Effect of emission on subnanosecond breakdown in a gas diode at low pressure

5th International Congress on Energy Fluxes and Radiation Effects 2016

Baksht, E.K.^1 ; Belomyttsev, S.Ya.^1 ; Burachenko, A.G.^1,2 ; Grishkov, A.A.^1 ; Shklyaev, V.A.^1,3

Institute of High Current Electronics, Russian Academy of Sciences, 2/3 Akademichesky Ave., Tomsk

634055, Russia^1

Tomsk State University, 36 Lenin Ave., Tomsk

634050, Russia^2

Institute of High Technology Physics, National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk

634050, Russia^3

关键词: Diode voltage;    High dispersion;    Interelectrode gaps;    Nitrogen pressure;    Numerical research;    Runaway electron beams;    Subnanosecond breakdown;    Tubular cathodes;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/830/1/012014/pdf
DOI  :  10.1088/1742-6596/830/1/012014

来源: IOP

【 摘 要 】

The paper presents experimental and numerical research results on the operation of gas diode at low pressure. A high dispersion in the runaway electron beam current (from 20 to 100 A) with respect to the average one (∼50 A) is observed for a tubular cathode with a working edge radius of 30 μm, nitrogen pressure of 30 Torr, and an interelectrode gap of 6 mm. Numerical simulation data show that the low beam current (∼20 A) is due to the early electron emission from the cathode (at the stage of low-voltage prepulse), in which the runaway electron beam is formed from the boundary of plasma layer developing early in the breakdown. The high beam current (∼100 A) is due to the delayed electron emission from the cathode, which increases the diode voltage and the runaway electron beam current. In the latter case, the runaway electron beam is formed directly at the cathode.