Studies of Stimulated Emission from Discharges in Air and Nitrogen in the Pressure Range 1-760 torr

Stimulated emission from gas discharge tubes built up of ceramic disc capacitors (C = 3 000 pF) separated by electrodes and having a central hole (discharge channel) has been studied. Nitrogen has been used as test gas. It is shown that the output power density is appreciably higher from this tube when fed by a high voltage pulse generator than from an ordinary straight tube with end electrodes. 230 kW pulses (superradiant mode without mirrors) have been observed from a tube 7 mm in bore and 102 mm long at at nitrogen pressure of 175 torr. The pulse duration is approximately 2 ns. It is further shown that the stimulated emission occurs during breakdown. In a similar tube with aluminium oxide discs (er = 8) instead of the disc capacitors, laser action has been observed at considerably higher pressure. In air at atmospheric pressure an output of 25 kW has been achieved from a tube 4 mm in bore and 102 mm long. The pulse duration is in this case approximately 1 ns.