Experimental determination of absolute-scale compton cross sections using the K X-ray escape and a comparison with three versions of the impulse approximation

• Published in: Radiation physics and chemistry (Oxford, England : 1993) Vol. 73; no. 6; pp. 303 - 310
• Main Authors: Pašić, S., Uroić, M., Tocilj, Z., Majer, M., Gamulin, O., Bokulić, T., Ilakovac, K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2005
• Subjects: Absolute-scale measurement; Compton cross-section; Compton scattering; Impulse approximation; Compton cross-section; Impulse approximation; Compton scattering; Absolute-scale measurement; 32.80.Cy
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2005.04.001

Double-differential Compton cross sections at two incident photon energies of 68.9 and 70.8 keV (mercury Kα X-rays) at the scattering angle of about 172° were measured in germanium using the coincidence technique with a detector as the scatterer. The cross sections were determined by normalization of the Compton spectra to the peaks due to the escape of characteristic Kα and Kβ X-rays from the target detector. This new approach of determination of absolute-scale Compton cross sections can also be applied in widely used single-mode measurements (source–scatterer–detector assembly). Our analysis shows that the new method is especially convenient and accurate at lower incident photon energies above the K-edge in the target atoms. The experimental results are compared with the non-relativistic impulse approximation, the frequently used simplified version of the relativistic impulse approximation and the non-relativistic impulse approximation used with the relativistic expression for the atomic electron momentum in the direction of the photon momentum transfer. Contrary to our expectation, the non-relativistic impulse approximation clearly gives the best agreement with the experimental data in the region of the Compton peak.