Journal of Radio Electronics. eISSN 1684-1719. 2025. ¹11
Full text in Russian (pdf)
DOI: https://doi.org/10.30898/1684-1719.2025.11.22
17th International Conference
Gas Discharge Plasmas and Their Applications
Ekaterinburg, Russia, 8-12 September 2025
Kinetics of the radial runaway electron flow
in a transversal magnetic field
N.M. Zubarev 1,2, Yu.I. Mamontov 1, M.I. Yalandin 1,2
1Institute of Electrophysics UB RAS
620016, 106 Amundsena Str., Ekaterinburg, Russia
2Ð.N. Lebedev Physical Institute RAS
119991, GSP-1, 53 Leninskiy Ave., Moscow, Russia
The paper was received October 2, 2025.
Abstract. The work is devoted to a numerical study of runaway electron kinetics in atmospheric pressure nitrogen at the initial stage of radial breakdown in a coaxial transmission line with a wave impedance of 45 Ohm. The study was performed within the framework of the axisymmetric 2D-3V (two coordinates and three velocity components) Monte Carlo model. The problem statement considered the presence of a 0.3‑mm‑thickness disk-shaped electric field enhancer located at the inner conductor of the coaxial line. The enhancer protruded above the inner conductor of the line by 2.5 mm. The space area near the enhancer was considered to be a source of runaway electrons. In addition, the presence of a strong axial homogeneous magnetic field near the amplifier was taken into account. The magnetic field induction varied from 0.15 T to 2 T. The voltage between the line conductors was set in the range of 100-150 kV. Within the simulation, the motion of fast electrons in the coaxial gap was considered, taking into account their scattering on gas molecules and interaction with homogeneous magnetic and inhomogeneous electric fields. It was shown that, within the system under consideration, runaway electrons never reached the anode, i.e. the outer conductor of the coaxial line, if the magnetic field induction was greater than ~0.25 T. In turn, if the magnetic field induction was >0.5 T, the runaway electron radial drift was suppressed at all; however, there was an axial drift with a velocity of ~8 mm per 100 ps. Based on the simulation results, a qualitative description of three scenarios of the dielectric strength violation in magnetically insulated air-filled coaxial lines was proposed. The obtained results explain the results of recent experiments on the study of the coaxial air-filled duct breakdown.
Key words: coaxial transmission line, subnanosecond breakdown, runaway electrons, Monte Carlo technique.
Financing: The research was carried out with financial support of the Russian Science Foundation under grant number 23-19-00053, https://rscf.ru/project/23-19- 00053/.
Corresponding author: Mamontov Yuriy Igorevich, mamontov@iep.uran.ru
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For citation:
Zubarev N.M., Mamontov Yu.I., Yalandin M.I. Kinetics of the radial runaway electron flow in a transversal magnetic field. // Journal of Radio Electronics. – 2025. – ¹. 11. https://doi.org/10.30898/1684-1719.2025.11.22 (In Russian)