[en] The book of abstracts contain various presentations in the field of plasma physics. Most of the presentations are theoretical

[en] Full Text:We report results on the optimization of the design of a high-current hollow anode electrical discharge electron beam source triggered by a ferroelectric surface discharge. For the ferroelectric sample we used a BaTi solid solution with a large dielectric constant epsilon =: 1600. Three different electric schemes for ignition and sustaining of the hollow anode discharge were investigated. The studied hollow anode designs allow reliable ignition and sustaining of the discharge with current amplitude of up to 1.2 kA and pulse duration of up to 20 Vs, with and without gas flooding. It was found that the rise time of the discharge current monotonically decreases from N 10 vs to N 7.5 vs with the increase of the background pressure from 4 Pa to 7 Pa. Generation of high-current electron beams was demonstrated under an accelerating voltage of up to 300 kV and N 400 ns pulse duration. It was shown that the use of an optimal resistor which supplies an auto-bias potential to the hollow-anode output grid eliminates almost entirely the plasma pre-filling of the accelerating gap prior to the application of the accelerating pulse. In addition, it was found that within a certain range of time delays (12.5 vμs - 15.5 vμs) of the application of the accelerating pulse with respect to the beginning of the hollow anode discharge, the amplitude of the diode current remains practically unchanged in spite of a considerable decrease in the amplitude of the discharge current

[en] Full Text:Underwater wire electrical discharges (OWED) generated by pulsed high-current nanosecond and microsecond generators can be considered as sources of non-ideal plasma. In our experiments with UWED we used microsecond (T1/4 = 2ns, Imax=100kA, dI/dt = 5 x 10¹⁰A/s, W=3.3 kJ) and nanosecond (T_1/4 = 60ns, Imax = 80kA, df/dt = 2 x 10¹²A/s, W = 0.6 kJ) generators. The parameters of the generated SW were obtained using different pressure gauges and shadow photography with fast frame and streak cameras. The discharge channel plasma parameters were obtained by the analysis of the evolution of the discharge channel and pressure waves generated in water combined with equation of state of wire material. Also, time resolved spectroscopic data of the discharge plasma light emission was obtained for determination of the discharge plasma parameters. An attempt to receive total energy balance was made. Performances of nanosecond and microsecond UIWED are compared

[en] Full Text:Experimental and magneto-hydro-dynamic simulation results of nanosecond time scale underwater electrical Al, Cu and W wires explosions are presented. A water forming line generator with current amplitude up to 100 kA was used. Maximal current rise rate and maximal Joule heating power achieved during wire explosions were 500 Ga/s and 6 GW, respectively. Extremely high energy deposition of up to 60 times the atomization enthalpy was registered comparing to the best reported result of energy deposition obtained in vacuum wire explosion of 20 times the atomization enthalpy. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. A 1D magneto-hydro-dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature. Material conductivity has been calculated to produce best correlation of the simulated and experimentally obtained voltage. It has been shown that conductivity may significantly vary as a function of energy deposition rate in nanosecond time scale underwater electrical wire explosions

[en] Full Text: Experimental and magneto-hydro-dynamic simulation results of micro- and nanosecond time scale underwater electrical Al, Cu and W wires explosions are presented. A capacitor bank with stored energy up to 6 kJ was used in microsecond time scale experiments and water forming line generator with current amplitude up to 100 k A and pulse duration of 100 ns were used in nanosecond time scale experiments. Extremely high energy deposition of up to 60 times the atomization enthalpy was registered in nanosecond time scale explosions. A discharge channel evolution and surface temperature were analyzed by streak shadow imaging and using fast photo-diode with a set of interference filters, respectively. Microsecond time scale electrical explosion of cylindrical wire array showed extremely high pressure of converging shock waves at the axis, up to 0.2 Mbar. A 1D and 2D magneto hydro- dynamic simulation demonstrated good agreement with such experimental parameters as discharge channel current, voltage, radius, and temperature