Nanosecond volume discharge in air initiated by a picosecond runaway electron beam
M.I. Yalandinb aLebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation bInstitute of Electrophysics, Ural Branch of the Russian Academy of Sciences, ul. Amundsena 106, Ekaterinburg, 620016, Russian Federation
For the study of the discharge in atmospheric air, the voltage pulse with amplitude of 250 kV and duration of 1 ns was used. The discharge started with advent of the field emission current from the cathode field enhancer. Then, the beam of runaway electrons with amplitude of 0.5—1 A and duration of 10−11 s appeared. The interaction of this beam with the voltage pulse was investigated by reflectometry method. The discharge event was identified by the reflected pulse polarity change. If runaway electron beam appearance is delayed by the time Δt1, then polarity inversion is delayed by the time of Δt2=Δt1=200 ps. This is caused by small discharge formation time of 33 ps due to a large number of runaway electrons (of about 108) which initiate discharge. The time between beginning of the discharge and the voltage inversion beginning did not exceed 100 ps. Theoretical estimation of this process is carried out based on the idea of multielectron initiation of the discharge. It is shown that in the experiment we observe the nanosecond discharge with multielectron initiation which is created by runaway electrons of the discharge.
Keywords: voltage pulse, Field emission, field enhancer, runaway electrons, reflectogram, multi-electron initiation, discharge DOI:10.3367/UFNe.2018.06.038354 Citation: Mesyats G A, Yalandin M I "Nanosecond volume discharge in air initiated by a picosecond runaway electron beam" Phys. Usp., accepted
Received: 26th, April 2018, accepted: 6th, June 2018