Study on Multichannel Discharge Characteristics of Multigap Gas Switch Gaps

Multigap gas spark switches are commonly utilized in linear transformer drivers (LTDs) because of their outstanding static and triggering performance. The number of discharge channels in the switch gap has an effect on the inductance and dissipated energy of the switches. To explore the multichannel discharge characteristics of the switch gaps, a two-gap gas switch (TGGS) with one trigger gap and one self-breakdown gap is designed. The trigger experiments are conducted on the TGGS under various switch working coefficients and nanosecond trigger pulses with different rise rates. The number of discharge channels in the switch gap is recorded by a intensified charge-coupled device (ICCD) camera. The frequency distribution of the number of discharge channels in the trigger gap and the self-breakdown gap is shown under different operating conditions. The experimental results indicate that the number of discharge channels in the self-breakdown gap is significantly more than that in the trigger gap. The preionization obviously increases the number of discharge channels in the trigger gap. The influence of the number of discharge channels in the switch ON the discharge loop current is discussed, and the inductance and dissipated energy of spark channels in the switch gap under different trigger settings are calculated. Increasing the trigger voltage rise rate, the working coefficient, or introducing preionization can correspondingly promote the number of discharge channels in the switch gap, which reduces the inductance and dissipated energy of the switch and thus improves the rise rate and amplitude of the brick current.