Samples of nominal composition Bi,_._,Pb,Sb,Sr,Ca,Cu,O (x = 0 -0.8, y = 0 -0.3) were prepared and investigated by x-ray, DTA, TG and microprobe analyses. T, was measured by resistive and magnetic (DC susceptibility) methods. The addition of antimony exerted a stabilizing influence on the formation of the 2223 phase, the solubility of Sb being 60.1 mole. The optimal temperatures of t h e formation of the 2223 phases with dinerent Pb a n d S b content are in the range 83W4O"C. Deviation from the optimal temperature of about 1-2°C can b e the cause of a sharp decrease in the volume of the 2223 phase. The anomalies at 240 K revealed a temperature dependence of resistance and magnetic susceptibility for some samoles with and without Sb

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The dependence of the specific energy of the high-pressure CO2 laser (4.1 and 1 1.1 atm) with the optical pumping on the resonator losses coefficient and density of the absorbed energy of radiation of the HF laser on transition P1 (8) is studied. The maximal values of the specific (200 J/l) and total (7 J) radiation energy of the high-pressure CO2 laser (1 1.1 atm) are obtained with coefficient oftransformation ofthe pumping radiation energy (X=2.78 jtm) to energy of the Co2 laser radiation (?=lO.6 tm) being equal to -49% (quantum yield 73%), and with parameter of excess of the unsaturated gain (go = 0.1 1/cm) above the lasing threshold (g) m = gc/g 4.

The efficient repetitively pulsed ( 1 0 Hz) HF chemical laser initiated by barrier electric discharge with electrode gap 10 cm was realised. In mono-pulse mode specific output energy 3 and 23 J/l, tecimical efficiency (ri) 3.4 and 26%, for nonchain and chain process, correspondingly, were obtained. In the repetitively pulsed (RP) mode of the laser operation at 10 Hz on the depleted fluorine-hydrogen mixture (20 % F2, 5 % H2) the mean laser power of 43 W was obtained (specific output energy E/V'40 J/l, r=l 1.3%). The computational prediction for laser operation in repetitively pulsed mode at active length of about 0.5 m has shown the possibility of achievement of the specific laser energy about 1 5 J/l and technical efficiency up to 20 % . Output laser specific energy 14 J/l under RPCL conditions at length of active medium 0.37 m in mono-pulse mode was obtained in a good agreement with numerical prediction.

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