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Plasma Sci. Technol. ›› 2018, Vol. 20 ›› Issue (4): 045505.doi: 10.1088/2058-6272/aaa8d8

• Plasma Technology • Previous Articles     Next Articles

Experimental investigation on the development characteristics of initial electrons in a gas pressurized closing switch under DC voltage

Rongxiao ZHAI (翟戎骁), Mengtong QIU (邱孟通), Weixi LUO (罗维熙), Peitian CONG (丛培天), Tao HUANG (黄涛), Jiahui YIN (尹佳辉) and Tianyang ZHANG (张天洋)   

  

  1. Skate Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Xi’an 710024, People’s Republic of China
  • Received:2017-11-07 Published:2018-01-15
  • Supported by:

    This work is supported by the Foundation of State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (No. SKLIPR1601).

Abstract:

As one of the most important elements in linear transformer driver (LTD) based systems, the gas pressurized closing switches are required to operate with a very low prefire probability during the DC-charging process to ensure reliable operation and stable output of the whole pulsed power system. The most direct and effective way to control the prefire probability is to select a suitable working coefficient. The study of the development characteristics of the initially generated electrons is useful for optimizing the working coefficient and improving the prefire characteristic of the switches. In this paper an ultraviolet pulsed laser is used to generate initial electrons inside the gap volume. A current measuring system is used to measure the time-dependent current generated by the growth of the initial electrons so as to study the development characteristics of the electrons under different working coefficients. Experimental results show that the development characteristics of the initial electrons are influenced obviously by the working coefficient. With the increase of the working coefficient, the development degree of the electrons increases consequently. At the same times, there is a threshold of working coefficient which produces the effect of ionization on electrons. The range of the threshold has a slow growth but remains close to 65% with the gas pressure increase. When the working coefficient increases further, γ processes are starting to be generated inside the gap volume. In addition, an optimal working coefficient beneficial for improving the prefire characteristic is indicated and further tested.

Key words: gas switch, working coefficient, prefire, initial electron