Semiconductor Excitation Sources for Bistatic Laser Monitors

Abstract

The paper presents the results of the development of the semiconductor excitation sources for active media on self-terminating transitions in metal vapors. The excitation source consists of 10 identical commutation cells. Each cell contains a storage capacitor, a powerful IGBT transistor HGTG27N120BN and a transformer on a toroidal ferrite core B64290L0082X095. An operating principle is a simultaneous switching of cells, as a result of which storage capacitors are discharged through transformers to an active medium - it makes it possible to generate an excitation pulse with a required amplitude and rise time. The waveforms of the current and the voltage pulses are presented on an active load and a gas discharge tube (GDT) of the small-sized brightness amplifier (l=40 cm, d=2.5 cm, V=196 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ). The amplitude of the GDT current at a power supply of 420 V was 40 A. The rise time was 42 ns. The peaking capacitor of 330 pF increased the amplitude of the GDT current up to 51 A (by approximately 16 %). The radiation power of the active element at an oscillator mode was 665 mW at the nominal operating conditions (f=21 kHz, P=465 W). The operation of two identical excitation sources was synchronized with the jitter no more than 4 ns.