft x-ray (100-500 eV) diagnostic is being developed for PBFA II target experiments. The diagnostic provides measurements of hydrodynamic motion and thermal gradients in light-ion fusion targets. A slit-image of the x-ray source is imprinted onto thin sheets of organic scintillator to create a 1D image. The scintillator light is then proximity-coupled to a linear array of fiber-optics that transports the light to a streak camera operated without an intensifier. The streak camera output is recorded on a CCD camera. We are characterizing the spatial and temporal resolutions of the systems. Data is collected from as many as 90 individual fibers and corrected for variations in throughput and to roughly 5% standard deviation in their relative throughput. Spatial resolution of these systems at the source is approximately -.4 mm. Timing resolution is nominally 2 ns and is limited primarily by the scintillator response and dispersion in the 50-m-long fiber array. We describe the measurement techniques and the results of the characterization.

This paper presents the results obtained with an architecture using a Mach-Zehnder differential modulator at 800 nm. The measured performance, i.e., 6 GHz bandwidth, sampling rate of 100 Gsamples/s, signal/noise 33 to 36 dB, is compared with theoretical performance. In particular, a correction method for reducing laser source noise was tested and enabled results close to calculated estimates.

This paper surveys the varied applications of imaging technologies used in space experiment studies. Emphasis is on the most recent imaging programs including the Solid Surface Combustion Experiments, Surface Tension Driven Convection Experiment, Pool Boiling Experiment, Droplet Combustion Experiment and Smoldering Combustion Experiment programs.

A VISAR (velocity interferometer system for any reflector) determines the velocity of a moving object by measuring the Doppler shift with an unequal path length interferometer. This paper analyzes the configuration in the case where the optics are not perfect, (i.e., beam splitters not 50%, waveplates not exact or misaligned, improper polarization, etc.). It is shown that perfect interferometric information can be recovered even with far from perfect optical components.

A modified Cranz-Schardin camera is presented that records simultaneously both the isochromatic patterns of dynamic photoelasticity and the shadow patterns of dynamic caustics, which are useful for the investigation of the interaction between the stress waves and the cracks in elastic structures. The system of spark gaps each of them consisting of four electrodes provides point flashes that are small enough in size to form the caustic patterns of good quality and intense enough in light for the recording of the isochromatic patterns of photoelasticity. A chip-microprocessor and some other hardware elements are used in the control system for the time setting of the first delay and variated frame intervals. With the help of a partial reflecting mirror the caustic pattern and the isochromatic patterns are recorded simultaneously with separated films. Some results of the recorded patterns are given to show the validity of this system.

We describe a new fluorescence microscope system, which is the third generation of our pulsed-laser microscope systems developed for the purpose of capturing rapid cellular phenomena. Time resolution of this latest version is supported by the combination of a Q- switched Nd:YAG laser producing a burst of 4 pulses and a large format framing camera. We obtain series images at intervals on the order of 10 microsecond(s) with exposure times of 30 ns. With this multi-shot pulsed laser fluorescence microscope system, we examined the behavior of the transmembrane potential in a sea urchin egg under an intense electric field. Irreversible process of cell electroporation was revealed in serial images taken under a single electric pulse of microsecond duration.

A cross-correlation technique for the measurement of timing jitter of femtosecond light pulses in time domain is presented. This measurement technique uses an optical mixing process in a scanned Michelson interferometer, which is simple in application but has femtosecond temporal resolution. The width of autocorrelated pulse and the width of pulse by cross- correlating with the next pulse following after the external cavity round trip time were measured. Timing jitter of the light pulses from the actively mode-locked semiconductor laser was measured by comparing the above two pulse widths, and the timing jitter was found to be approximately 15 fs for a pulse having approximately 270 fs FWHM width.

The construction and the fundamental studies of a kilohertz-range flash x-ray generator utilizing a hot-cathode triode for high-speed radiography are described. This generator consisted of the following components: a constant high-voltage power supply, an energy- storage main condenser of 97 nF, a grid pulser, and an x-ray tube. The x-ray tube was of an enclosed-triode type and was composed of the following major parts: an anode rod made of copper, a plane anode tip (target) made of tungsten, a focusing electrode made of iron, a hot cathode (filament) made from a tungsten wire, a tungsten grid, and a glass tube body. The main condenser was charged from 50 to 70 kV, and the electric charges in the condenser were discharged repetitively by the grid pulser. The temperature of the cathode was about 2,000 K, and the cathode current was primarily controlled by the grid voltage at a constant filament temperature. The pulse width was less than 2 microsecond(s) , and the maximum repetition rate was about 30 kHz. The x-ray intensity was 67.3 nC/kg at 0.5 m per pulse with a peak grid voltage of 1.2 kV and a charged voltage of main condenser of 70 kV.

