Absolute-scale measurement of compton backscattering in germanium at 105.3 keV

The differential cross section d(2)sigma /dE d Omega was measured at an incident photon energy of 105.3 keV in germanium on absolute scale. The measurements were made using two high purity Ge detectors that operated in a coincidence mode. One detector served as the target and detector of ejected electrons, and another as the detector of Compton-scattered photons. It was found that fast (multiple) cascades have little influence on the data of the 105.3 keV crossover transition. An improved determination of the detector efficiency was made. The calculated values of the cross-section d(2)sigma /dE d Omega using the impulse approximation (IA) with Hatree-Fock (HF) wave functions are in excellent agreement with the experimental cross-sections, while the IA with hydrogen like (HL) wave functions give fair agreement. A comparison of the calculated values of the cross-sections obtained with HF and HL wave functions for each subshell in germanium gives new values for effective charges, which improve agreement between the results of IA with HL and experimental values. (C) 2001 Elsevier Science Ltd. All rights reserved.