GAS EVOLUTION FROM ELECTRICAL-INSULATION MATERIALS IN THE 200-1000 degree C TEMPERATURE RANGE.

The new ABN - 1 and BNTs electrical-insulation materials are finding extensive application in plasma-accelerator construction. The purpose of this paper is to determine the particle flux caused by gas evolution from these electrical-insulation materials (resistivity rho equals 2 multiplied by (times) 10**4 OMEGA multiplied by (times) cm temperature T equals 2000 degree C; specific weight d equals 2-3 g/cm**3). The magnitude of the gas flux as a function of the temperature of the sample was determined in the experiment. The investigated sample was placed into a closed volume whose magnitude was known and remained constant during the entire experiment. The criterion of the quantity of evolved gas was the magnitude of the pressure change in the volume with the sample placed inside it when the volume was disconnected from the evacuation system. It is established that the maximum specific rate of gas evolution is in the range from 2. 8 to 3. 8 liters multiplied by (times) mu /sec multiplied by (times) cm**2 and reaches the indicated extreme values at 400 and 1000 degree C. Consequently, in calculating high-vacuum systems of test chambers, it is necessary to take account of the gas fluxes from the investigated electrical-insulation materials.