Image Converter Tube Research Articles

Calculating the range of observation for an active-pulse television system

This paper discusses an active-pulse television system (APTVS) intended for the observation of objects illuminated by laser radiation. The operating range of an APTVS is estimated for the case in which it uses an image converter tube with an oxygen-silver-cesium photocathode and laser illumination at wavelengths of 0.82, 1.06, and 1.57 µm. © 2005 Optical Society of America

A Streak-Camera Monitor for Hard X Rays

The instrument is designed on the basis of a fast scintillator and a high-speed image-converter tube for hard X and γ rays (≥10 keV). Using a scintillator, it is possible to obtain an almost constant spectral response over an energy range of 40–1000 keV. The time resolution of the camera is governed by the luminescence decay time in the scintillator and may go as high as 100–150 ps. The instrument is used at the ISKRA-5 facility to detect pulses of hard X rays.

A Streak-Camera Neutron Monitor

The principle of a high-speed neutron monitor is based on neutron–proton conversion in a polyethylene converter. Protons thus produced are detected by an X-ray image-converter tube with a CsI photocathode. The monitor efficiency is 1.5 × 10–3, its time resolution is ∼30 ps, and its spatial resolution is ≥100 μm. The instrument is used to measure the time parameters of neutron fluxes in the ISKRA installations.

Academician A M Prokhorov and femto — attosecond photoelectronics

High-speed photography using time-analysing image-converter tubes (ICTs) occupies a worthy place among a variety of scientific fields whose development is closely associated with the name of academician A.M. Prokhorov. It was A.M. Prokhorov who headed in our country from the mid-1960s until the first years of a new century the studies of fundamental processes underlying high-speed image-tube photography. He organised an international cooperation aimed at the development and application of the methods and means for high-speed image-tube diagnostics in laser physics. He provided the conditions for the development of competitive ICTs, diffractometers, and image-converter cameras (ICCs) and for their successful applications in quantum electronics, nonlinear and fibre optics, laser plasma physics, and controlled nuclear fusion. A new scientific field — femto — attosecond photoelectronics was initiated under his influence and is being successfully developed now.

Position-sensitive ionization detectors for ionizing beams diagnostics

Ionizing detectors for on-line non-destructive monitoring of the geometric parameters of ionizing beams have been proposed. Such a detector can be used on a beamline with a residual gas pressure of about 10 −3–10 −6 Torr. It measures the product of ionization of the residual gas by the beam under investigation. An electric field moves the ions through a narrow slit into an analyzer. The analyzer field transforms the energy distribution of the ions into a two-dimensional space distribution on the outer analyzer plane. An Open Image Converter Tube (ICT) with an amplifier consisting of two Micro Channel Plates (MCP) forms an image of the real beam cross-section. This image is registered by a video camera, processed and stored on a computer. The detectors were successfully tested on beams of charged particles with wide energy and intensity ranges and on synchrotron radiation beams. Codes developed give the distribution of the beam density along its cross-section, beam profiles, the position of the center of gravity and its displacement. Statistical processing increases the signal/background ratio more than 10 times, and evaluates the position of the center of gravity with an uncertainty of about 1 μm.

Night-vision device-rangefinder based on a biplanar direct-transfer image-converter tube

Night-vision device-rangefinder based on a biplanar direct-transfer image-converter tube

Pico-femtosecond image-tube photography in quantum electronics

The possibility of experimental achievement of the time resolution of image-converter tubes (ICTs) corresponding to the theoretical limit of 10 fs is considered as applied to quantum electronics problems. A new generation of ICTs with a temporal resolution of 200 — 500 fs has been developed for recording femtosecond laser radiation. The entirely new devices based on time-analysing ICTs such as femtosecond photoelectronic diffractometers, have been created for studying the dynamics of phase transitions in substances using diffrac-tion of electrons with energies ranging from 20 to 40 keV.

Diagnostic arrangement on S-300 facility

A set of experiments on neutron and x-ray generation was performed on the S-300 facility for the last few months. The S-300 facility is a pulse generator with electric current achieving 3.5 MA, voltage 400–500 kV, and rise time ∼100 ns. (Chernenko et al., Proc. of the 11th International Conference of Power Particle Beams, Prague, 1966, p. 154). It is designed as van eight-module machine transmitting electromagnetic power to the low-inductive load through the vacuum line with self-magnetic isolation. Diagnostic techniques and methods on S-300 used are described in this article. Ten-channel polychromator is used for the soft x-ray and vacuum ultraviolet bands (50–500 eV) measurements with spectral resolution of 5%–20% and time resolution less than 2.5 ns. Radiated power measurements in the region of 0.1–10 keV are performed by vacuum x-ray diodes and semiconductor detectors equipped with different filters. Curved crystal x-ray spectrography is intended for plasma density, electron, and ion temperature evaluation. Visible and x-ray radiation image converter tubes and a streak camera reproduce plasma dynamics. Laser shadow and schlieren probing are used to investigate rare periphery plasma motion. Time-of-flight and activation technique is designed for total neutron yield determination.

Two-dimensional microtarget imaging with continuous time-base sweep

A technique for two-dimensional imaging of an x-ray source with a continuous time-base sweep is described. The technique is based on the use of an x-ray image converter tube in combination with a pinhole camera, which has a linear pinhole array. The basic relationships for determining the parameters of the recording system are given. Setting up the procedure is described and the results of two-dimensional microtarget imaging with a continuous time-base sweep in an experiment at the 'Iskra-4' laser facility are presented.