Radiographic image simulations using a spectrum simulation system SPECTRA are presented. SPECTRA calculated the x-ray spectra using the data of tube voltage and current obtained from a soft flash x-ray generator. The x-ray generator used in the present work consisted of a high-voltage power supply, an oil condenser of 10 nF, a turbo molecular pump, a thyristor pulser as a trigger device, and a cold-cathode triode. After the main condenser was charged from 60 to 80 kV, the electric charges in the condenser were discharged. We obtained the maximum tube voltage which was equivalent to the initial charged voltage in the condenser. Bremsstrahlung x-ray intensities were derived from the Kramers' empirical equation and the intensities of the characteristic x rays were approximately calculated on the basis of the experimental results by Birch and Marshall. In the present work, we used two 3-dimensional models provided by SPECTRA as radiographed objects. We saved the measured data of the tube voltage and current for the flash x rays with charged voltages of 60, 70, and 80 kV. Then, assuming that these flash x rays were applied to the above models at a distance of 1 m, we obtained simulated images with filtration of aluminum. The obtained images fairly agreed with real radiographs which were achieved with a Computed Radiography system.

We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response < 25 ps FWHM. A thin piece of scintillator material acts as a neutron-to-light converter. A zoom lens images light from the scintillator surface to a high-speed (15 ps) optical streak camera for recording. The zoom lens allows the scintillator to be positioned between 1 and 50 cm from a target. The camera simultaneously records an optical fiducial pulse which allows the camera time base to be calibrated relative to the incident laser power. Bursts of x rays formed by focusing 20 ps, 2.5 TW laser pulses onto gold disk targets demonstrate the detector resolution to be < 25 ps. We have recorded burn histories for deuterium/tritium-filled targets producing as few as 3 X 10⁷ neutrons.

The imaging performance of an 8-port Full Frame Transfer Charge Coupled Device (FFT CCD) as a function of several parameters including pixel clock rate is presented. The device, model CCD-13, manufactured by English Electric Valve (EEV), is a 512 X 512 pixel array designed with four individual programmable bidirectional serial registers and eight output amplifiers permitting simultaneous readout of eight segments (128 horizontal X 256 vertical pixels) of the array. The imager was evaluated in Los Alamos National Laboratory's High-Speed Solid-State Imager Test Station at true pixel rates as high as 50 MHz for effective imager pixel rates approaching 400 MHz from multiporting. Key response characteristics measured include absolute responsivity, Charge-Transfer-Efficiency (CTE), dynamic range, resolution, signal-to-noise ratio, and electronic and optical crosstalk among the eight video channels. Preliminary test results and data obtained from the CCD-13 are presented and the versatility/capabilities of the test station are reviewed.

High frame rate CCD video cameras require high clock frequencies for running photocharge transport registers, especially when the sensor has only a single video port. It was found that some sensors of the interline transfer architecture allow for horizontal charge transport clock rates in excess of 75 MHz while still producing images of acceptable quality. We describe a relatively inexpensive method for analog-to-digital processing of video images at rates of 75 MSPS and 10-bit range. Images are stored in a fast, 512 X 512 X 12 kbit random access memory (RAM). Upon the data transfer into a processor, the public domain `NIH IMAGE' software is used for image analysis.

A 2/3 inch format charge coupled device (CCD) image sensor has been developed for high speed imaging. Designed on a sixteen micron square pixel pitch with 512(H) X 512(V) active pixels, the array provides full resolution at 1,000 frames per second. Other performance parameters include 65 dB dynamic range and greater than 1,000 times blooming suppression. Fabrication is based on a triple poly-buried channel CCD process, with two active metal layers. This work details the essential design features and reports results of our preliminary evaluation.

A versatile new camera, the Los Alamos National Laboratory (LANL) model GY6, is described. It operates at a wide variety of frame rates, from RS-170 to 700 frames per second. The camera operates as an NTSC compatible black and white camera when operating at RS- 170 rates. When used for variable high-frame rates, a simple substitution is made of the RS- 170 sync/clock generator circuit card with a high speed emitter-coupled logic (ECL) circuit card.