UV-preionization in non-chain HF lasers with a self-sustained volume discharge to initiate chemical reaction.- Is it actually essential?

摘要

A role of UV preionization in non-chain HF(DF) lasers has been investigated. The influence of preionization on the discharge uniformity and on the duration of stable burning of a self-sustained volume discharge (SSVD) in working mixtures of non-chain HF lasers as a function of the energy stored in capacitors are comprehensively studied. Also presented are discharge photographs taken under identical conditions with and without preionization. It is shown that SSVD characteristics and laser energy are scarcely affected by preionization if the discharge lasts more than 150ns and the cathode surface area is in excess of 300cm~2. In HF lasers with the cathode surface area and discharge duration of less than 300cm~2 and 150ns, respectively, preionization is essential for nothing but stabilization of the discharge voltage and breakdown delay and for improving discharge uniformity. If the opposite takes place preionization has no influence on the laser characteristics.