Abstracts of Bell System Technical Papers Not Appearing in this Journal (01 January 1929)

Reflection and Refraction of Electrons by a Crystal of Nickelr C. J. and L . H . GERMER . This is a report of further observations on the regular reflection of electrons from the surface of a nickel crystal; an earlier report was published in the same journal. 3 In the present report data are given of the selectivity of reflection for angles of incidence from 10 to 50 degrees, and for electrons of wave-lengths 0.6 to 1.5 A. The previously found result is confirmed t h a t to explain the occurrence of the intensity maxima of the reflected beam it is necessary to assume that electron waves are refracted on passing into the crystal. The data are used for calculating indices of refraction for nickel for electrons of various speeds or wave-lengths, and a dispersion curve is constructed. 

This curve displays a feature suggestive of the optical phenomenon of anomalous dispersion. DAVISSON Optical Experiments with Electrons.4 L . H. GERMER . A semipopular account of a series of experiments performed by C. J. Davisson and the author upon the scattering of electrons by single crystals of Journal of the A. I. E. E., October 1928, pp. 737-741. - Proceedings of the National Academy of Sciences, August 1928, pp. 619-627. 3 Proceedings of the National Academy of Sciences, April 1928, pp. 317-322. 4 Journal of Chemical Education, Part I, Sept. 1928, pp. 1041-1055. Part II, Oct. 1928, pp. 1255-1271. 209 1 210 BELL SYSTEM TECHNICAL JOURNAL nickel. These experiments establish the fact that under certain conditions moving electrons behave like trains of waves.