A voltage pulse with an amplitude of 250 kV and duration of 1ns was used to study discharge in atmospheric air. The discharge commences with emergence of a field emission current from the cathode field enhancer. Next, a beam of runaway electrons with an amplitude of 0.5—1 A and duration $10^{-11}$ s appears. Interaction between the beam and the voltage pulse was investigated using the reflectometry method. The discharge event was identified by the reversal of reflected pulse polarity. If the emergence of the runaway electron beam is delayed by a time interval of $\Delta t_1$, polarity inversion is delayed by the time of $\Delta t_2=\Delta t_1=200$ ps. This is due to the small discharge formation time, 33 ps, as a result of the large number of runaway electrons (about $10^8$) that initiate the discharge. The time interval between the beginning of the discharge and that of the voltage inversion is no longer than 100 ps. This process is theoretically estimated based on the concept of the multielectron initiation of the discharge. It is shown that observed in the experiment is the nanosecond multielectron-initiation discharge produced by the runaway electrons of the discharge itself.

Keywords: voltage pulse, field emission, field enhancer, runaway electrons, reflectogram, multi-electron initiation, discharge PACS: 51.50.+v DOI: 10.3367/UFNe.2018.06.038354 URL: https://ufn.ru/en/articles/2019/7/f/ 000492057500006 Citation: Mesyats G A, Yalandin M I "Nanosecond volume discharge in air initiated by a picosecond runaway electron beam" Phys. Usp. 62 699–703 (2019) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 26th, April 2018, accepted: 6th, June 2018 Оригинал: Месяц Г А, Яландин М И «Наносекундный объёмный разряд в воздухе, инициируемый пикосекундным пучком убегающих электронов» УФН 189 747–751 (2019); DOI: 10.3367/UFNr.2018.06.038354