Vol 62, No 1 (2019)

A proton injector based on electron cyclotron resonance is described. It can operate for a long time without the need to apply a high voltage to its power-supply equipment without providing a coolant. For a supplied microwave power of ~150 W, the extracted ion current in a continuous mode was 17 mA at an energy of 45 keV and a proton content of 68%. The proton-beam divergence was 0.4°, and the normalized rms emittance was ε = 0.13π mm mrad.

A new liquid scintillator detector created at the Carpet-2 air shower array of the Baksan Neutrino Observatory of the Institute for Nuclear Research is described. The detectors of this type will be placed in the modules of the ground-surface part of the new Carpet-3 array, which will be used to study galactic diffuse γ rays with energies of primary gamma rays E_γ > 100 TeV. For this detector the most probable amplitude of the anode signal from extensive air showers (EAS) is approximately 13 mV, while the energy resolution is ~42%. The inhomogeneity of the light-collection coefficient is 0.26. The number of photoelectrons at the photocathode is approximately 360. The detector is easy to operate and costs less than the traditional scintillation detectors used in our air-shower array.

The key characteristics of the functioning system for acquisition and storage of experimental data from the T-11M tokamak, as well as the reasons for its complete replacement, are presented. The requirements for the new system and the results of its development are described.

A low-cost two-channel correlation and autocorrelation counter has been developed for analyzing photon pulses from photomultiplier tubes. It includes a digital oscilloscope with the function of signal storage and transmission and a computer used to set the thresholds and to count pulses and their correlations. The time resolution determined by the oscilloscope is half of the shortest digitization time, i.e., 1 ns in our case. The counter may find application in nuclear physics and laser location. Short sonoluminescence pulses are investigated in our study.

The results of using a dynamic magnonic crystal, which is created by a surface acoustic wave (SAW) in the structure of a film of yttrium iron garnet on a gallium gadolinium garnet substrate, for the development of a tunable nonreciprocal microwave filter are presented. A filter prototype that operates in the range of 3600–4200 MHz at a magnetic bias field of 640 Oe was developed and its main characteristics were measured. At a SAW frequency of 41 MHz and a power of 30 mW, the rejection depth was 23 dB. A SAW-frequency change by 1 MHz shifted the rejection frequency by ~7 MHz. The inversion of the signal-propagation direction in the device resulted in a shift of the rejection frequency by the value of the SAW frequency. The possibilities of the further improvement of the parameters of this device are discussed.

A technique is described for correctly measuring the mean lifetime of negative ions produced by resonant capture of slow electrons by molecules in the course of investigations with a static MI-1201V mass spectrometer.

The setup is designed to produce spin-polarized hydrogen and deuterium molecules. Superconducting sextupole magnets with a magnetic induction of 3.4 T near the poles and a field gradient of 320 T/m were used for the spatial separation of molecules with different magnetic moments by spin filtration in an inhomogeneous magnetic field. The choice of the location of the polarized-molecule source elements is justified. Cryogenic pumps are used in the molecular-beam detection chamber in order to obtain an ultrahigh vacuum. At a nozzle temperature of 7 K, the measured flux of spin-polarized hydrogen molecules is 3 × 10¹² molecules/s. For deuterium, the measured flux is lower by more than seven times due to the small magnetic moments.

The results obtained in the study of the avalanche process of electron multiplication in a thick gas amplifier of a new design are presented. The main feature of the device is the separation of the upper and lower parts of the amplifier by a gas gap with the preservation of the polyimide film as an insulator on the inner surface of the hole electrodes. The width of this gap can vary in the range of 0.1–1.0 mm, depending on the electrode size. With this separation, the surface leakage currents are absent between the electrodes and the charge is not induced on the inner surface of the gas-discharge gap. Due to this solution, it is possible to minimize the probability of both surface and volume streamer phenomena that turn into a Geiger or spark discharge. As a result, a pulse amplitude of a few volts was measured across a load of 50 Ω in a gas mixture of Ar + 20% CO₂ when the detector was irradiated with a ⁹⁰Sr β source.

