Image Converter Tube Research Articles

Optimal Imaging Magnetic Field of Pulse-Dilation Framing Image Converter Tube

Optimal Imaging Magnetic Field of Pulse-Dilation Framing Image Converter Tube

X-ray streak camera tube with two photocathodes

<sec>The time-resolved X-ray spectroscopy measurement system based on X-ray streak camera technology is indispensable diagnostic equipment in the study of laser inertial fusion research and high-energy-density physics. However, limited by the effective photocathode length of the X-ray streak tube, the time-resolved spectral measurement system usually used has the shortcomings of narrow spectrum range and poor spectral resolution.</sec><sec>In order to overcome the shortcomings, a novel dual-channel streak tube is developed, which consists of a photocathode, a prefocusing electrode group in temporal direction, an electric quadrupole lens electrode group, a main focusing electrode group in temporal direction, a deflector plate, and a phosphor screen. The photocathode has two slits. When X-rays are incident, two electron beams can be emitted simultaneously. The electric quadrupole lens electrode group is composed of 8 arc electrodes. Two electric quadrupole lenses are formed by the 8 arc electrodes in the spatial direction. Two electron beams emitted from the cathode of the streak tube are first accelerated and prefocused by the prefocusing electrode group in the time direction, and then compressed by the main focusing electrode group in the time direction. In the spatial direction, two electron beams are focused by the two electric quadrupole lenses independently. This novel streak tube structure can focus two electron beams at the same time, thereby increasing the effective photocathode length and maintaining the compact structure of streak tube without increasing the aberration.</sec><sec>The cathode voltage of the designed streak tube is –12 kV, the distance from cathode to grid is 5 mm, and the cathode-grid field strength is 2.4 kV/mm. The cathode is divided into two sections, the spacing between sections is about 13 mm, the length of each section is more than 20 mm, the magnification of the image converter tube is about 1.56 times, the distance between the cathode and the phosphor screen is 300 mm, and the longest size along the cathode direction is 90 mm. The test results of the performance of the streak tube show that the actual effective cathode length of the developed tube reaches 44 mm, the spatial resolution is better than 15 lp/mm, and the deflection sensitivity is better than 40 mm/kV. The effective cathode and spatial resolution of the tube can be increased to 50 mm and 25 lp/mm by further optimizing the structure of the tube and removing the image intensifier with a high sensitivity image recording system, respectively.</sec>

Image converter tubes with diamond photocathodes and electron flow multipliers

The results of investigations of solar-blind image converter tubes (ICTs), sensitive in the vacuum-ultraviolet (VUV) spectral range are presented. Sensitive-conversion layers of photocathodes based on boron-doped polycrystalline diamond films were grown up on sapphire substrates for the first time. Electron flow multipliers (EFMs) were fabricated in the form of diamond grid. Solar-blind VUV ICTs without the EFM are characterized by spectral sensitivity range of 180…250 nm, estimate of the threshold sensitivity value ~10-9 W/Hz0.5 and current sensitivity ~12 - 15 mA/W. Solar-blind VUV ICTs comprising the electron flow multipliers are characterized by extended spectral sensitivity range of 180…270 nm, improved estimate of the threshold sensitivity value 10-11… 5 × 10-12 W/Hz 0.5 and current sensitivity 50 mA/W.

AUTOMATION OF CONTROL OF OPTICAL PARAMETERS OF IMAGE CONVERTER TUBES

The article proposes a scheme of an installation with a digital camera for automating the measurement viewing area picture quality and the output brightness non-uniformity ratio of an image converter tubes. The requirements for the CMOS-matrix and the lens for the digital camera used are formulated.

A Medium-Range-Energy X-Ray Source Based on an Image Converter Tube

A point source of X-ray radiation with an energy range of up to 40 keV has been developed on the basis of a specially designed image converter tube. The source is capable of operating in pulsed and continuous modes. The main purpose of this is to use the source for testing X-ray streak cameras. The device can also be used in X-ray microscopy and spectroscopy as a reference radiation source, in biomedical research, and in other fields.

Особенности характеристик солнечно-слепых электронно-оптических преобразователей с алмазными фотокатодами

The results of investigations of solar-blind image converter tubes (ICTs), sensitive in the ultraviolet spectral range are presented. Photocathodes sensitive layers of the ICT are based on boron-doped polycrystalline diamond films were grown up on sapphire substrates for the first time. Spectral range of the ICT sensitivity is 180…250 nm, the threshold sensitivity value without the electron flow multiplier ~ 10-9 W/Hz0.5 and spectral sensitivity ~ 12 - 15 mA/W.

