Eine Untersuchung der Elektronenkomponente von Elektronenlawinen

Abstract

The oscilloscopic study of pulses due to the electron component of avalanches in homogeneous fields confirms that the number of electrons increases exponentially with time. Measuring drift velocityv ₋ and applying recent measurements of the first Townsend coefficient α, we find the time constant τ to be equal to 1/α ·v ₋ as was expected. -We get the axial diffusion radius of the electron swarm and thus the mean energy of agitation (0.4 to 0.7 eV) and the cross section for electron impact. -Space charge influence becomes apparent with carrier numbers of about 10⁷ electrons, attenuating the temporal rate of further growth of the avalanche. This is in accordance with earlier work on avalanches done in our institute.

The investigation was made with methane in the range of E/p from 28 to 58 V/cm · mm Hg, with pd-values from 50 to 1500 cm · mm Hg, with mean gas amplification from e¹² to e¹⁷, and with gap widths of 2, 3, and 6 cm.