Instruments and Experimental Techniques最新文献

The paper concerns a pulsed power supply module of the electromagnet for a mobile gamma-ray generator based on a BIM-type (air-cored, pulsed, small-size) betatron. The module contains a pulsed power supply system of the betatron electromagnet and its transportation, operation and storage system. The first system includes a 0.7 MJ capacitive storage (a bank of eight capacitors of 300 μF and 24 kV each) and a switching unit. The second system includes a specially equipped twenty-foot cargo container on a semitrailer. The pulsed power supply system is used for producing a unipolar current pulse with the amplitude of 110 kA and the length of 1 ms at the base in the electromagnet windings. The time spread of the system triggering is less than 50 ns. The electric circuit diagram, the power supply system operation procedure together with the results of the module test runs are provided. The oscilloscope patterns of the signals from sensors for monitoring the parameters of the power supply system are presented. The module design can be applied in other mobile electrophysical facilities, taking into account their electric parameters.

The results of measuring the dark count rate and the probability of after-avalanche detection of a single-photon detector using avalanche photodiodes manufactured by Wooriro and RMY Electronics are presented. The operation of avalanche photodiodes was studied at temperatures down to −80°C. As a result, both diodes achieved dark count rates of a few hertz in the continuous operation with a quantum efficiency of 10%. It was experimentally demonstrated that an RMY Electronics diode provides a lower probability of after-avalanche operations compared to a Wooriro diode, all other conditions being equal.

A prototype of a laser engineering of microbial systems (LEMS) setup based on a 1.5 μm microchip laser is presented. The relevance of the development is determined by the need to create systems adapted for operation in microbiological laboratories. Experiments were conducted to study the features of the interaction of laser radiation with the Ti film of the donor substrate. An interesting effect of optical feedback formation that affects the stability of the process is shown, and a recommendation for its elimination is given. The results demonstrate the potential of using microchip lasers to create compact LEMS systems, which could facilitate wider adoption of this technology.

A detector with the a 40-cm-thick 40-cm-diameter scintillation module has been calibrated using cosmic rays. This detector is intended to detect neutrons in the future experiment at the S-25R Pakhra accelerator of the Lebedev Physical Institute with the aim of studying neutron−neutron scattering in the γd → π⁺nn reaction with a deuteron. It has been determined that when the mean energy deposited by cosmic muons in the module is 80 MeV, the energy resolution is δ = 7%, and the time resolution varies from 4 to 8 ns at distances between the trigger counters and the scintillation module ranging from 11 to 74 cm.

This article examines the calibration of the M.N. Pavlinsky ART-XC X-ray space telescope, which has been operating in space since 2019. This is the first X-ray mirror telescope in Russia. The novelty of this telescope required the development of new methods and equipment for its calibration. The methodology, procedure, and results of the telescope calibration and a test bench for this purpose are described. The results of processing the telescope observations of some astrophysical sources obtained on the basis of the performed calibration are presented.

The basic principles and methods for implementing X-ray near-field speckle imaging are presented. The applicability of the method for obtaining 2D and 3D images with absorption, phase, and dark-field contrast, as well as for the metrology of X-ray optics is considered.

This work is devoted to measuring the yields of iridium radioisotopes ¹⁸⁹Ir, ¹⁹⁰Ir, and ¹⁹²Ir and platinum radioisotopes ¹⁸⁸Pt, ¹⁸⁹Pt, and ¹⁹¹Pt upon irradiation of a thick target of natural metallic iridium with protons with energies of approximately 30 MeV at the U-150 cyclotron of the Kurchatov Institute. The experimental yields were compared with the corresponding calculated results obtained using data from the TENDL-2023 library. Based on the experimental results obtained in the work on the yield of the target radioisotope ¹⁸⁹Ir in the reaction ¹⁹¹Ir(p,3n)¹⁸⁹Pt(T_1/2 = 10.87 h) → ¹⁸⁹Ir and in the direct reaction ¹⁹¹Ir(p,p2n)¹⁸⁹Ir, a conclusion was made on the possibility of creating an ¹⁸⁹Ir/^189mOs isotope generator with an Auger and conversion electrons ^189mOs emitter activity at the level of 100 MBq, which will ensure its application in clinical practice.

This study presents a numerical investigation of a Hybrid Plasma–Semiconductor Trigger Switch (HPTS) combining a GaN-based driver with a low-pressure pseudo-spark discharge channel. The objective is to evaluate the potential of integrating deterministic semiconductor switching with high-current plasma conduction for pulsed-power applications. A dynamic simulation model was developed to capture the interaction between time-dependent plasma conductivity, GaN driver dynamics, and circuit parasitics. Simulated results indicate that the HPTS can achieve sub-nanosecond jitter (less than 0.5 ns), bidirectional current conduction up to ±17 kA, and current rise rates of 300–400 A/ns. Performance is shown to improve with lower discharge pressures and faster driver rise. Comparative analysis with reported experimental data for thyratron and pseudo-spark switches demonstrates that the simulated HPTS achieves faster switching, higher timing precision, and improved energy transfer efficiency (96–97%). These findings highlight the potential of HPTS architectures for high-speed pulsed-power systems, while clarifying that the reported results are derived from numerical simulations rather than physical experiments.

The design of a prospective electron spectrometer being developed for the Venera-D space mission and intended to measure the parameters of the electron distribution function in the orbit of an artificial satellite of Venus is described. The spectrometer can also be used for recording the parameters of cosmic plasma onboard other near-Earth and interplanetary spacecraft. The results of laboratory tests of a prototype spectrometer fabricated using additive technologies are presented. The instrument has an energy resolution of 6.5%, a field of view of 160° in the azimuthal angle and 6° in the polar angle, and an azimuthal angular resolution of up to 10°. The results obtained confirm the achievability of the stated characteristics of the instrument and demonstrate the applicability of additive technologies for prototyping plasma spectrometers.

The paper examines the parameters of plastic scintillation detectors with various systems for output and detection scintillation radiation, designed for detecting gamma rays over a wide energy range. Such detectors, having high light output, find broad application in nuclear physics, high-energy physics, and radiation monitoring systems. However, the detection, for instance, of low-energy gamma radiation with low light output of gamma rays requires low detection thresholds, which leads to an increase noise counts. The paper compares the efficiency of gamma detection by relatively large-sized detectors using vacuum photomultiplier tubes (PMTs) and silicon photomultipliers (SiPMs) as photodetectors. In the latter case, light is extracted from the scintillator using wavelength-shifting fibers. Detectors with such a scintillation-detection system surpass detectors with vacuum PMTs in a number of parameters. Nevertheless, the paper demonstrates that, in the low-energy gamma detection range, which is important for radiation-monitoring systems, detectors based on SiPMs and wavelength-shifting fibers, at an energy of 60 keV for example, are an order of magnitude less efficient in registration compared to detectors with vacuum PMTs. It is shown that this is due to a significant background of the SiPMs dark noise.