Finding the parameter of digital discrimination between scintillation responses to neutrons and photons in radioactive and fissile material detection systems

Use of a digital technique for discriminating between neutron and photon responses of high-efficiency scintillation detectors in fissile material detection systems is proposed. Software-controlled processing of scintillation signals makes it possible to separate the time and energy dependences of the neutron and photon responses of the detection system and obtain various physical parameters indicating the presence of fissile materials in the subject of inspection. Original Russian Text ? V.L. Romodanov, A.G. Belevitin, I.V. Mukhamad’yarov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 133–137.     

Broad beam source of fast atoms produced as a result of charge exchange collisions of ions accelerated between two plasmas

Experimental study of a fast argon atom beam source is carried out and the study results are presented. The source comprises a 90-mm deep and 210-mm in diameter hollow cathode as well as a flat emission grid, both electrodes made of titanium. The study revealed main factors, which influence the zone diameter of homogeneous substrate etching by a broad beam of fast argon atoms, produced as a result of charge exchange collisions of ions, accelerated between a plasma emitter inside the hollow cathode and a secondary plasma in the working vacuum chamber, the plasmas being separated from each other with the grid. It is shown that at a distance from the grid, exceeding the resonant charge exchange length up to 4 times, elastic collisions have no appreciable impact on the spatial distribution of the etching rate in the vacuum chamber. The homogeneous etching zone diameter is mainly influenced by angular characteristics of accelerated particles in the grid plane. At a constant beam power up to 3–5 kW the diameter is rising with a decrease of their energy and with a corresponding increase of the beam current. Original Russian Text ? S.N. Grigoriev, Yu.A. Melnik, A.S. Metel, V.V. Panin, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 4, pp. 166–172.     

A magnesium vapor charge-exchange target for an accelerator mass spectrometer

The target design and results of experiments aimed at stripping carbon ions in magnesium vapor are presented. It is proposed to substitute such a target for gas targets conventionally used in accelerator mass spectrometers, which will reduce the background ion charge exchange outside the target. Original Russian Text ? V.F. Klyuev, V.V. Parkhomchuk, S.A. Rastigeev, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 101–104.     

A laser ion-mobility spectrometer

The process of ion-packet broadening in a longitudinal laser spectrometer of ion mobility is studied. The contributions of the diffusion, Coulomb, and other broadening mechanisms are compared. The resolution of the developed spectrometer was measured (R ∼ 45) in atmospheres of both purified air and pure nitrogen. The dependence of the spectrometer resolution on the drift voltage was studied. The recorded spectra of a number of molecules of explosives with an extremely low pressure of saturated vapors indicate a high sensitivity of the developed spectrometer (no worse than 10⁻¹⁴ g/cm³). Original Russian Text ? G.E. Kotkovskii, I.L. Martynov, V.V. Novikova, A.A. Chistyakov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 110–116.     

A peaker on commercial high-power semiconductor diodes for exciting free magnetization oscillations

A unit intended for shaping pulses of the magnetic field that initiate free magnetization oscillations in magnetic films is described. The unit consists of a peaker on a semiconductor diode and a differentiating RC circuit. It produces pulses with an amplitude of up to 10 Oe, a rise time of ≤ 0.3 ns, and a total length of ≤ 1 ns. The unit was used for studying free oscillations (in a 0.6- to 1.2-GHz frequency band) in ferrite-garnet films with easy-plane-type anisotropy. Original Russian Text ? O.S. Kolotov, A.V. Matyunin, O.A. Mironets, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 148–150.     

Simulation of micrometeorites using an electrodynamical accelerator

Results of experiments with a multiparameter detector of high-speed dust particles are presented. This detector is composed of induction (a Faraday cup), ionization, and photoelectric sensors. It allows simulation of micrometeorites over wide ranges of masses and velocities by measuring secondary effects due to collisions of particles with a wall. Experiments aimed at detecting high-speed dust particles have been carried out using an electrodynamical accelerator with an effective accelerating voltage of ∼650 kV. Original Russian Text ? N.D. Semkin, K.E. Voronov, A.V. Piyakov, I.V. Piyakov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 4, pp. 159–165.     

