Measurement of the Differential Cross-Section for Compton Scattering by Bound Electrons.

Singly differential cross sections for incoherent scattering by K-shell electrons were measured for incident photons having energies of 662 keV, 320 keV and 145 keV. The spectral distributions of scattered photons were examined. Target materials were iron, tin, holmium, and gold at 320 keV; tin and gold at 662 keV; and iron and tin at 145 keV. It was not possible to draw specific conclusions from the 145-keV data. A typical spectrum at 320 keV consisted of a scattered peak which was much narrower than would be expected from the bound state electron motion. Rather than monotonically increasing with atomic number as expected, the peak width reached a maximum near Z = 50 and then decreased with increasing atomic number. The peak also reached a maximum width for a scattering angle between 45 and 60 deg. The same angular behavior was observed at 662 keV and the peaks in the gold spectra were narrower than corresponding peaks in the tin spectra.