Compton scattering of 20- to 40-keV photons

Abstract

The scattered-energy spectra of monochronized synchrotron-radiation photons toward 90\ifmmode^\circ\else\textdegree\fi{} by C, Al, Fe, Cu, Au, and Pb samples were measured using high-purity Ge detectors to obtain incoherent scattering function (S) in the 1.14x2.28-A${\mathrm{\r{}}}^{\mathrm{\ensuremath{-}}1}$ region. The multiple-scattering intensity was evaluated by a Monte Carlo calculation while considering the Doppler broadening of the Compton-scattered photons and the photon linear polarization. The measured S of C, Al, Fe, and Cu agreed with that based on the Waller-Hartree theory (${\mathit{S}}^{\mathit{W}\mathit{H}}$), as well as that based on a relativistic impulse approximation (${\mathit{S}}^{\mathit{I}\mathit{A}}$) within the experiment error (2.5%). The measured S of high-Z atoms (Au and Pb) agrees with ${\mathit{S}}^{\mathit{I}\mathit{A}}$ and is smaller than ${\mathit{S}}^{\mathit{W}\mathit{H}}$ by 3--6 %.