Calibration of a thin-layer gas sensor

A method is proposed for measuring the concentration dependence of the thin-layer gas sensor sensitivity in a dynamic mode using only one certified gas-air sample with an impurity concentration corresponding to the upper limit of the concentration range for which the calibration is performed. A decrease in the total time of the measurement run is an advantage of the method. The response speed of the sensor for ethanol vapor in air on the basis of a thin tin dioxide (SnO₂) layer is investigated, and the concentration dependence of its sensitivity to ethanol vapor is presented. Original Russian Text ? V.V. Kisin, V.V. Simakov, A.S. Voroshilov, A.I. Grebennikov, O.V. Yakusheva, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 1, pp. 158–160.     

On quantitative determination of radon concentration by γ-ray spectrometry of aerosol filters

The problem of determining the ²²²Rn concentration in air from γ-ray spectra of radon progeny is solved using the aerosol filters method. The systematic error of the method due to incomplete collection of radon progeny is determined. It is shown that, when comparing the filter activity to the analytical calculation, the use of a 20-cm-diameter 20-cm-tall NaI(Tl) crystal and a 4−π geometry makes it possible to measure radon concentration with an accuracy of 20-30%. Original Russian Text ? A.Kh. Khokonov, M.B. Masaev, Yu.V. Savoiskii, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 1, pp. 142–144.     

Spectral instrumentation for monitoring atmospheric ozone at millimeter waves

A spectroradiometer operating in the 2-mm wavelength range for monitoring the ozonosphere from the Earth’s surface is described. Unique data on the vertical ozone distribution in layers of the stratosphere and mesosphere difficultly accessed by other techniques have been obtained with this instrument. The reliability of the results of measuring the vertical ozone distribution at millimeter waves is due to the high sensitivity of the spectroradiometer, its optimized characteristics, and highly efficient data-processing techniques. Original Russian Text ? S.V. Solomonov, A.N. Ignat’ev, E.P. Kropotkina, S.V. Logvinenko, A.N. Lukin, P.L. Nikiforov, S.B. Rozanov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 138–144.     

A low-voltage ionization chamber for the ITER

An ionization chamber with an operating supply voltage of 10 V has been designed for use at the ITER. The sensitivity of the chamber filled with air at atmospheric pressure is 100–200 times higher than the sensitivity of the chamber pumped down to a pressure of 10⁻³–10⁻⁴ Torr. It is shown that application of the supply voltage modulation technique allows the pickup noise to be substantially reduced; as a result, the amplifier can be located at a large (70–100 m) distance from the chamber. Results of the experiments aimed at testing this technique on the T-10 facility are described. Original Russian Text ? Yu.V. Gott, M.M. Stepanenko, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 117–121.     

Characteristics of the detecting equipment for the nanosecond tagged-neutron technology

Detecting equipment for the nanosecond tagged-neutron technology has been developed, and its characteristics have been studied. The principles of arrangement and operation of the readout electronics based on the selection of useful events according to specified criteria and data accumulation by a buffer-memory unit with subsequent transfer of data arrays to a remote computer for processing and visualization. The main selection criterion is the presence of signals from α- and γ detectors within the time gate and amplitude ranges in the absence of overlapped events. A prototype of a setup for testing the developed equipment was assembled and experimental studies of its characteristics were performed. The time resolution attained in the recording of α-γ coincidences is 1.0 ± 0.1 ns at an amplitude resolution of the γ detector of 3.6–3.8%. Original Russian Text ? K.A. Balygin, M.D. Karetnikov, A.I. Klimov, K.N. Kozlov, E.A. Meleshko, I.E. Ostashev, G.V. Yakovlev, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 122–132.     

Radiation characteristics of getter materials in the region of a phase transformation

The results of studies of the radiation characteristics of samples of titanium and alloys thereof in the region of their polymorphous transformation and the temperature dependence of the emissivity in the β phase are presented. The calorimetric method of electron heating in high vacuum was used. It is shown that changes in the integral hemispherical emissivity ɛ _th for titanium iodide and industrial-grade titanium related to the transformation of a hexagonal close-packed lattice into a body-centered cubic lattice have different characters. Original Russian Text ? B.A. Shur, V.E. Peletskii, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 1, pp. 162–167.     

