A classical theory of scattering of an electron beam by a laser standing wave (the Kapitza-Dirac effect) is presented. The prediction of the theory is in good agreement with all the experimental results which were reported independently by Bartell et al., Schwarz et al., Takeda et al., and Pfeiffer. This shows that the interaction of a free electron with coherent radiation is basically a classical process.

• Received 12 September 1978

DOI:https://doi.org/10.1103/PhysRevA.20.294