Experimental and theoretical studies of the breadth and structure of the Compton shifted line

Citation

DuMond, Jesse William Monroe (1929) Experimental and theoretical studies of the breadth and structure of the Compton shifted line. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-03092005-100120

Abstract

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In October 1922, Arthur Compton discovered that monochromatic X radiation when scattered by elements of low atomic number contains longer wave lengths not originally present before scattering in addition to the initial primary line. This "softening" by scattering had been observed previously by absorption methods in a qualitative way, but Compton’s discovery consisted in showing quantitatively the precise nature of this shifted radiation, namely, that it appeared as a rather broad diffuse "line" differing in wave length from the primary line by a wavelength difference of [...].

Subsequently other investigators, Compton and Woo, Webster, Ross, Becker, Sharp, Allison and Duane, Dauvillier and many others obtained both by photographic and ionization chamber methods definite evidence for the existence of the "shifted" line. Almost invariably this shifted line has appeared broader and more diffuse than the unshifted line which almost always accompanies it. The primary line generally used is the [...] doublet with a separation between its components of 4 [...]. The author knows of only one case in which this doublet appears even faintly resolved in the shifted position though it is almost always partially resolved in the unshifted positions. This exceptional case is a photograph taken by Ross of the scattered radiation from a moleybdenum target with aluminum as the scatterer. This photograph remains unexplained today. It has not been reproduced.

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