The paper deals with recent data of investigations and medical adaptations of waveguide CW and TEA carbon dioxide lasers with flexible fibers. The silver halide polycrystalline fibers with lengths up to 1 .8 m and diameters 0.5-2.0 mm are used. Main attention is paid to transmission of high power radiation and reducing of output beam divergence. Power at the fiber end is up to 43 W in case of CW laser and 100 kW (pulse duration -100 ns) with TEA laser. For long-lived work it is needed to halve power. The magnitude of output radiation divergence equal to 6 degrees (full angle) for uncladded fiber with 1 mm diameter has been achieved.

Electrical and mass-spectrometric studies of a glow discharge produced by a direct current positive voltage applied to a point-to-plane gap in low-pressure dry air have provided many useful results, which help to clarify the interaction of the underlying physical mechanisms. Systematic studies of this discharge show that electrical parameters and gas pressure influence drastically the cold plasma behaviour. A discharge state similar to that of Townsend is obtained for a restricted region of operation while, outside this region, similarity rules seem not to be fulfilled. The main ions detected during the Townsend-like discharge are 0 :and NO+ while, after breakdown, dissociation products such as O+ and N+ as well as N : ions are detected. It has been found that ion detection depends strongly upon cathode dark space structure.