Gamma-Ray Compton Scattering: Experimental Compton Profiles for He,N2, Ar, and Kr

A technique is described for measuring Compton profiles using a ${\mathrm{Te}}^{123m}$ 160-keV $\gamma$-ray source together with a Li-drifted-germanium detector. By studying He and ${\mathrm{N}}_2$, whose Compton profiles have been previously measured using x rays and theoretically calculated, it is found that the $\gamma$-ray technique gives results which agree with both the theory and the previous x-ray measurements. Measured Compton profiles for Ar and Kr are also presented. These results would have been almost impossible to obtain by the x-ray technique because of the large photoelectric absorption of the low-energy x rays. The Ar and Kr results are compared with atomic Hartree-Fock calculations and found to agree at $q=0\mathrm{}$ within experimental error which is less than 1%. As a result of these studies, it is concluded that all elements and their compounds can now be studied by Compton scattering.