Penetrating Showers of Cosmic Rays

Abstract

average (Ap/p) pur e=10.2±0.4XlO~5/atmos. was obtained for the pressure coefficient of resistance of germanium at 300°K. Assuming a compressibility 1.4XlO~6/atmos. and a coefficient of linear expansion 8XlO-fi /°C leads to a value AJE G /Ar=-0.87X10~4 ev/°C. This result is, with one exception, in excellent agreement with calculations from other experiments. Shockley and Bardeen 1 found for this constant the value -0.9X10~4 ev/°C using data on the mobilities of holes and electrons; their result is proportional to m c 6/4 . Johnson and Fan 2 have estimated from data on the temperature dependence of the Hall effect a value -1.1 X 10~4 ev/°C. Correction of this result by subtraction of the contribution of the lattice vibrations computed by Fan 3 leads to the value -1.0 X 10~4 ev/°C for the contribution of the volume effect alone. Only the latter value is comparable to the results of the pressure measurements; the uncorrected result of Johnson and Fan, which depends on (m e mh) zii , includes both the volume effect and the change in lattice vibrations which accompany a change in temperature. Fan, 4 using data from optical absorption measurements found the quite different value -4.0X10" 4 ev/°C.