Observation of a New Component in the X-Ray Scattered Spectrum

Abstract

The results of a spectral analysis of Cu $K{\ensuremath{\alpha}}_{1}$, $K{\ensuremath{\alpha}}_{2}$ x-rays scattered by a single crystal of LiF (lithium fluoride) and by LiF powder (at scattering angles 16\ifmmode^\circ\else\textdegree\fi{}, 25\ifmmode^\circ\else\textdegree\fi{}, 70\ifmmode^\circ\else\textdegree\fi{}, 84\ifmmode^\circ\else\textdegree\fi{}) are evidence of the existence of a new line on the long-wavelength side of the spectrum. This line is 5 eV from the incident beam, and its position and shape are independent of the scattering angle. The peak intensity of the new line is of the same order of magnitude as the Compton intensity. The observed line can be considered to be caused by an "x-ray Raman"-type process from $F$-centers which themselves were produced by the incident x-ray beam. This is not the only possible explanation. However, the position of the line is comparable to the $F$-center absorption energy for LiF as measured by an ultraviolet spectrometer. The relative peak intensity indicates that the differential cross section for the process presently under investigation is higher than the Compton cross section for valence electrons.