Vol 59, No 2 (2016)

The purpose of this review is to give experts, who use electronic techniques in experiments or measurements in applied areas, whenever it is possible, a complete picture of the past five-year rapid development of application specific integrated circuits for readouts and processing of signals from up-to-date detectors of nuclear particles. Due to the large information content, the review is formally divided into two parts. The use of the application specific integrated circuits in different experimental or measuring plants is considered in this second part. Both parts have the common classification table, numbering of cited papers, drawings, and formulas.

Extraction and collimation of the 50-GeV proton beam with a bent silicon crystal at the U-70 accelerator of the Institute for High Energy Physics (Protvino, Russia) was investigated. Until recently, proton beam extraction (and collimation) from accelerators has been effected using crystals with the (111) or (110) plane orientation, when the beam propagates far from the crystal axes. In the described experiment, the silicon crystal was oriented so that the proton beam was incident on it near the 〈110〉 axis. Under these conditions, a part of the beam was deflected by the crystal owing to the dynamic chaos phenomenon. The maximum beam extraction efficiency was as high as ~80%.

The LE-73 and LE-78 modules of MISS system designed for readout and recording of signals from multiwire chambers and hodoscopes are described. The use of an Altera FPGA provides a means for producing different modifications of the modules and adapting their operation to specific requirements of experimental setups. Owing to the availability of a high-speed internal memory, it is possible to design time-to-digital converters with a “common stop” and a 5-ns step and to store data in an internal FIFO memory.

The results of experimental studies of the process of switching a composite semiconductor switch, which consists of series-connected insulated-gate bipolar transistors with artificially nonuniformly distributed operating parameters are presented.

A pulsed-power high-voltage generator, which is combined with an electric-discharge chamber, is designed for selective disintegration of quartz raw minerals and other nonconductive natural and artificial materials. The main parameters of the generator are as follows: the voltage-pulse amplitude, up to 500 kV; the discharge-current amplitude, up to 30 kA; the duration of current pulses (the half-period an oscillatory discharge), 70–90 ns; and the pulse repetition rate, up to 50 Hz. The generator is characterized by a high efficiency, a long service life, the possibility of long continuous operation, and the fulfillment of the electromagnetic compatibility requirements. The experience of the operation of three constructed installations testifies to their high reliability: the number of accumulated pulses in a typical mode (450 kV, 20 Hz) exceeded 108 pulses without a repair or replacement of units.

The circuit of a power source for charging a capacitive storage is described. It is based on the formation of a stepwise-decreasing current via switching of identical rectifying modules from the parallel connection to the series connection, as the storage is being charged. The comparative simulation results and experimental data are presented for the system with four output channels, which form one-, two-, or threestep current of the capacitive storage depending on the control algorithm. It is shown that the charging-cycle duration shortens with the current remaining at a constant level in most of the circuit elements.

A method for measuring the mechanical recoil impulse of a target produced by the relativistic electron beam of the Calamary accelerator is described. A detector based on a piezoelectric sensor is used in measurements. Results of measurements are presented for the mechanical recoil impulse produced by the relativistic electron beam with an energy as high as 300 keV, a current of up to 30 kA, and a duration of ~100 ns that is incident on an epoxy target. The energy flux density on the target surface is varied in the range of 1–10 GW/cm². The maximum measured impulse value is 0.32 N · s at an energy flux density of 10 GW/cm² (an energy fluence of 810 J/cm2).

The effect of the potential difference at the focusing chamber electrodes of XP2020, FEU-85, FEU-87, and FEU-93 photomultiplier tubes on the intensity of afterpulses resulting from gas discharge processes is investigated. The time distributions of afterpulses in H6780 and R7600U-200 metal channel photomultiplier tubes are also analyzed.

A technique for obtaining gas sensor samples from graphite paper with a nanotube film is described. Current-induced annealing of the graphite paper and additional evaporation of a nanotube graphite film in a hydrogen atmosphere are combined in the developed technique. The current−voltage characteristics of the samples have been measured at room temperature in air, in vacuum, and at low concentrations of NH₃, ethanol, and acetone. Experiments demonstrate that these samples containing carbon multiwall nanotubes can be used as a gas sensor to detect the presence of NH₃ and acetone. They are characterized by high sensitivity and selectivity, fast response, restoration, and stability of the characteristics. The estimated sensor sensitivities to NH₃, acetone, and ethanol at a current of 96.8 mA are ~15, ~12, and ~1 mV/Torr, respectively. Their sensitivity is determined by the difference in the behavior of their current−voltage characteristics under exposure to NH₃, ethanol, and acetone. The sensor features fast response (5–20 s) and restoration (within 5 min, restoration to the initial state before the exposure to NH₃ is 100.2%), as well as the stability of its characteristics (the pressure ranges from 1 × 10^–6 to 760 Torr).

For typical cross-shaped specimens subjected to simultaneous biaxial tensile loads, the specimens’ central section would elongate along different directions under plane stress condition. Consequently, the width of the specimens’ gauge length section would gradually decrease along the tensile direction, and true stress, which is based on the instantaneous width, is different from the values obtained from uniaxial tensile tests. To calculate the true stress of cross-shaped specimens, a horizontal biaxial tensile device was developed to apply the equi-biaxial loads. An optical observation method was adopted to measure the specimen’s true deformation. Then, an exponential fitting method was proposed on basis of the true deformation to describe the nonlinear deformation trajectory of the specimen’s gauge length section. Based on a theoretical model, the calculation method of the true stress was established, and the relationships between the true and engineering stress-strain curves were also discussed.

An electrochemical cell has been developed for determining the thermodynamical activity of a component in a solid solution (alloy) depending on its concentration at a temperature of up to 150°С and atmospheric pressure. A salt solution of glycerin is used as an electrolyte. Measurements can be simultaneously performed on 10–15 different samples in the cell under identical conditions for all compositions of the solid solution studied. This is ensured by using an inert electrode being displaced from sample to sample. In this case, the comparison electrode is common and immobile, thus substantially increasing the accuracy and reliability of experimental results, since this allows one to perform repeated (check) measurements of the EMF at a constant temperature on any sample with a specified composition.

An apparatus for thermodiffusion synthesis of multicomponent semiconductor compounds is described. CuInSe₂ polycrystalline films were obtained in the selenization temperature range 300°C ≤ Т_sel ≤ 400°C. The chemical analysis showed that the composition of the films that were synthesized at a selenization temperature of Т_sel = 400°C is stoichiometric. A series of diffraction lines that is characteristic of the chalcopyrite structure is present in the line X-ray diffraction patterns of these films.

Self-supporting ultralow density laser targets with an apparent density as low as 1 mg/cm³, a porous layer thickness of 60–500 μm, and a window diameter of 2.5 mm were prepared by thermally induced gelation of cellulose acetate solution in a mixture solvent between two glass slides using the mold casting method. In view of the low mechanical gel strength at a concentration of <0.2 wt %, supercritical drying of molded targets is carried out without separating the glass slides. For the target output to be radically increased, a new procedure has been developed based on rapid freezing of the solution on a metal brick from room temperature to–60°C and lower, down to–190°C, without initial gelation.