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No 2 (2023)
Articles
Features of the Processes of Initiation and Development of Sparks in Microstructural Gas Detectors (Review)
Abstract
The features of the processes of initiation and development of spark discharges in microstructural gas detectors of ionizing radiation in laboratory conditions and on charged-particle beams in accelerators are considered. Such aspects as the Raether charge limit, secondary electron emission, avalanche cross-overlap, positive ion feedback, explosive electron emission, cascading of detectors, and the charge density have been analyzed in detail. The better understanding of these effects will make it possible to make a further step in the development of new-type position-sensitive gas detectors.
5-14
ТЕХНИКА ЯДЕРНОГО ЭКСПЕРИМЕНТА
Electron Noise Generated by Cosmic Muons in the RED-100 Two-Phase Xenon Emission Detector
Abstract
It is shown that the working volume of the RED-100 two-phase emission detector, which operates in a ground-based laboratory with liquid xenon used as a working substance, is a source of single-electron noise signals with a characteristic frequency of ~200 kHz. Possible mechanisms of generation of these noises and methods for their suppression are discussed.
15-23
Time and Energy Resolutions of Electromagnetic Calorimeter Prototypes Based on Lead Tungstate Crystals
Abstract
The time and energy resolutions were measured for four prototypes of the PHOS electromagnetic calorimeter for the ALICE experiment at the Large Hadron Collider at CERN. Each prototype was made up of nine identical detection elements assembled as a 3 × 3 array. The detection element was based on a lead tungstate (PbWO4) scintillating crystal with a length of 180 mm and a cross section of 22 × 22 mm2, which was viewed from its end face by a photodetector. Avalanche photodiodes and silicon photomultipliers with different active areas (Hamamatsu, Japan) were used as photodetectors. The measurements were made with the electron component of secondary particle beams of the PS proton synchrotron at CERN in the momentum range of 1−10 GeV/c at a temperature of 17.5°C.
24-34
Forward Detectors of the BM@N Facility and Response Study at a Carbon Ion Beam in the SRC Experiment
Abstract
A number of forward detectors were created when upgrading the BM@N experiment: a forward hadron calorimeter (FHCal) for measuring the energy of spectator fragments as well as a beam quartz hodoscope (FQH) and a scintillation wall (ScWall) for identifying such fragments. These detectors are intended to determine the centrality and orientation of the reaction plane as well as to study the charge distributions of spectator fragments produced in nucleus−nucleus interactions. The response of the forward detectors has been measured in the SRC experiment on the study of the short-range correlations in interactions of carbon ions with a momentum of 3.5 AGeV/c in a liquid hydrogen target.
35-45
Operating Algorithm of the Digital Module of the Device for Detecting Flight Pulse
Abstract
A method and device for detecting transit pulses in the control system of a linear electrodynamic accelerator are described. The structure of an adaptive particle detector and a principle that makes it possible to increase the reliability of detecting a pulse of the expected shape against the background of noise of various origins are presented.
46-51
Gd3Al2Ga3O12:Ce Scintillation Ceramic Elements for Measuring Ionizing Radiation in Gases and Liquids
Abstract
Samples of mesh-like scintillation ceramic elements with an intricate shape based on Gd3Al2Ga3O12:Ce garnet have been obtained for the first time by 3D-printing for use in scintillation flow detectors of α, β, and γ-ray radiations in gaseous and liquid media. A method for their production is described, results of measurements of the scintillation light yield in ceramic samples under exposure to α particles are presented, and ways of improving their scintillation characteristics are proposed. Their applicability to inhomogeneous flow scintillation cells used in high-performance liquid chromatography is discussed. The unique capabilities of the 3D-printing technology for creating intricately shaped detector elements with optimized efficiency are noted.
52-57
ЭЛЕКТРОНИКА И РАДИОТЕХНИКА
A Method for Evaluating the Generation Power of Orotrons with a Two-Row Periodic Structure in the Frequency Range of 180–400 GHz
Abstract
A method for evaluating the generation power of orotron experimental models with a two-row periodic structure (TRPS), which operate with 2 × 10–6-s duration pulses and a 0.02-s repetition period in the frequency range of 180–400 GHz, is described. To realize this method, a setup has been created for measuring the attenuation of the microwave path in a wide frequency interval (180–400 GHz) based on ОV-66 (180–260 GHz) and ОV-65 (260–360 GHz) backward-wave tubes (BWOs), which are not packed in a magnet focusing system, and the possibility of their operation in a pulse power-supply regime with a high off-duty factor is shown.
