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Results of measurements of soft X-ray emission with photon energies of <1 keV under conditions of a plasma focus (PF) experiment are presented. The experiments were carried out at the world's largest PF device-the PF-3 Filippov-type facility ( I ⩽ 3 MA, T/4 ≈ 15-20 µs, W ⩽ 3 MJ). X-ray emission from both a discharge in pure neon and with a tungsten wire array placed on the axis of the discharge chamber was detected. The wire array imploded under the action of the electric current intercepted from the plasma current sheath of the PF discharge in neon. The measured soft X-ray powers from a conventional PF discharge in gas and a PF discharge in the presence of a wire array were compared for the first time. [ABSTRACT FROM AUTHOR]

The reduction of the noise level and vibrations of a modern electrical drive are very significant problems during its development. The methods for solving this problem in the context of traditional threephase electromechanical systems are rather well studied but, however, have exhausted themselves in many respects. One promising variant for designing alternating-current asynchronous and synchronous motor drives with enhanced vibronoise characteristics is constructing it based on an actuating motor with an increased number of phases. On the one hand, the reduction of the noise and vibrations via application of multiphase machines ( m > 3) is conditioned by a decrease in tangential forces caused by pulsations of the electromagnetic torque of the motor. This is connected with the fact that an increase in the number of phases of the stator winding causes the sparseness of the harmonic composition of the field in the air gap and the elimination of asynchronous harmonics from it with a relative increase in synchronous ones. On the other hand, an increase in the number of phases substantially expands the possibilities for noise level reduction because of a decrease in radial magnetic forces acting between the stator and the rotor and causing dynamic deformations of the stator ring. Techniques for optimization of vibronoise characteristics of the asynchronous and synchronous motor drives and realization of their control system structure are proposed. Results of investigations of multiphase electromechanical systems that show the efficiency of the proposed solutions are given. [ABSTRACT FROM AUTHOR]

A system for recording X-ray ion spectra by means of a spherical crystal with the subsequent transformation of the X-ray spectrum into an optical image recorded with the help of an optical streak camera is described. A computer code intended to recover the plasma parameters from the intensities of spectral lines of H- and He-like ions of some chemical elements ( z = 6-29) is developed. Results of experiments on the determination of the parameters of hot plasma formed during the implosion of nested aluminum wire arrays at the S-300 high-current generator are presented. [ABSTRACT FROM AUTHOR]

The dynamics of the hot component of the plasma of imploding multiwire arrays has been analyzed using the time behavior of the X-ray spectral lines of multicharge ions. The spectra of H- and He-like aluminum ions with nanosecond time resolution have been detected using electron-optical chronography in experiments on the implosion of multiwire arrays by mega-ampere currents. The simultaneous appearance of the resonance lines of H- and He-like ions implies that the hot plasma whose electron temperature is higher than 0.5 keV has existed on the axis before the implosion of the main mass of the liner. The further dynamics of the intensity of the lines is primarily attributed to an increase in the mass of the emitting plasma. [ABSTRACT FROM AUTHOR]

Results are presented from experimental studies of the parameters of an X-pinch-based neutron source made of 70- to 80-μm-diameter deuterated polyethylene fibers. At currents of up to 1.7 MA and a current rise time of ∼150 ns, hot plasma spots were observed in the fiber crossing region. The formation of hot spots was accompanied by the generation of short soft X-ray pulses with a duration of 2–4 ns, as well as by neutron emission. The neutron energy was measured using the time-of-flight technique in four directions, at 0°, 90°, 180°, and 270° with respect to the load axis. The mean energy of the neutrons emitted along the axis towards the anode and cathode was found to be 2.0 ± 0.2 and 2.6 ± 0.1 MeV, respectively, and that of neutrons emitted in two opposite directions along the radius, 2.5 ± 0.1 and 2.4 ± 0.1 MeV. The maximum neutron yield at a current amplitude of 1.6 MA was of 1010 neutrons per shot. [ABSTRACT FROM AUTHOR]

