Instruments and Experimental Techniques最新文献

A kicker (a pulsed deflecting device) has been developed for deflecting an intense electron beam without introducing distortion from induced fields. The kicker characteristics have been measured, and the kicker has been tested with an intense electron beam. The developed device is used in a pulsed X-ray tomography system to direct segments of an electron beam into different transport lines.

In this paper, fiber-optic sensors of temperature based on planar AWG multiplexers/demultiplexers are discussed. The design of the distributed temperature and temperature drops sensor is described and its transformative characteristics are obtained.

The paper presents a review devoted to the sources of low-energy high-current electron beams produced in guns with resistively decoupled arc plasma sources built into an explosive-emission cathode, which are initiated by a dielectric-surface flashover. The principles and main regularities of the operation of such guns with planar–axial and coaxial geometries of the diode forming radially converging beams are considered. The results of studies on the plasma-anode formation by a high-current reflective discharge initiated by electrons, which are emitted from the cathode spots of arc plasma sources, are presented. In addition, the results on the production of beams with the increased pulse repetition rate and on the lifetime of the cathode assembly with arc plasma sources are presented.

An experimental cell design for studying the properties of anisotropic materials under the action of a magnetic field during deformation is described. The developed method has been tested by studying the properties of low-dimensional samples of anisotropic materials subjected to deformation. Single glass-coated bismuth wires as more suitable objects characterized by a large elastic strain range were selected for these studies. Dependencies of the resistance of bismuth wires on deformation in a transverse magnetic field have been measured by modifying the design of the bronze console of the insert, in which the wire is fixed. The proposed method has been used to reconstruct the Fermi surface topology in single glass-coated bismuth wires under uniaxial deformation by studying quantum oscillations of the perpendicular magnetoresistance for different orientations of the magnetic field relative to the crystallographic axes.

The method for particle energy fast spectrometry with a flat-parallel ionization chamber without a Frisch grid is described. The cathode signals must be digitized for further waveform analysis, which can get information on the particle energy dissipated in the working gas and the particle emission angle. This method could be helpful in the case of tiny or huge dimension of the ionization chamber when Frisch grid manufacturing is quite difficult or impossible.

New technologies have been developed for the production of superconductor–insulator–normal metal–insulator–superconductor (SINIS) structures made of Nb, NbN, and Al, which serve as sensitive elements for radiation receivers in the terahertz and subterahertz ranges. Two-stage fabrication technology by selective etching of niobium and modernized fabfication technology by dry selective etching and anodization of niobium with an additional sacrificial layer of SiO₂ made it possible to create structures with narrow absorbers made of normal metal with a width of less than 10 µm. The fabricated structures have characteristics close to those theoretically expected. The results of the work can be used for the development and fabrication of ultra-sensitive detectors for terahertz and subterahertz ranges with operating temperatures from 1.5 to 9.0 K using optical photolithography methods, which allows their use in more accessible cryogenic systems than He³–He⁴ dissolution cryostats, which are used in work with classical SINIS structures with operating temperatures in the range of 100–300 mK, where Al is a superconductor.

The results of the development of terahertz (THz) passive devices for various applications are presented. The main principles of the development and manufacturing technology and the technical characteristics of the developed devices are discussed. The possibilities of using passive THz devices in various systems are considered.

RED-100 is a two phase detector with liquid xenon as a target material designed to study coherent elastic neutrino nucleus scattering (CEνNS) of reactor antineutrino at Kalinin Nuclear Power Plant (KNPP). Signals from the coincidence of background several single ionization electrons (SE) are similar to signals from CEνNS events. This paper describes machine learning algorithms designed to suppress such a background.

Experimental results on determining the spatial resolution and contrast sensitivity of radiography using Bremsstrahlung from an improved compact SEA-2 betatron with a maximum Bremsstrahlung energy of 2.5 MeV are presented. The measurements were performed using an AGFA NDT D4 Pb VacuPac X-ray film and a Duplex IQI image quality indicator (model EN 462-5). The results obtained with magnification coefficients K = 2.3 and 3.3 of the Duplex IQI indicator images show resolutions of 0.16 and 0.2 mm of pairs of thin wires of the indicator. The effective horizontal size of the radiation focus (approximately 0.3 mm), as well as the vertical size of the radiation focus (approximately 2 mm), which is perpendicular to the plane of the electron orbit, is estimated.

The presented work reports the results of measuring the spatial distribution of proton and secondary particle fluxes at the Prometheus proton therapy facility of the Physico-technical Center, Lebedev Physical Institute, and gives a comparison with simulation results obtained using the Geant4 software package. Measurements conducted with a water phantom, as well as with a compact neutron detector based on a boron-enriched scintillator developed at the Budker Institute of Nuclear Physics, demonstrated good agreement between the observed neutron fluxes and the simulations. The simulation data suggest that the mechanism of enhanced biological effectiveness observed in several studies during proton irradiation with the use of boron-containing compounds is questionable, given the significantly lower contribution to the radiation dose from alpha particles compared to the dominant component caused by protons and other reaction products.