Internal resonance Raman scattering of characteristic target K x rays in thick silicon targets

A four-inch curved-crystal spectrometer has been used to investigate the internal resonance Raman scattering (IRRS) process in Si K x-ray spectra induced by 1.5- and 2.0-MeV proton bombardment of thick targets. The IRRS process involves the scattering of characteristic target Kα/sub 1,2/ radiation off of the L shell of a neighboring target atom. The scattered photons exhibit an edge-shaped structure at approx. 1640.5 eV which tails off at low energies. A thick-target analysis has been used to obtain a partial scattering cross section for scattering within the observable energy range 1634 < or = E/sub f/ < or = 1640.5 eV, which is in reasonable agreement with our calculations based on second-order perturbation theory. Based on the partial cross section, we are able to estimate the total IRRS cross section for scattering into all angles and all allowed energies (0 < or = E/sub f/ < or = 1640.5 eV) to be (58 +- 20) r20 or (4.6 +- 1.6)10-24 cm2