Energy Density Increasing in the Channel of Super-High Pressure Megaampere Discharge due to Resonance of Different Type Oscillations of the Channel

Discharges in hydrogen, ignited by wire explosion, with current amplitude up to 1.5 MA were investigated. Channel diameter oscillations were observed on the photostreaks. Voltage and current curves correlated with the photostreaks. At initial gas pressure of 5-35 MPa the oscillation period was proportional to square root of atomic number of the initiating wire material. These oscillations were associated with aligned magnetic and gas-kinetic pressures. At initial pressure of 80-160 MPa acoustic pressure fluctuations on the discharge chamber wall were increased up to 150 MPa and there were the growth of voltage fluctuations on the discharge gap up to 3 kV simultaneously with it. In some experiments it was observed abrupt increase in the oscillation amplitude, which can be caused by the resonance of the acoustic oscillations in discharge chamber volume and the oscillations connected with alignment of the gaskinetic pressure and the magnetic pressure, as far as frequencies of these oscillations are close to each other in accordance with the estimates and the experimental data. Resonance of different type oscillations can produce energy density increasing in the discharge channel. Thus, the appropriate initial conditions in the experiment allow to increase the energy density in the discharge channel. Keywords—High-current gas discharges, high pressure hydrogen, discharge channel oscillations. M. E. Pinchuk is with the Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (corresponding author to provide phone: 303-555-5555; fax: 007-571-5056; email: [email protected]). Ph. G. Rutberg, is head of with Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (e-mail: [email protected]). A. V. Budin is with the Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (e-mail: [email protected]). A. A. Bogomaz is with the Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (e-mail: [email protected]). A. G. Leks is with the Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (e-mail: [email protected]). S. Yu. Losev is with the Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (e-mail: [email protected]). A. A. Pozubenkov is with the Institute for Electrophysics and Electric Power of Russian Academy of Sciences, St.-Petersburg, Russian Federation (e-mail: [email protected]).