An experimental system for investigating the characteristics of optical sensor materials

An experimental system for investigating the characteristics of optical sensor materials, in particular, materials based on modified fluorescent micro- and nanoparticles, is described. The system can be used to obtain multicomponent gas-vapor mixtures, measure fluorescence and reflection spectra, and record color images of sensor materials with a time resolution of a few milliseconds. Experimental data obtained when investigating the responses of sensor materials to analytes are presented. Original Russian Text ? A.A. Khlebunov, D.S. Ionov, P.V. Komarov, V.M. Aristarkhov, V.A. Sazhnikov, A.N. Petrov, M.V. Alfimov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 1, pp. 145–150.     

基于非对称夹持的压电旋转驱动器设计

设计了一种新型非对称夹持压电旋转驱动器。通过对称性电信号激励粘贴在基板上的压电晶片,使基板自由端带动质量块非对称地往复摆动,进而产生非对称的惯性驱动力,实现压电旋转驱动器的定向运动。研制了非对称压电惯性旋转驱动器样机,搭建了驱动器的测试系统,对驱动器步长、摩擦力矩、载荷特性等进行了测试。结果表明,驱动器在电压为15V、频率为10Hz、夹持差为3mm时,步长分辨率为1.82μrad,摩擦力矩为2.475N·mm条件下的最大输出载荷为0.122N。     

Torsional Wear Behavior of MC Nylon Composites Reinforced with GF: Effect of Angular Displacement

The torsional wear behavior of monomer cast nylon (MC nylon) composites reinforced with glass fiber was studied with a self-made torsional friction tester. The worn surface of MC nylon composites was investigated with a scanning electron microscope. The worn surface of the steel disk was observed with a 3-D profiler. The experimental results indicated that the shape of torque–angular displacement (T–θ) curves changed from elliptic shape to quasi-parallelogram with the angular displacement increased from 5° to 30°. The serious wear characterized with a deep groove occurred at the position of about 1.5–4 mm radius of contact zone on the steel surface. The mass of MC nylon samples increased after torsional wear test. The torsional contact area can be divided into three zones: (a) a central stick zone, (b) an intermediate mixed-slipping annulus, and (c) a peripheral sliding annulus. The most serious wear occurred in the intermediate annulus because of the higher contact stress and mixed slip regime. The main wear mechanism of MC nylon samples was adhesive wear and abrasive wear. Plastic deformation of asperities was the character in the central zone. Slight adhesive wear was the main wear mechanism in the peripheral annulus.     

Threshold erosion fracture in the case of oblique incidence

Absract  A model of erosion wear at threshold velocities of incidence of abrasive particles is advanced based on the classic theory of dynamic contact interactions and the structural-time fracture criterion. A formula for calculating the intensity of erosion damage is developed, assuming that erosive particles slip over the surface of the target material during contact. The dependences of erosion wear on the angle of incidence of particles of various sizes are plotted. Original Russian Text ? I.I. Argatov, N.N. Dmitriev, Yu.V. Petrov, V.I. Smirnov, 2009, published in Trenie i Iznos, 2009, Vol. 30, No. 3, pp. 245–253.     