An Image Converter Camera for Studying Processes in the Nano- and Microsecond Ranges

A chronographic image converter camera has been designed on the basis of a PIF-01 image converter tube to obtain spatial and temporal information in a study of light processes in the nano- and microsecond ranges. The duration of scans on a 25-mm-diameter screen of the camera can be varied from 0.5 to 10 µs with a limiting time resolution of 2 ns or better. Possible applications of the developed camera for spectral and time measurements of processes in real experiments on the study of electric explosion of tungsten wires are described.

A Picosecond Image-Converter Dissector with a Crossed Sweep

A dual-slit dissector operating in the crossed-sweep mode with a picosecond time resolution has been created on the basis of the PIF-01 image converter tube. The dissector is applicable to synchrotron radiation sources and electron-positron colliders when it is necessary to simultaneously record longitudinal profiles of multi-bunch beams that fill two to several hundred adjacent separatrices of an accelerator ring. Two trains of light pulses shifted in time with respect to each other have been recorded with a time resolution of 6.0 ± 0.5 ps during the dynamic tests of the developed dissector with a laser system.

短磁聚焦变像管的成像畸变分析与测试

短磁聚焦变像管的成像畸变分析与测试

磁聚焦变像管像场弯曲的改善研究

磁聚焦变像管像场弯曲的改善研究

Numerical calculation and experimental study on the image rotation angle of image converter tube using magnetic focusing

Numerical calculation and experimental study on the image rotation angle of image converter tube using magnetic focusing

A spectroscopic complex for time-resolved registration of plasma-jet parameters at the PF-3 facility

A spectroscopic complex for measuring the parameters of plasma jets that are generated in a facility of the plasma-focus type and the parameters of a stationary gas in which these jets propagate is described. The complex consists of an STE-1 crossed-dispersion spectrograph and a K008 streak camera, which is placed together with a notebook computer and a no-break power unit inside a shielding box for protection against electromagnetic noise. The K008 camera is equipped with an additional image intensifier on the basis of an EP-10 image-converter tube. The spectrum image is recorded with a standard SU-05M video camera and processed with the Klen-5m dedicated program, which automatically corrects the distortion and scan nonuniformities and subtracts regular noise. The complex makes it possible to obtain the time dependences of the intensities and shapes of several spectral lines in a range of scans from a few nanoseconds to milliseconds and to promptly tune the system to the required spectral ranges. Within one discharge of the facility, a digital image of the time-integral spectrum is simultaneously recorded in the entire visible region.

Electron beam moiré fringes imaging by image converter tube with a magnetic lens

An image converter tube with a magnetic lens was used to obtain static images of moiré fringes formed by electron beam. These moiré fringes are formed due to the interference between the anode mesh and the photocathode containing slits of various spatial frequencies. Moiré fringes are observed at an accelerating voltage of 3.5 kV requiring the magnetic excitation condition of ∼550 ampere-turns. Not only the features of the fringes are analyzed but also the change of fringe spacing as a function of the rotation angle is investigated. The experimental results are found well in agreement with the theoretical analysis. By changing the rotation angle or adjusting the excitation condition of the magnetic lens, we were able to record parallel moiré and secondary moiré fringes too. The secondary moiré fringes can be observed in the rotation angle range of −39.5° to −50.6°. The theoretical analysis indicates that the secondary moiré is formed by the interference between the photocathode slits and the 2-D periodic structure of the anode mesh. Combining our proposed moiré method with the pulse-dilation technique may potentially open the door for future applications, in various fields including, but not limited to, ultrafast electrical pulse diagnostics.

Research of a New All-Optical Solid-State Scanner Based on GaAs

Design an all-optical solid-state scanner chip, which can realize high speed light deflection in a very small space, instead of electron beam deflection scan image converter tube and opto-mechanical scanner, cancel the complicated mechanical components, use the all-optical scanning to realize the super fast phenomenon observation. The beam deflection system is based on semiconductor optical waveguide core layer carrier induced refractive index change effect to realize, its development work is mainly divided into semiconductor optical waveguide and saw prisms two parts. And through the experiment, we measured deflection angle of the scanner chip to 1053nm signal light.

