[en] Parameters of the muon spectrometer of the tagged neutrinos facility constructed in IHEP for measuring momentum and sihn of muon charge produced in neutrino interactions are presented. Spectrometer is composed of eight magnetized disks 5 m in-diameter and 25 cm thick interleaved with coordinate planes. Each disk has a winding providing for magnetic field intensity within 1.5-1.9 T. Charged particle coordinates are determined by measuring drift time in drift tubes. 80/20% argon-methane mixture is a working gas. Total tube volume is 30 m³. Flowsheet of readout system and characteristics of drift tubes are presented. 7 figs

[en] A design of multisection liquid argon ionization chamber is described. It is intended for measurements of ranges and identification of stopped in its volume of protons of upto 150 MeV energy and pions of upto 60 MeV energy. In the chamber of about 31 volume 48 plane electrode 100 mm in diameter are positioned. Electrodes are prepared from copper foil 20 mm thick at intervals from 1.8 to 2.5 mm. On the basis of characteristics obtained from α-particles, γ-quanta and cosmic rays it is found that energy resolution in a separate section is determined mainly by electronics noises and is equal to 150 keV, the accuracy of determining the particle range could be as high as 100-400 mm

[en] A possibility of use detectors on the base of plastic streamer tubes for precise particle coordinate determination is tested. The method, based on determination of charge centroid, which is induced by external electrodes, provides the space resolution deltasub(x)=530 μm, and resolution of the method based on drift time measurement is 110 μm < deltasub(x) < 350 μm. The electron drift velocity measured in the argon-isobutane gas mixture with a high isobutane concentration (1Ar:3C₄H₁₀) was (41.8+-4.3)x10⁵ cm/s. Coordinate accuracy obtained in both cases is better than that required to muon spectrometers with magnetized iron. It permits to use plastic streamer tubes for particle trajectory determination in such installations

[en] A compact device of 24 preamplifiers intended for operation at low temperature (approximately 77 K) is described. Each preamplifier is placed on the 47x25 mm panel and has a gain of about 50. At the use of TiS-75 input transistor noises for 120 pF capacity are 5 keV for semiconductor detector and 90 keV for the liquid argon ionization chamber. The drift of all the device per day is not more than 1 channel

[en] The results of studying two methods for particle coordinate measurement by means of plastic streamer tubes: one of them persupposes measurement of the center of gravity of charge distribution on external electrodes, the other persupposes measurement of electron drift time. It is shown that plastic streamer tubes may be used to determine particle coordinates with the accuracy of 500 μm when measuring the center of gravity of the charge induced on external electrodes and with the accuracy of 100-350 μm when measuring time of electron drift to the anode of the tube

[en] The results are presented of the investigation of a cylindrical filament counter (the filament diameter being 10 μm) filled with condensed argon. It has been observed that the ionization mode of operation is characteristic of both solid and liquid argon. The increase of a part of pulses up to the amplitudes exceeding the ionization pulse amplitude by a factor of 100 has been observed for a solid argon counter. The contribution of these pulses to the total amplitude distribution depends on the experimental conditions and exposition time and does not exceed 30%

[en] The investigation results are reported of gas intensification and energy resolution for two cylindrical proportional counters (cathode diameters of 6 and 14 mm respectively) field with Ar and mixture of 90% Ar and 10% CH₄ under pressures of up to 100 atm. Gold-plated tungsten wires, diameters 10.4, 16.4 and 20.8 μm, and also wire coated with a fine glass layer, have been used as anodes. An analysis of the obtained results has shown the multiplication factor to sharply decrease with pressure increase. For example, for the counter with a large cathode (14 mm), the multiplication factor does not exceed 20 at 100 atm. The counter works much better when CH₄ is added. When the counter is filled with a mixture composed of 90% Ar and 10% CH₄, the gas amplification factor equals to 10⁴ under all pressures of up to 100 atm. The counter energy resolution increases with anode diameters and gas pressures growth. However, wide-range variations of the gas amplification factor do not affect the value of the counter energy resolution

[en] The results of the experiment on investigation of the ²⁴Mg projectile fragments interaction are presented. The experiment is done at 4.5 GeV/cxnucleon ²⁴Mg beam of the JINR synchrotron. The main part of the apparatus is the spectrometer assembled of 40 Cherenkov counters with 5 mm thick plexiglas radiators. Absorption functions in C₅H₈O₂ for the primary beam and secondary fragments with 6 <= Z <= 11 have been measured. The interaction mean free path of the projectile fragments and probabilities of its productions based on the analysis of approximately 10⁵ interactions are presented

[en] The investigation results are presented of the characteristics of a cylindrical proportional high-pressure counter (cathode and anode diameters are 6 mm and 20 μm respectively) filled with argon and argon-methane mixtures at low temperatures. The maximum attainable coefficient of proportional electron multiplication at temperature lowering and constant density of the filling gas has been found to decrease. The maximum gas density at which the proportional mode is retained corresponds to gas density at room temperature and pressure of about 200 atm

[en] Investigated has been the operation of a proportional counter (the cathod diameter is 6 mm, and anode diameter is 20 μm) filled with a mixture of argon and xenon. The gas pressure in the counter has varied in the range of 8-100 atm. Xenon addition results in noticeable shift of the amplitude curves towards lesser operating voltages as compared with pure argon and a mixtUre of argon and methane, with the maximum multiplication factor remaining adequately high. Presented are the spectra of the pulses of the gamma quanta from ²⁴¹Am with Esub(γ)=59.57 keV and gamma quanta of the K- line of copper with an energy of about 8 keV for pure argon and for mixture of Ar + 0.5% Xe at a pressure of 50 atm and room temperature. Investigations have revealed that resolution depends to a substantially lesser degree on the pressure than it has been found for pure argon and a mixture of argon and methane. The resolution has varied from 5 to 7% for 59.57 keV with the pressure varying from 8 to 100 atm. Increase in xenon concentration leads to line broadening. As the obtained results show, O.5% xenon addition to argon offers greater advantages over the use of methane as a quenching agent in the high-pressure proportional counters