Relative Energy Loss to Optical and Acoustic Modes of Electrons in Avalanche Breakdown in Ge

Expressions are derived for the rates of loss of high-energy electrons in a many-valley band structure to acoustic and optical modes. Evaluating these for germanium, for which all the parameters are now reasonably well known, we find that, contrary to what is usually assumed, the rate of loss to acoustic modes is greater than that to optical modes for electron energies of the order of the energy gap.