skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Angular distribution of Au and U L x-rays induced by 22.6-keV photons

Abstract

The angular distribution of the L x-ray fluorescent lines from Au and U induced by 22.6-keV x rays from a {sup 109}Cd has been measured. A Si(Li) detector having a resolution of 160 eV at 5.90 keV was used to detect these L lines over the angular range of 70 degree sign -150 degree sign . No strong anisotropy was observed as mentioned by some groups. In the case of Au, a maximum anisotropy of 5% was observed while for U it was within experimental errors (2%). From the angular distribution of the L1 line of Au, the alignment parameter was obtained and its value was found to be 0.10{+-}0.14.

Authors:
; ; ;  [1]
  1. Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)
Publication Date:
OSTI Identifier:
20982135
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.75.022901; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ALIGNMENT; ANGULAR DISTRIBUTION; ANISOTROPY; CADMIUM 109; FLUORESCENCE; GOLD; KEV RANGE 10-100; L SHELL; LI-DRIFTED SI DETECTORS; PHOTOIONIZATION; PHOTON-ATOM COLLISIONS; PHOTONS; RESOLUTION; URANIUM; X RADIATION; X-RAY SOURCES; X-RAY SPECTRA

Citation Formats

Santra, S., Mitra, D., Sarkar, M., and Bhattacharya, D. Angular distribution of Au and U L x-rays induced by 22.6-keV photons. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.022901.
Santra, S., Mitra, D., Sarkar, M., & Bhattacharya, D. Angular distribution of Au and U L x-rays induced by 22.6-keV photons. United States. doi:10.1103/PHYSREVA.75.022901.
Santra, S., Mitra, D., Sarkar, M., and Bhattacharya, D. Thu . "Angular distribution of Au and U L x-rays induced by 22.6-keV photons". United States. doi:10.1103/PHYSREVA.75.022901.
@article{osti_20982135,
title = {Angular distribution of Au and U L x-rays induced by 22.6-keV photons},
author = {Santra, S. and Mitra, D. and Sarkar, M. and Bhattacharya, D.},
abstractNote = {The angular distribution of the L x-ray fluorescent lines from Au and U induced by 22.6-keV x rays from a {sup 109}Cd has been measured. A Si(Li) detector having a resolution of 160 eV at 5.90 keV was used to detect these L lines over the angular range of 70 degree sign -150 degree sign . No strong anisotropy was observed as mentioned by some groups. In the case of Au, a maximum anisotropy of 5% was observed while for U it was within experimental errors (2%). From the angular distribution of the L1 line of Au, the alignment parameter was obtained and its value was found to be 0.10{+-}0.14.},
doi = {10.1103/PHYSREVA.75.022901},
journal = {Physical Review. A},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • Angular distributions of [ital L][sub 3] x-ray transitions, including electric-dipole-forbidden ones, were measured for 1-, 2-, and 3-MeV proton impact on a thorium target, where the excitation and detection systems were cylindrically symmetric. A sophisticated spectrum-analysis technique was applied, where both the Lorentzian broadening of the transitions and the Si(Li) detector response function with various tailing features were taken into account. The anisotropy-parameter ratios are expected to be independent of the ionization process, and to be characteristic of the x-ray transitions in the independent-particle model. The ratios of the anisotropy parameters of the electric-dipole-allowed transitions were in disagreement with thismore » expectation, even when the higher-order multipole contributions were taken into account. These results follow the same trend as earlier angular distribution and angular correlation measurements. Additionally, the electric-dipole-forbidden [ital Lt]([ital L][sub 3][ital M][sub 2]) and [ital Ls]([ital L][sub 3][ital M][sub 3]) transitions had a [ital P][sub 4](cos([theta])) term, which is not expected within the framework of the single-particle-model predictions. Possible causes for this discrepancy are explored.« less
  • The angular distribution of Pb L1 and L infinity x-rays has been measured in the case of lead where the targets were typically 100 ..mu..g/cm/sup 2/ thick with a 400 ..mu..g/cm/sup 2/ layer of silver evaporated on each side. Spectra were obtained at 25, 45, 65, 90, 115, 135 and 155/sup 0/ and ratios of Pb L x-rays to the isotropic Ag K x-rays were taken. The most readily interpretable case is L1 since this transition involves only the Lm subshell. After correcting for x-ray absorption in the target assuming it to be layered (i.e., neglecting diffusion of the Agmore » in the Pb) a small deviation from isotropy is found which is expected due to enhanced depopulation of M = 0 substates at small impact parameter collisions. The velocity dependence of the alignment parameter A/sub 2/ has been calculated using PWBA and screened as well as unscreened wave functions. The results for agree with these calculations. Further work is under consideration.« less
  • The cross sections for the production of Ll, L..cap alpha.., L..beta.., and L..gamma.. x rays in the elements Ta, W, Au, Hg, Tl, Pb, Bi, Th, and U by photons of energies 17.781, 25.770, 32.890, and 43.949 keV have been measured, using a standard double-reflection experimental setup. The measured values have been interpreted in terms of the photoionization cross sections, fluorescence yields, Coster-Kronig transition probabilities, and radiative decay rates. A fairly good agreement is found between the experiment and calculations.
  • Ll, L..cap alpha.., L..beta.., and L..gamma.. x-ray-production cross sections have been measured in elements Ta, W, Au, Hg, Tl, Pb, Bi, Th, and U for 60-keV photons. The measured values have been interpreted in terms of photoelectric cross sections, fluorescence yields, Coster-Kronig transition probabilities, and radiative decay rates. A fairly good agreement is found between the experimental and calculated values.