Vol 62, No 5 (2019)

The concept of a cascade gas target with krypton isotopes for medical ⁸²Sr radioisotope production is described. Using this concept, an experimental setup was created at the U-150 cyclotron of the Kurchatov Institute NRC for ⁸²Sr production with an ⁸²Sr yield of approximately 53 μCi/μA h using the ⁸⁰Kr(⁴He, 2n)⁸²Sr reaction in the ⁸⁰Kr target module. Descriptions of the system and its operation are presented. The setup performed well with reproducible results. It is noted that the ⁸²Sr radioisotope produced using the setup is free from an admixture of the ⁸⁵Sr radioisotope that is responsible for approximately one-half the irradiation dose to workers using standard ⁸²Sr–⁸²Rb isotope generators.

The issues of determining the momentum of charged particles at the focusing double-arm spectrometer (FODS) are discussed. The coordinate detectors are located at the exit from the analyzing magnet, while a profilometer of the center of gravity of the beam at the target during an accelerator cycle is at its entrance. ANSIS finite-element analysis software is used to obtain a regular grid of magnetic field vector values measured by the Hall sensor in a part of the magnet. The charged-particle momentum is determined based on the algorithm of decision tables with a polynomial approximation. Tables are produced by the Monte Carlo method by reconstructing the motion of a particle with a prescribed momentum in the magnetic field. The accuracies in determining the particle momentum and the particle production angles while accounting for the contributions from multiple scattering, measurement errors, and approximation uncertainties are presented. The distribution of the reconstructed trajectories in the target and the momentum spectrum of particles are shown.

A digital spectrum analyzer based on the fast Fourier transform of noise signals with bands up to 1024 MHz was designed to equip the RT-32 and RT-13 radio telescopes. The analyzer provides radiometric measurements in the continuum under exposure to radio interference, as well as the registration of radio emissions in spectral lines with high (up to 488 Hz) resolution in frequency. The article describes an analyzer with a spectrum computing device on five field programmable gate arrays (FPGAs) of the Virtex-4 series. The parameters and test results of the analyzer are given. Information is given about the development of a single-chip spectrum computing device based on the Virtex-7 with 8 times higher resolution.

A high-voltage power supply for a microfocus X-ray tube with the output-voltage adjustment range of 30–80 kV at a power of 20–240 W (the X-ray tube emission current is up to 3 mA) was developed. The source is based on a resonant voltage converter that provides switching of power switches at a zero voltage or a zero current. The source uses a method for controlling the output voltage by changing the supply voltage of the resonant-converter power stage. The use of the Silagerm-2106 modern organosilicon compound for high-voltage insulation of the circuit elements made it possible to additionally reduce the size of the circuit and place it together with the tube-cathode power supply and the module of communication with a PC in a standard 19-inch housing; the mass of the device is 21 kg.

A model of a gas-dynamic interface with a high-vacuum ion-pulling system has been developed. The main part of the ion source is the ERIAD electrospray with in-source atomization (ion extraction from solution elements at atmospheric pressure), owing to which it is possible to measure concentrations of elements that are capable of being cations in a solution. The interface is constructed according to the Kontrovitsa–Gray type with a slight misalignment of the inlet and outlet. From the gas-dynamic point of view, the interface is “long,” since its length is several times longer than the resulting “Mach barrel.” Tests have shown that the interface circuit allows application of a voltage as high as 800 V between the nozzle and the skimmer, thus providing atomization of elements of not only the first, but also the second group of elements of the periodic system. The developed interface model can be used as a prototype for upgrading dual-focusing mass spectrometers for future elemental measurements.

This paper describes a fluence sensor made on the basis of IS-7 dozimetric glass. Using such sensors, the fluence and the diagrams of directivity of flows of fast electrons at the LOOCH and ISKRA-5 facilities have been measured. It has been revealed that the electron flow at the ISKRA-5 facility is more narrowly focused and that the presence of background plasma with an electron concentration of n_e ∼ 10⁹ cm^–3 near the target leads to an increase in the maximum fluence of fast electrons by approximately an order of magnitude.

The Active spectroscopy plasma diagnostics (CXRS, charge eXchange recombination spectroscopy) and plans for its use in the ITER tokamak are described. A technique for the wavelength calibration of a multichannel polychromator spectrometer using a Fabry–Perot etalon is presented. This idea of the wavelength calibration of the spectrometer was originally used for the CXRS diagnostics in the JET tokamak. Using this technique, a high-resolution tri-band polychromator spectrometer, which was created for the CXRS diagnostics at the ITER facility, was calibrated. This polychromator spectrometer allows simultaneous measurements in three spectral ranges: 469–477, 529–538, and 650–661 nm. The obtained error of the calibration for various wavelengths was evaluated, which was on average 0.003 nm. The resulting calibration accuracy for different wavelengths is enough to meet the requirements for the CXRS diagnostics in the ITER tokamak with a margin.

The PIPLS-B ion energy mass analyzer is described for measuring and studying the ion and charge composition of the solar wind and its sources in the solar corona in the framework of the Interheliozond project. The main advantages of the device are the simultaneous registration of the mass composition of ions of selected energy, high energy resolution ΔE/E = 5%, and mass resolution M/ΔM = 60, a wide energy range from 1 to 20 keV, as well as its relatively small size and weight. A computer simulation of the electron-optical circuit of the device was carried out; the original detector assembly of the device was manufactured and tested.

An infrasonic hydrophone has been developed based on the pyroelectric technology. The hydrophone sensor is a thin plate (a pyroelectric element) surrounded by air. Variations in the pressure in air are followed by temperature variations that are perceived by the pyroelectric element.

A simple digital spectral absorption meter for optical radiation from liquids designed for operation in the field is described. High measurement stability and linearity of the transfer characteristic were achieved through the use of a modification of the zero-measurement method. The maximum value of the nonlinearity of the transfer characteristic of the meter for the full measurement range did not exceed three to four low bits of the 10-digit digital code.

The possibility of controlling the curvature of the profiles of the surface of X-ray optical elements using single-crystal SiO₂(011) plates of rectangular and trapezoidal shapes was studied. In bending regulators (BRs) of various forms, the active element was a piezoelectric bimorph glued to a single-crystal plate. Experimental and calculated data of changes in the profile and radius of curvature of the surface of the used plate are given. The influence of the forms of the components of the bending regulator is shown on the initial profile and surface curvature of X-ray optical elements.

An installation for compressing inert gases to pressures of tens of kilobars is described. The installation differs from its analogs described in the literature in the method for supplying compressed gas into the chamber and in the use of O-rings as a basis for movable and fixed seals.

The lower eigenfrequency of a piezoelectric accelerometer in fixed and unfixed states was determined by carrying out mounted resonance testing (MRT) of a NEXUS 2692 amplifier. The MRT was complemented by spectral analysis of the piezoelectric-accelerometer response to an electric pulse, which was performed using the fast Fourier transform method. Based on the lower eigenfrequency of the fixed piezoelectric accelerometer determined thereby, it was possible to confirm the quality of sensor fixing on the test object and evaluate the reliability of results obtained after loading.