Quantum Effects in the Interaction of Electrons With High Frequency Fields and the Transition to Classical Theory

The interaction of electrons with an electromagnetic field within a conducting enclosure is treated from the point of view of quantum mechanics. The various quantum effects to be expected with regard to energy exchanges are pointed out and it is shown how the various probabilities of energy change combine to give results in accord with classical theory for conditions where classical theory becomes appropriate. The details in the transition from quantum behavior to classical behavior are traced in a very illuminating way for two particular examples. The conditions under which quantum effects manifest themselves are given.