The CMD-2 cryogenic magnetic detector

The CMD-2 cryogenic magnetic detector used in a set of experiments on the VEPP-2M electron-positron collider at energies as great as 1.4 GeV is described. The design of the detector subsystems and the algorithms for reconstructing tracks in the drift chamber and the CsI and BGO calorimeters are presented. The spatial and energy resolutions of the detector systems have been determined from analysis of experimental data. The design of the superconducting solenoid and the layout of its powering by means of a superconducting transformer are shown. The trigger system of the detector and the conditions for recording “charged” and “neutral” events on a magnetic tape are described. The procedure used to monitor the parameters of the detector systems during the experiment is presented. Original Russian Text ? E.V. Anashkin, V.M. Aul’chenko, R.R. Akhmetshin, V.Sh. Banzarov, L.M. Barkov, S.E. Baru, N.S. Bashtovoi, D.V. Bondarev, A.E. Bondar’, A.V. Bragin, N.I. Gabyshev, D.A. Gorbachev, A.A. Grebenyuk, D.N. Grigor’ev, D.A. Epifanov, I.V. Zhuravkov, V.G. Zavarzin, A.S. Zaitsev, S.G. Zverev, F.V. Ignatov, V.F. Kazanin, S.V. Karpov, G.M. Kolachev, P.P. Krokovnyi, A.S. Kuz’min, I.B. Logashenko, P.A. Lukin, K.Yu. Mikhailov, V.A. Monich, M.A. Nikulin, A.B. Nomerotskii, V.S. Okhapkin, S.G. Pivovarov, A.S. Popov, T.A. Purlats, S.I. Redin, N.I. Root, A.A. Ruban, N.M. Ryskulov, A.L. Sibidanov, V.A. Sidorov, A.N. Skrinskii, V.P. Smakhtin, I.G. Snopkov, E.P. Solodov, P.Yu. Stepanov, A.I. Sukhanov, V.M. Titov, V.E. Fedorenko, G.V. Fedotovich, B.I. Khazin, A.G. Shamov, Yu.M. Shatunov, B.A. Shvarts, B.N. Shuvalov, D.V. Chernyak, S.I. Eidel’man, Yu.V. Yudin, 2006, published in Pribory i Tekhnika Eksperimenta, 2006, No. 6, pp. 63–79.     

A single-stage method for synthesizing carbon nanosystems

Carbon nanosystems were produced by a one-step method of direct current magnetron deposition, which was performed in the vacuum chamber in inert gas atmosphere on specially prepared substrates (mica or Al) coated with a thin Au layer. Investigations of the ready-made samples with probe and electron microscopes have demonstrated that the formed carbon film contains nanosystems, namely, X- and Y-shaped nanotubes, radial nanotubes in the form of a “sea urchin,” and nanotubes with nanobuds. Original Russian Text ? S.V. Antonenko, O.S. Malinovskaya, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 3, pp. 132–134.     

The 5N neutral particle beamline of the U-70 accelerator (Institute for High Energy Physics)

The 5N neutral particle beamline at the U-70 accelerator (Institute for High Energy Physics), which has been designed to produce a high-intensity neutron beam with the highest possible energy, is described. The average neutron energy is ∼51 GeV, and the beam intensity is up to 10⁷ neutrons per spill. For several years, this beam has been used to investigate charmed particles and narrow baryon resonances in neutron-nucleus interactions and search for exotic multiquark states with the aid of the EXCHARM spectrometer. Original Russian Text A.N. Aleev, V.A. Arefiev, A.A. Aseev, Yu.G. Basha, V.P. Balandin, A.P. Bugorsky, T.S. Grigalashvili, B.N. Guskov, A.A. Zhuravlev, V.N. Zapolsky, A.I. Zinchenko, I.M. Ivanchenko, N.N. Karpenko, M.N. Kapishin, V.D. Kekelidze, D.A. Kirillov, I.G. Kosarev, N.A. Kuzmin, M.F. Likhachev, A.L. Ljubimov, D.T. Madigozhin, A.N. Maximov, N.A. Molokanova, A.N. Morozov, F.N. Novoskoltsev, Yu.K. Potrebenikov, Yu.P. Petukhov, V.E. Simonov, V.N. Spaskov, G.T. Tatishvili, P.Z. Hristov, I.P. Yudin (EXCHARM Collaboration), 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 3, pp. 5–12.     

NMR stabilization of the magnetic field by a III1-1 magnetic inductometer in the frequency modulation mode

As applied to the problem of stabilizing the magnetic field of the NMR relaxometer-diffusiometer by a III1-1 magnetic inductometer, we propose a simple method for changing the III1-1 magnetic inductometer to the frequency modulation mode to exclude the field modulation arising from modulating coils of the III1-1 sensor at the studied sample location. Original Russian Text ? A.V. Anisimov, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 4, pp. 177–178.