Electron-optical metrology with femtosecond time resolution (theory and experiment)

The principles of simultaneous spatial and temporal focusing of photoelectron beams in nonstationary electric fields are theoretically studied and experimentally realised as applied to time-analysing image-converter tubes (ICTs). It is theoretically shown that the use of nonstationary focusing electric fields makes it possible to surpass the theoretical time resolution limit of ICTs determined for stationary fields by Zavoisky and Fanchenko in the 40s – 50s of the last century. The possibility of forming electron packets with an energy of and a subfemtosecond duration (below ) gives impetus to the development of time-resolved electron diffraction, which is a direct method of investigation of atomic-molecular dynamics in solid and gaseous media.

Static and dynamic imaging electron optics and spatial–temporal aberrations in a bi-electrode spherical concentric system with electrostatic focusing

In imaging electron optics, for a concentric spherical system composed of two spherical electrodes with electrostatic focusing, the electrostatic potential distribution and the spatial–temporal trajectory of electron motion can be expressed by analytical forms. It is naturally to take such system as an ideal model to investigate the imaging properties, as well as the spatial–temporal aberrations, to analyze its particularity and to find the clue of universalities and regularities. Research on this problem has important significance, which can afford theoretical foundation not only in studying static electron optics for the night vision devices, but also in studying dynamic electron optics for high-speed image converter tubes. In the present paper, based on the practical electron ray equation and electron motion equation for a bi-electrode concentric spherical system with electrostatic focusing, the spatial–temporal trajectories of moving electrons emitted from the photocathode have been solved, the exact and approximate formulae for image position and flight time of electrons, have been deduced. Start from solutions of spatial–temporal trajectories, the electron optical spatial–temporal properties of this system are then discussed. According to the definitions of spatial–temporal aberrations, the paraxial and geometrical lateral aberrations, as well as the paraxial and geometrical temporal aberrations, have been deduced, that are classified by the order of ε z / ϕ a c and ε r / ϕ a c .

双板电极结构X射线变像管数值模拟

双板电极结构X射线变像管数值模拟

Visualization of Propagating Ultrasonic Waves Induced by a Single Laser Pulse

We have been studying non-invasive and non-destructive methods for inspecting internal structures that use laser-induced ultrasonic waves and an optical measurement technique. As one solution, we propose a new method for determining the internal structure from images of propagating ultrasonic waves induced by a single laser pulse, using a visualization technique that uses a laser beam for illumination and an image-converter tube. In this paper, the captured images of propagating ultrasonic waves in the space-time domain with nanosecond time resolution and two-dimensional dynamic images with fifty nanosecond exposure time are presented and analyzed. This investigation demonstrates the suitability of this proposed method for industrial applications.

Image-converter tubes for lasers and lasers for image-converter tubes (operating experience of the Photoelectronics Department, GPI, RAS)

Work in the field of electron-optical diagnostics of laser-induced rapid processes performed for almost half a century at the Photoelectronics Department at the General Physics Institute, RAS, is summed up. New femtosecond image-converter tubes have been developed, which provide the time resolution no worse than 100 fs in the slit scan (streak) regime, and photoelectron guns have been built for time-resolved studies of electron diffraction. The results of recent studies on manifold (up to fifty-fold) compression of picosecond electron bunches in nonstationary focusing fields are demonstrated.

Energy transportation via MITL by the linear current flow density up to 7 MA/cm

The transmission properties of the magnetically self-insulated vacuum transporting line (MITL) were studied on the S-300 pulsed power machine (3 MA, 100 ns) at the high linear current flow density up to dI/db = 7 MA/cm. Experiments were carried out with the short line sections with 10 ÷ 15 mm length and 3 ÷ 5 mm vacuum gap. For measuring of the plasma parameters, the frame ICT photography with the nanosecond temporal resolution in the SXR range and ICT (Image Converter Tube) chronography in visible range were used. The X-ray radiation in various ranges was recorded by the XRD with thin filters (SXR) and by the semiconductor detectors (HXR). The information about current transmission efficiency was obtained by means of magnetic loops and low-inductance shunt. It was determined that dense plasma arose on both anode and cathode when the linear current flow density was low enough, dI/db ≤ 1 MA/cm. A dense plasma moves across the vacuum gap with the velocity (1 ÷ 2) × 106 cm/s. By recording the current and hard X-ray radiation it was found that electron losses in the current front did not exceed 10 ÷ 100 kA. Under strong magnetization of electrons rH = mvc/eB < d, these losses could be due to the motion of fast plasma component, which velocity exceeds 107 cm/s. Such a rare plasma sheath formed on the cathode by dI/db ≥ 1 MA/cm. Thereby the successful physical modeling of the recyclable MITL related to the Sandia Laboratories’ Conceptual Project of fusion reactor on the base of fast Z-pinch has been brought about.