Study on Pseudospark Switch Triggered by 532-nm Focused Laser

The influence of laser energy, irradiation position, photoelectric material, and anode voltage on the trigger characteristics of a pseudospark switch triggered by a 532-nm nanosecond focused laser is studied. The parameters of the seed electrons induced by the interaction between the focused laser and metal are measured. It is found that the increase of laser energy and anode voltage can increase the current density of seed electrons, reduce the time of electrons diffusion to the cathode hole, and thus reduce the trigger delay. When the irradiation position is close to the cathode hole, the surface electric field is larger, which is conducive to achieving a smaller trigger delay and jitter under low laser energy. The seed electron current induced by the focused laser has two peaks. The first peak mainly corresponds to the thermal emission, with a short time delay and narrow pulsewidth, contributing to the trigger. The second peak mainly corresponds to the electrode surface ablation, with a long time delay and large pulsewidth, contributing little to the trigger. In this case, the electrode surface temperature is more important than the work function, so Cu has better electron emission characteristics than Mg. With the increase of laser energy, the number of electrons in high-energy components increases.