Propagation of high-power microwave pulses in air-SF_6 mixtures at high pressure

Article type: Research Article

Authors: Zhao, Pengcheng^a | Liao, Cheng^{a; *} | Lin, Wenbin^a

Affiliations: [a] Institute of Electromagnetics, Southwest Jiaotong University, Chengdu, Sichuan, China

Correspondence: [*] Corresponding author: Cheng Liao, Institute of Electromagnetics, Southwest Jiaotong University, Chengdu 610031, Sichuan, China. E-mail: c.liao@swjtu.edu.cn

Abstract: Simulations of the interaction of high-power microwave (HPM) pulses with air-SF_6 mixtures at high pressure in the fluid model are presented, where various reaction sets of air and SF_6 are taken into account. Introducing a small amount of SF_6 in air can drastically increase the breakdown threshold. At a higher pressure or for a larger pulse width, the breakdown threshold increases more significantly as the percentage of SF_6 in the mixture increases. The amplitude of the transmitted pulse in the air breakdown decreases with time and its width is shortened. Due to the higher attachment frequencies in the air-SF_6 mixture and SF_6, the amplitude of the transmitted pulse keeps almost unchanged after it experiences a short-time attenuation, and the pulse width is not strongly influenced. Most of the energy loss of the transmitted pulse in the gas breakdown propagates in the opposite direction, and the rest of energy loss is due to electron heating. The accuracy of the fluid model is verified by experimental results.

Keywords: High-power microwave, propagation, gas breakdown, fluid model

DOI: 10.3233/JAE-131698

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 3, pp. 257-269, 2013