Light Pulse from Halogen-Quenched GM Counter Discharges

Abstract

The light pulses associated with the halogen-quenched Geiger-Muller discharge of three commercially available end-window counters have been observed with a photomultiplier. Two of the counters were geometrically identical and filled to approximately the same pressure with neon and argon, respectively. The third tube was physically larger and contained neon. An individual light pulse, the duration of which is very much shorter than the corresponding normal voltage pulse, has a reproducible and distinctive shape. The amplitude of the light pulse and reciprocal of its risetime increase approximately linearly with increasing overvoltage. Arguments are given that relate the rise time to the velocity of propagation of the discharge. The smaller of the two neon tubes displayed double pulses over its entire Geiger region while the other tubes seemed entirely free of this phenomenon.