Significant Decrease in the Breakdown Threshold Voltage of the Commercial Laser Flash Lamp under kHz Pumping

Abstract

For the first time, to our knowledge, a multiple (to a factor of 3) reduction of the breakdown threshold of commercial cylindrical laser flash lamps with capacitive (through lamp electrodes) high-frequency (HF) pumping (19-3000 kHz) in comparison with a DC breakdown threshold is observed. When operating at a frequency of 400 kHz, a proportional decrease in the HF breakdown threshold is detected for a twofold increase in the relative dielectric permittivity ε when air as a cooling agent (ε = 1) is replaced by capacitor oil (ε = 2). An increase in ε to 21 in acetone is accompanied by a 30% decrease in the breakdown threshold and its subsequent stabilization with an increase in ε to 81 (in water). It is found that the breakdown threshold dispersion has two stages: an abrupt drop with a high (0.1–0.2 kV/kHz) slope in the range of 0–19 kHz and a smooth (~30%) decrease with increasing frequency to 3000 kHz.