Parameters of runaway electron beam generated during excitation by nanosecond voltage pulses in short gaps filled with nitrogen

Parameters of a supershort avalanche electron beam (SAEB) in nitrogen excited by the triangular-shaped voltage pulses with 45kV amplitude in incident wave and full width at half-maximum (FWHM) of ~ 1 ns were investigated. In experiments, cylindrical-shaped cathodes made of aluminum and stainless steel were used. An interelectrode distance in the gas-filled diode was 3, 5, and 8 mm. It was established that the highest values of SAEB's current were registered with an aluminum cathode. It was shown that, in contrast to the case of 8-mm gap length, when the interelectrode distances were 3 and 5 mm, the amplitude of SAEB current pulse in nitrogen began to decrease with high values of the pressure – 100 and 50 kPa, respectively