The variation of the refractive index in polymethylmethacrylate (PMMA) behind the front of a shock wave excited by a high-current electron beam is investigated. The values of refractive index in a pressure range of 2 and 4 GPa are determined from the deviation of the diagnostic laser beam. The results are compared with the available data for shock compression of PMMA. [ABSTRACT FROM AUTHOR]

On the S-300 installation at currents up to 2 MA with rise time 100 ns, the investigation of the formation process of high-temperature plasma in fast Z-pinch was carried out. The central part of the loads was made from agar-agar and represented a deuterated polyethylene cylinder with small density 50 and 75 mg/sm3 and 1–2 mm diameter. On the ICT images, obtained in optical and soft X-ray range of a spectrum with 3–5 ns exposition, it is visible that on the axis of the polyethylene cylinder at the current`s rise time a cord is formed and it is separated into bright formations. They were observed on a background of a luminous area which occupied the initial neck volume. On time-integrated pinhole pictures obtained in SXR range (E > 1–4 keV), hot points with minimal size of 50 microns were registered. From the chronograms results, obtained by means of the optical high-speed-streak camera mount along the neck axis with time resolution < 1 ns, it follows that luminous formations arise sequentially during the different time moments (in 10–30 ns). Occurrence of luminous formations was accompanied by X-ray radiation occurrence with energy E > 1 keV with short duration of 2–4 ns. Simultaneously with X-ray radiation neutrons with the maximal yield of 4.5×109 were registered. The average energy measured in 4 directions under angles with an axis of: 0○ (above the anode), 90○, 180○ (under the cathode) and 270○, were accordingly: 2.4±0.2, 2.5±0.1, 2.5±0.1, 2.5±0.1 MeV. [ABSTRACT FROM AUTHOR]

Results are presented from experimental studies of the dynamics and parameters of the plasma generated by megampere (up to 2.3 MA) currents flowing through X-pinches formed from crossed wires made of various materials. The experiments were performed with different numbers of wires and different wire diameters. The X-ray yield in neon-like molybdenum lines (in the 2.5- to 3-keV photon energy range) from a <20 μm hot spot was larger than 10 J, and the soft X-ray power emitted from this spot reached 120 GW. The hot-spot lifetime estimated by comparing the measured and calculated emission intensities and line profiles of helium-like Fe and Cr ions was ∼10 ps. Hard X-ray emission in the photon energy range ≥800 keV was also detected. [ABSTRACT FROM AUTHOR]

Results are presented from experimental studies of a section of a magnetically insulated transmission line (MITL) with a current density of up to 500 MA/cm2 and linear current density of up to 7 MA/cm (the parameters close to those in a fast-Z-pinch-driven fusion reactor projected at Sandia Laboratories). The experiments were performed in the S-300 facility (3 MA, 0.15 Ω, 100 ns). At high linear current densities, the surface of the ohmically heated MITL electrode can explode and a plasma layer can form near the electrode surface. As a result, the MITL can lose its transmission properties due to the shunting of the vacuum gap by the plasma produced. In this series of experiments, the dynamics of the electrode plasma and the dependence of the transmission properties of the MITL on the material and cleanness of the electrode surface were studied. It is shown experimentally that, when the current with a linear density of up to 7 MA/cm begins to flow along a model MITL, the input and output currents differ by less than 10% over a time interval of up to 230 ns for nickel electrodes and up to 350 ns for a line with a gold central electrode. No effect of the oil film present on the electrode surface on the loss of the transmission properties of the line was observed. It is also shown that electron losses insignificantly contribute to the total current balance. The experimental results are compared with calculations of the electrode explosion and the subsequent expansion of the plasma layer. A conclusion is made that the life-time of the model MITL satisfies the requirements imposed on the transmission lines intended for use in the projected thermonuclear reactor. [ABSTRACT FROM AUTHOR]

The article focuses on the technology improvment for hardfacing crane wheels. According to a study, the wear resistance of the crane wheels, hardfaced with the Np-18Kh2G2 wire in friction tests, is far better than the resistance of the wheels deposited with the Np-30KhGSA wire. It is stated that it is 10 times better than the resistance of the sorbitized 65G steel. It is mentioned that the wheels hardfaced with the Np 18Kh2G2 wire prevent cracks and do not cause greater wear of the rails.