Measurements of mass attenuation coefficients and determination of photoionization cross sections at energies across the Li (i=1–3) edges of 66Dy

• Published in: Radiation physics and chemistry (Oxford, England : 1993) England : 1993), 2017-07, Vol.136, p.30-37
• Main Authors: Kaur, Rajnish, Kumar, Anil, Osan, Janos, Czyzycki, M., Karydas, A.G., Puri, Sanjiv
• Format: Article
• Language: English
• Subjects: Absorption; Absorption edge jump ratio; Atoms & subatomic particles; Attenuation coefficients; Cross-sections; Dysprosium isotopes; Mass attenuation coefficients; Mathematical models; Measurement; Photoionization; Photoionization cross sections; Radiation; Synchrotron radiation
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2017.03.028

The absolute values of the mass attenuation coefficients have been measured at sixty two photon energies across the Li (i=1–3) sub-shell absorption edges of 66Dy covering the region 7.6–14.0keV in order to investigate the influence of near-edge processes on the attenuation coefficients. The present measured attenuation coefficients are found to be higher by up to 10% than the theoretical values evaluated from the computer code XCOM (Berger et al., 2010) and the self-consistent Dirac-Hartree-Slater (DHS) model based values tabulated by Chantler (1995) over the energy region 7.6–14.0keV, except at energies in vicinity (few eV) of the Li (i=1–3) sub-shell absorption edge energies where the measured values are significantly higher (up to 37%) than both the sets of theoretical values. Further, the Li (i=1–3) sub-shell photoionization cross sections, (σLiP)exp, deduced from the present measured mass attenuation coefficients are compared with the non-relativistic Hartree-Fock-Slater (HFS) model based values tabulated by Scofield (1973) and those evaluated from the theoretical total photoionization attenuation coefficients tabulated by Chantler (1995). The deduced (σLiP)exp(i=1–3) values are found to be in better agreement with those evaluated from the tabulations given by Chantler (1995) than the values given by Scofield (1973) over the energy region 7.8 – 14.0keV included in this study. However, at photon energies up to few eV above the Li edges, the deduced (σLiP)exp(i=1–3) values are found to be significantly higher (up to 32%) than both the sets of theoretical values. •Absolute mass attenuation coefficients measured at photon energies across the Li (i=1–3) edges of 66Dy.•The measured values compared with those obtained from XCOM and the DHS model based values.•Li (i=1–3) subshell photoionization cross sections for 66Dy deduced from measured mass attenuation coefficients.