Operation of pressed cathodes in helium-neon lasers

The operation of pressed cathodes made from a mixture of barium scandate and refractory metals was investigated in OKG-11 helium-neon lasers. A comprehensive study was made of changes in the composition of the gaseous mixture, the electron temperature in the discharge plasma, and the emission current from the cathode during its operation. It was found that after 1600-h operation the parameters of the laser output remained constant. The cathode could be operated at a temperature about 100° below the nominal value in vacuum (brightness temperature 1070°C).