In scientific devices such as laser inertial confinement fusion that achieve extreme physical effects, the energy system needs to output pulsed currents with high peak values and high rise rates. With the expansion of a high current pulsed arc in the gas gap switch, a strong shock wave overpressure is produced, which affects the performance and safety of the switch. Based on the arc energy balance theory, the analytical expressions of the arc channel radius and the shock wave overpressure peak value are obtained. Simulation calculations with different current and switch parameters show that the peak shock wave overpressure decays rapidly in time and space. It is most related to the energy injection rate in the current rising phase, and is also affected by the total energy injection and initial gas density. The arc channel radius and shock wave overpressure peak under different arcing atmospheres is calculated and analyzed. The results show that when O₂ is mixed with He or Ar as the arcing atmosphere, the arc shock wave overpressure peak can be effectively reduced.

pulse power,shock wave overpressure,energy injection,arcing atmosphere