ON DISCHARGE MECHANISM IN SPARK TRACK CHAMBERS

The operation of streamer chamber has been studied by application of image converter and image intensifier. The high voltage pulse was produced by a Marx generator (pulse duration about 15 ns), the primary ionisation was generated by gasionizing radiation emitted by a spark lamp. There exist two modes of operation: 1. When only about one primary electron per 2 cm was available, the discharges were identified as to be avalanches, which developed into anode- and cathode-directed streamers, as soon as critical amplification was attained. The first 5 ns after beginning of streamer mechanism, when E/p was large, streamer propagation depends strongly on E/p; the velocity of anode-directed streamer is somewhat larger than that of cathode-directed streamer. When pulse magnitude decreases strongly, the streamer velocities become nearly independent of E/p. 2. Starting with about 100 electrons/cm, one gets tracks, which emit sufficient light for direct photography. The tracks are parallel to the direction of the ionizing radiation and are caused by overlapping of the local avalanches initiated by the primary electrons. © 1968 Springer-Verlag.