Anomalous scattering factors of some rare earth elements evaluated using photon interaction cross-sections

Pramana

T K Umesh1¹  S B Appaji Gowda¹  M L Mallikarjuna¹  R Gowda¹ 

[1] Department of Studies in Physics, Manasagangothri, University of Mysore, Mysore 570 006, India$$

关键词: Rare earth elements;    photoeffect;    dispersion corrections ð?‘“' and ð?‘“''.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The real and imaginary parts, 𝑓'(𝐸) and 𝑓''(𝐸) of the dispersion corrections to the forward Rayleigh scattering amplitude (also called anomalous scattering factors) for the elements La, Ce, Pr, Nd, Sm, Gd, Dy, Ho and Er, have been determined by a numerical evaluation of the dispersion integral that relates them through the optical theorem to the photoeffect cross-sections. The photoeffect cross-sections are derived from the total attenuation cross-section data set experimentally determined using high resolution high purity germanium detector in a narrow beam good geometry set-up for these elements in the photon energy range 5 to 1332 keV and reported earlier by the authors. Below 5 keV, Scofield’s photoeffect cross-sections compiled in XCOM program have been interpolated and used. Simple formulae for 𝑓'' in terms of atomic number and energy have also been obtained. The data cover the energy region from 6 to 85 keV and atomic number 𝑍 from 57–68. The results obtained are found to agree fairly well with the other available data.

【 授权许可】

Unknown