IEEE TRANSACTIONS ON NUCLEAR SCIENCE, vol.49, no.4, pp.1622-1628, 2002 (SCI-Expanded)
We have demonstrated experimentally that the main breakdown-triggering mechanism in most gaseous detectors, including micropattern gaseous detectors, is sporadic electron jets from the cathode surfaces. Depending on the counting rate and applied voltages, each jet contains randomly from a few primary electrons up to 10(5), emitted in a time interval ranging between 0.1 mus to milliseconds. After the emission, these primary electrons experience a full gas multiplication in the detector and create spurious pulses.