58-63
A Test Arbitrary Waveform Generator
Abstract
The results from the development of a three-channel arbitrary waveform generator with the function of a programmable power supply for setting up and debugging automatic control system boards for converter devices that require synchronization with the network are presented. The features of the device are the ability to simulate a three-phase distorted network to check and adjust the synchronization of control boards and the presence of galvanic isolation between three channels, which allows for using the generator as a power source for three-phase circuits. The generator provides the formation of output signals for each of the channels in the voltage range ±25 V with a maximum current of up to 2 A. The frequency range of alternating signals of the generator is 0.01–10 kHz. Currently, the generator is used at PAO Elektrovypryamitel to simulate dips, network distortions, and phase imbalances and to tune phase-locked loop systems and analog and digital filters.
64-72
ОБЩАЯ ЭКСПЕРИМЕНТАЛЬНАЯ ТЕХНИКА
Measuring the Spectrum of the Soft Component of X-Ray Plasma Radiation at the MIFIST-0 Tokamak
Abstract
The technique and results of measuring the soft X-ray spectra of plasma on the small spherical MIFIST-0 tokamak are presented. The measurements were carried out by the gray filter method using a multichannel spectrometer based on LiF (Mg, Ti) thermoluminescent lithium fluoride detectors. This technique made it possible to study X-ray radiation in the energy range of quanta 0.2−15 keV. The spectrum of the soft X-ray component was obtained.
73-78
Formation of Anode Plasma in an Electron Diode with an Explosive-Emission Cathode
Abstract
The results of a study of a planar vacuum diode with an explosive-emission cathode during the generation of a pulsed electron beam (250–400 keV, 100 ns, and 150 J/pulse) are presented. The formation of anode plasma during electronically stimulated desorption of molecules and impact ionization in an anode gas layer is simulated. The total charge of anode-plasma electrons was ≈10% of the electron-beam charge and corresponds to the calculated ones for a cross section of electron-stimulated desorption of (0.5–2) × 10–14 cm2. The values obtained exceed the data of others researchers due to taking the contribution of the ionization of adsorbed molecules to their desorption into account. It is shown that the thermal desorption of molecules from the anode surface and electron degassing of the anode material make a negligible contribution to the formation of the anode gas layer.
79-86
Equipment for Studying Pulsed Microplasma Processes in Aqueous Solutions
Abstract
Equipment and software have been developed for carrying out potentiometric, amperometric, and volt-amperometric measurements during pulsed microplasma oxidation in aqueous electrolyte solutions. The complex setup makes it possible to determine the rates of plasma and electrochemical processes in electrolyte solutions, the potentials for ignition and quenching of plasma discharges, the value of the time constant of the transient process, and also to investigate the effect of hydrodynamic factors on microplasma processes to determine the coating thickness and alloy type.
87-94
Focus Distortion in an Image-Converter Camera at High Scanning Speeds
Abstract
Measurements of the temporal and spatial resolution of a PS-1/S1 image-converter camera, depending on the scanning speed, were performed. The camera has a PIF-01 electron-optical converter with deflecting plates of the capacitor-type scan. It is shown that obtaining the minimum half-width of the space–time response function in two mutually perpendicular directions (time and space) can be achieved by selecting an optimal voltage at the focusing electrode. The difference between the optimal static and dynamic voltages of focusing in space and time was determined experimentally, which was 450 V for a scanning speed of 1.56 × 1010 cm/s. Computer modeling of the processes that affect the optimal resolution was performed.
95-100
ФИЗИЧЕСКИЕ ПРИБОРЫ ДЛЯ ЭКОЛОГИИ, МЕДИЦИНЫ, БИОЛОГИИ
Photoactivation Approach to the Determination of Long-lived Nickel Isotopes in NPP Structural Materials
Abstract
A photoactivation method has been developed for determining the activity of long-lived nickel isotopes by the 60Co activity in metallic structural materials of a reactor core. The error of this method is 5–10%, and the sensitivity is 0.5 Bq/g if semiconductor γ-ray spectrometers with high-purity germanium detectors are used. Following the proposed approach, it is possible to significantly simplify the identification, testing, and certification of metallic structural materials at the stage of reactor decommissioning as well as to significantly reduce the cost of these works compared to the radiochemical methods.
101-109
Remote Indicator of Fiber End Temperature for Laser Surgery
Abstract
For a laser scalpel, a method has been developed to control the temperature at the end of its optical fiber with a converter by excitation of ultrasonic pulses of longitudinal and bending waves in it and measuring the delay time of their propagation. The wedge method was used to excite ultrasonic waves at a frequency of 1.1 MHz in the fiber core using a PZT-19 piezoelectric element. Rose alloy was used as the material of the wedge, and a thin wire wound on it was used to fix it on the protective sheath of the optical fiber. Delays of ultrasonic pulses were measured by signal gating for ranges of locations corresponding to reflection from the working end of the optical fiber. When the set temperatures are exceeded, a digital signal is generated for the sound alarm and for the laser control circuit in order to reduce the radiation power.
