Abstract
A simple theoretical expression is proposed for K quanta production in directions at large angles to the surface of a thick target, neglecting absorption. Direct and indirect production are calculated and the ratio of indirect to total production is shown to be in agreement with experimental results both in magnitude and in independence of over-voltage U0. Total production is expressed as a function of atomic number Z and over-voltage U0, and is found to vary as (U0 - 1)1 67. Values for total production are in fair agreement with experimental values.