A compact low-background setup for measuring radioactive contaminants in various materials is described. Two combined scintillation detectors consisting of two crystals with various decay times are used in the setup. In its sensitivity, the setup ranks between portable radiation-monitoring devices, whose sensitivity is insufficient for some applications, and unique large high-sensitivity systems. It may be a prototype of setups for radiation monitoring of samples for a wide range of applications.

An instrument has been developed for measuring the force of affine interactions, in particular, in biological systems. The structure of the instrument is described. It includes a replaceable cartridge with a quartz resonator for analyzing various biosystems by measuring the signal of detachment of molecules from the resonator surface. The instrument is a sensor device with which it is possible to analyze various biological objects, including viruses and bacteria, as well as to carry out DNA identification. Software has been developed to automate the processing of results and the identification of objects. The instrument can be used to carry out express analysis in medical institutions and research laboratories.

The construction of a hermetic transport container for mounting alkaline metal samples in the vacuum chamber of an accelerator during online measurements of the deuterium diffusion coefficients in metals is described. A glass capsule containing an alkaline metal sample is unsealed in a special box with an inert gas atmosphere and the sample is placed in a cylindrical hollow at the surface of a flat metal plate of the container. After this, the hermetic transport container with the sample is fixed in place on a stationary holder inside the accelerator chamber and is unsealed after a high vacuum is attained in the chamber. Sodium samples are assessed using the nuclear reaction analysis. It is shown that the sodium purity in oxygen, carbon, and other low-Z elements meets the requirements of the accelerator technique.

An original design for an electrochemical chamber and the construction of a high-voltage AC generator for electrochemical etching (ECE) of nuclear tracks in CR-39 polycarbonates sheets are presented. The electrochemical chamber was designed and manufactured in an engineering plastic in a vertical machining center. The high-voltage AC generator was built by using different electronic circuits: a signal oscillator, a preamplifier, a power amplifier, two power supplies and a voltage converter transformer. The experimental tests showed that the design of the electrochemical chamber allowed that ECE be developed efficiently, achieving a dielectric breakdown in the polycarbonate, and the generator supplied the electric current in a stable manner and with an excellent performance throughout the ECE. The conditions of chemical etching and electrochemical etching, as well as the electrical treeing generated in the CR-39 are also presented.

The design of a laboratory setup for the dry aerosol deposition of ceramic coatings using powders with various granulometric and phase compositions is described. Data on the formation of TiO₂ coatings from spherical rutile particles with a characteristic size of 20–50 μm are presented. It is shown that uniform heating of rutile particles in a gas–powder mixture to 600°C promotes the activation of their destruction and the increase in the efficiency of formation of nanostructured ceramic coatings with the initial phase composition.

A method for measuring local flame temperatures using a spectral-ratio pyrometer and a tomographic system based on this method are described. The theoretical substantiation of the proposed measurement method is given. A block diagram of the system containing four measuring mirrors and one multiplexing mirror is shown. The results of the computer simulation are presented, with which it is possible to estimate the error of the system depending on the number of mirrors used in it. The software developed for carrying out measurements with the maximum degree of automation under the test-bench conditions is described. The results of an experimental study using the tomographic system for measuring the field of local flame temperatures of a gas burner (in the range of 1500–2300 K) are presented. The results demonstrate the operability of the developed system.

A pulsed thermal calibration device has been designed to calibrate nonstationary heat flux sensors that are fixed in place on models for studying heat transfer in wind tunnels. The deep upgrading of the device has significantly expanded the range of its operating parameters: the heat-flow density increased from 0.01 to 50 W/cm² and the flow temperature increased to 550°C. Operation of the device became easier and the restrictions on the sizes of the calibrated models were removed. The experimental results obtained in the measurements for a device equipped with a flexible electric heater are also presented.