Numeric estimation of the possibilities of ionizing detectors for monitoring SR beam space parameters

An ionizing detector for on-line registration and representation of the geometric SR beam parameters was developed in RRC KI. The detector analyses the products of the residual gas ionization, which was done by the investigated beam. Special electrostatic optics and open image converter tube (ICT) form optical image of the real beam on the screen of ICT. The detector was checked on SR beams of the next storage rings: DCI (LURE, Orsey, France), KSRS (RRC KI, Moscow, Russia) and MAX-2 (MAX-lab, Lund, Sweden). The codes for TV image processing give a possibility for numeric estimation of the beam size, the width of its horizontal and vertical profiles and position of the beam gravity. Statistic processing of the beam gravity center using big amount of TV frames gives uncertainty in the beam position of about 2 μm while the width of the beam is about 2 mm. Summation of big amount of TV frames was used. This method significantly increases signal-to-noise ratio.

A new optical oscilloscope

A new optical oscilloscope has been developed on the basis of the image-converter tube camera technology. Optical or electrical pulses in single or repetitive mode can be tested. When single pulse without time dependence on the sweep circuit is tested, an optical-fiber delay unit is adopted to ensure the pulse is captured. The optical oscilloscope works at a fixed frequency while repetitive pulses of any frequency less than 20 GHz were tested. A newly designed photocathode optical oscilloscope tube, control circuits, and a linear charge-coupled device readout system have been incorporated into the optical oscilloscope. Experimental results show that the temporal resolution of the optical oscilloscope is better than 5 ps, the spectral response range is 380–850 nm, and the single pulse can be captured with the probability of 100%.

An image converting system in framing and streak mode for impulsive soft x-ray observation

A high-speed image converting system is described. The system is capable of display both in multiframing- and streak-mode image for a pulsed x-ray source. The system relies on a new concept without employing an image converter tube. To achieve both temporally and spatially resolved display, the image of the x-ray source is acquired with a pinhole camera and with multichannel arrayed scintillator–photomultiplier combinations, which are used complementarily. The temporal resolution is 3 ns. This system is successfully used to observe the time evolution of soft x-ray emissions around 4 Å in plasma focus discharges with puffed Ar.

Physical conditions in neutral gas atmosphere of P/Halley (1986 III) on the basis of spectral observations

Abstract On the basis of over 40 spectra of comet P/Halley (1986 III) obtained with the 1 m Zeiss reflector and the image-converter tube camera in Assy physical parameters of cometary gas ( Q is the gas production, τ is the lifetime and ν is the velocity of molecules C 2 , C 3 and CN in the neutral coma) were obtained. The low velocities of the CN molecules compared to the velocities of C 2 and C 3 molecules are probably connected to the presence of the extensive source of parental molecules, from the latter as a result of photodissociation CN molecules being generated (CN-jets, CHON-particles).

Transmission characteristics of image-converter tubes

Abstract A numerical model representing the performance of image-converter tubes is presented.

Development of high resolution thin film patterns on curved photocathode substrates of image tubes

Fabrication of thin film patterns involves a sequence of photolithographic and chemical processes to define the high resolution features in thin films on the surface of the optical substrates. The substrates used in the present work were curved fused silica with radii of curvature 58 mm and 18 mm which are used as photocathode substrates for image converter and image intensifier tube devices. The resolution pattern and bar chart were successfully printed on these substrates using a secondary conformable photomask of Mylar.

Electron-optical zooming using a modified image tube configuration

An electrostatic image converter tube geometry (model 6914) has been modified as a four-electrode configuration to provide electron-optical zooming. The zoom lens action is effected by the principle of anode space zooming. A zooming factor of 2.8 has been achieved using an image tube assembly with a resolution of about 30 line-pairs/mm, in an electron-optical demountable system. Gold photocathodes with a printed resolution pattern were used for this study. An interpretation of the observed electron-optical zooming action has been given in terms of gaussian optics. The results of some zoom image tubes having patterned cathode substrates on which Cs3Sb photocathodes has been processed are also presented.

Registration, storage, and processing of Fabry–Perot ring spectra by a diode matrix combined with a microcomputer

A combination of a 32×32-element silicon-diode matrix and an Apple II computer is used to record and analyze Fabry–Perot interference ring patterns. The main advantage over conventional methods consists in the possibility of selecting the spectral resolution after registration and in the absence of alignment problems. Application of an image converter tube with VUV transmitting window in front of the matrix extends the applicability of the device to UV and VUV spectra.

Optimization considerations in the design of active night viewing systems

The problems associated with the optimization of the design of active night viewing systems based on the infra-red image converter tube are discussed with special reference to its key components; namely the optics, the imaging device and the infra-red source. The role of spectral matching between the response of the imaging device and the distribution of the infra-red source is highlighted, and these factors pertaining to some practical sources in combination with the imaging device are computed. A procedure for the design of an infra-red source to achieve a specified field irradiance is presented, and the use of these concepts in the optimization of the design of practical systems is illustrated.

S1 photocathode designed for streak camera image converter tubes

Semitransparent S1 photocathodes have been developed on a low-resistivity SnO2 layer for streak camera image converter tubes. The 50-Ω/⧠ resistivity combined with good photocathode sensitivity prevents parasitic effects and provides an efficient diagnosis tool for 1.06-μm laser–plasma interaction experiments. Furthermore, the lifetime in the 1-μm range has been greatly increased by a rebaking process which may reestablish the 1.06-μm sensitivity.

Evaluation of Parameters of the Image Converter Tube

Some common procedures for the evaluation of the parameters of the image converter tube are analyzed on the basis of the physical processes involved in their definition and measurement. A correlation between these procedures is established with a view to facilitate a comparison and selection of image converter tubes in the design of active night viewing systems. Experimental results verifying the correlation are presented. A calibration procedure is suggested and it is shown that it results in precise measurement of conversion gain.