A “self-triggered” arc initiation applied in vacuum arc thrusters

School of Electrical Engineering, Beijing Jiaotong University - 100044, Beijing, China

Received: 22 August 2018
Accepted: 20 December 2018

Abstract

The low-voltage vacuum arc initiation is of great importance for the optimization of vacuum arc thrusters (VATs). A low-voltage trigger method is proposed in this paper, which is called “self-triggered” arc initiation. This method uses a special surface flashover to generate the initial plasma and initiate the vacuum metal arc. A carbon fiber material is adopted as the trigger electrode due to its excellent field emission characteristics and it is arranged in series with a current-limiting resistance to avoid the damage caused by a heavy arc current. The experimental results show that this method is able to reduce the arc initiation voltage to several hundred volts, which is below 8% of the vacuum gap breakdown voltage. It has also been found that this trigger method is highly reliable and the trigger number of 10⁴ with a low-melting-point material (Pb) has been performed. In addition, this method is proved to have no effect on the plasma generation characteristics and the impulse bit of the VATs. Therefore, the “self-triggered” method is able to achieve the similar trigger effect with other trigger methods in VATs. It provides an alternative choice for the further optimization of VATs in terms of quality and volume.