110-114
A Nondispersive Optical Gas Sensor with Time Division Multiplexing of Reference and Active Signals
Abstract
The design of a nondispersive optical infrared gas sensor with two infrared sources and a single sensor is presented. The operation of the device with the time separation of active and reference signals is demonstrated. An additional broadband photodetector is used to control the aging of radiation sources. The sensor is designed to determine the concentration of methane in an air–gas mixture with a methane volume fraction of 2.2% at most. The proposed sensor design makes it possible to determine the concentration with an accuracy of ±0.1% of the volume fraction of methane in the temperature range from –20°C to +50°C at a temperature change rate of no more than 2°C/min.
115-121
ЛАБОРАТОРНАЯ ТЕХНИКА
Measurement of Low Polarization Losses of a Semiconductor Material in Finished Diodes
Abstract
A method for the measurement of semiconductor polarization losses in the depletion region of a finished diode is considered. It is shown that the measurement can be performed by comparing with a low-loss capacitor using general-purpose impedance meters in laboratories without stabilizing the microclimate and shielding the electromagnetic fields. To exclude the drift error under these conditions, multiple regular switching of the measurement object and low-loss capacitor is proposed. As a result, the polarization loss tangent of 1.9 × 10−4 was measured with an error of ±16%.
122-128
Time Characteristics of FEU-175 and FEU-186 Single-Electron Photomultipliers with Jitter of 0.4 ns
Abstract
The results from studying the time characteristics (counting, amplitude distributions of single-electron pulses, spread of the signal propagation time (jitter) when exposed to radiation from picosecond diode lasers in the spectral range 405–780 nm) of high-speed photomultipliers FEU-175 and FEU-186 manufactured by AO Central Research Institute Electron (St. Petersburg). FEU-175 and FEU-186, respectively, are equipped with bialkali and multialkali photocathodes; their operating spectral range is 250–650 and 250–800 nm, respectively. Signal amplification is provided by a 14-dynode multiplication system, while the rise time of the PMT impulse response does not exceed 1.5 ns and the jitter is approximately 0.4 ns. PMT data can be used as photodetectors in single-quantum kinetic spectrometers with subnanosecond resolution and in other high-speed optoelectronic recorders.
129-136
Dynamic Characteristics of Active Two-Loop Vibration Protection Devices with Suppressed Resonance of the Carrier Plate
Abstract
The dynamic characteristics of active vibration protection devices, consisting of a carrier plate (mounted on elastic supports), a symmetrical group of accelerometers, service-propulsion devices, and electrical circuits that separately control six vibration modes of the plate, are studied. The system is characterized by a phase reduction of 180° in the field of mechanical resonance of the slab and the same phase decrease caused by the electromechanical resonance of the service propulsors. In order to ensure that phase limitations do not reduce the efficiency of the device (the width of the active frequency range, the transmission coefficient of vibrations), two-loop control circuits have been developed that suppress the resonance of the carrier plate. Such devices achieve the following parameters: noise transmission coefficient ≈–60 dB, active frequency range 0.2–400 Hz for terrestrial laboratory/shop applications and 0.02–200 Hz for spacecraft applications.
137-143
Device for Polarization of Polymer Films in the Field of a Barrier Type Surface Corona Discharge
Abstract
A device for the polarization of polymer films in the electric field of a barrier-type surface corona discharge is described, and the features of its operation are considered. The possibility of obtaining a uniform distribution of the potential of charges deposited on the polymer surface is demonstrated. Using the method of X-ray phase analysis, it is shown that the proposed method of polarization makes it possible to create an electric field on the surface of a composite film of polyvinylidene fluoride + PZT-ceramic, the intensity of which is sufficient to initiate the phase transition α → β in the polymer.
144-149
ПРИБОРЫ, ИЗГОТОВЛЕННЫЕ В ЛАБОРАТОРИЯХ
150-151
152-154
155-158
СИГНАЛЬНАЯ ИНФОРМАЦИЯ
АННОТАЦИИ СТАТЕЙ, НАМЕЧАЕМЫХ К ПУБЛИКАЦИИ В ЖУРНАЛЕ ПТЭ
159-164
ПРАВИЛА ПУБЛИКАЦИИ В ПТЭ
165-168