Proceeding of Int.Conf. USA SPIE, v.2987, p.216-226, (1997). RATIONAL PUMPING SYSTEM FOR HIGH-POWER INDUSTRIAL CO2 LASER

Our original pumping system for the gas-discharge TE CO2-laser was tested in the 5 kW laser. It includes crossed electrodes (20 anodes, 5 cathodes), thyristor inverter (2.5 kHz), system of unballast connections of sections to the inverter. The preionizer placed upstream realizes the 100 kHz discharge through dielectric electrodes. On the basis of the principle of minimum of energy dissipation high efficiency of current distribution over crossings (20×5) with a small number of sections (20+5) is shown. It provides a stable DC discharge at average power input to 4W/cm3 due to influence of upstream discharges upon the downstream ones. The active medium of the laser was studied by method of IR luminescence at the wavelength 2-8 µm in "switched on " and "switched off " resonator. The luminescence intensity in the band 4.3 µm gives the particular information about the active medium. The 2D model of a discharge segmented along the gas flow was constructed to describe the distribution of electrical, gas-dynamic and kinetic characteristics. It was shown that in the most volume of chamber the discharge burns in the recombining plasma at reduced E/n, thus favoring high excitation efficiency