Measurement of L Shell X-Ray Production and Average L Shell Fluorescence Yields for Some Heavy Elements at 123.6 keV (original) (raw)
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Experimental determination of L-subshell fluorescence yields for heavy elements at 59.54�keV
Journal of Analytical Atomic Spectrometry, 2001
L-shell X-ray production cross-sections have been measured for selected heavy elements with 70¡Z¡92 at 59.54 keV using a Si(Li) detector. The L-subshell X-ray fluorescence yields v 1 , v 2 and v 3 have been derived using the experimental L X-ray production cross-sections, theoretical L-subshell photoionization cross-sections, Coster-Kronig transition probabilities and fractional X-ray emission rates. The data obtained are compared with the literature experimental data, theoretical predictions based on Dirac-Hartree-Slater wave functions and semi-empirical compilations.
L X-ray fluorescence cross-sections of heavy elements excited by 16.04, 16.90 and 17.78 keV photons
Radiation Physics and Chemistry, 1999
L l , L a , L b , L g X-ray¯uorescence cross sections have been measured for the elements Au, Pt, W, Lu, Yb, Tm, Ho, Dy and Tb using photon energies of 16.04, 16.90 and 17.78 keV. Measurements have been performed using an X-ray tube with a secondary-exciter system as an excitation source. The secondary exciters used are Zr, Nb and Mo of pure metal sheets (99.99%). A Mo X-ray tube with a secondary-target arrangement was used to obtain high intensity with a high degree of monochromaticity. Using an X-ray tube made it possible to measure X-raȳ uorescence cross-sections and intensity ratios even for low intensity X-ray lines. The experimental values of the cross-sections were determined by measuring the absolute yield of L subshell X-rays emitted from a standard target of a given element irradiated with photons of given energy. The theoretical values of the cross-sections were calculated using theoretically tabulated values of subshell photoionization cross-sections,¯uorescence yields, Coster± Kronig transition probabilities and radiative decay rates. Experimental results have been compared with the theoretically calculated values of L X-ray cross-sections. A fairly good agreement is observed between the experimental and the calculated values. The intensity ratios I Lb /I La and I Lg /I La were measured and found to be in good agreement with the calculated values. #
Spectrochimica Acta Part B: Atomic Spectroscopy, 2001
. Total M-shell X-ray production cross-sections MXRP for selected heavy elements between Yb and U at have Ž . been measured at 5.96 keV incident photon energy using a Si Li detector. The average M-shell fluorescence yields have been derived, using the experimental total M X-ray production cross-sections and theoretical M-shell photoionization cross-sections. Extracted cross-sections and fluorescence yields have been compared with the literature experimental values, theoretical predictions and semiempirical fits. ᮊ
Journal of Radioanalytical and Nuclear Chemistry, 2000
In case 1, the excitation energy (E) is less than the binding energy of the L 2 subshell but sufficient to excite the L 3 subshell. In case 2, E is less than the binding energy of the L 1 subshell but sufficient to excite the L 2 subshell. In case 3, E is less than the binding energy of the K shell but sufficient to excite the L 1 subshell. The applied method relies on photoionization of consecutive subshells and detection of the resolved fluorescence. The relative intensities in 8 different elements with atomic number ranging from 66-90 at 15 different excitation energies in the interval 8.265-21.705 keV have been measured.
Radiation Physics and Chemistry, 2001
L l , L a , L Z , L b and L g X-ray fluorescence cross-sections have been measured for the elements Yb, Lu, W, Hg, Tl, Pb, Bi and U using excitation energy of 59.543 keV. Measurements have been performed using an 241 Am annular source and a Si(Li) detector. The experimental values of the cross-sections were determined by measuring the absolute yield of L subshell X-rays emitted from a standard target of a given element irradiated with photons of given energy. The theoretical values of the cross-sections were calculated using theoretically tabulated values of subshell photoionization cross-sections, fluorescence yields, Coster-Kronig transition probabilities and radiative decay rates. Experimental results have been compared with the theoretically calculated values of L X-ray cross-sections. A fairly good agreement is obtained between the experimental and the calculated values. #
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1996
M-shell x-ray production/fluorescence (M XRF) cross-sections for five elements with 81 < Z < 92 were measured at 5.96-keV incident photon energy using thin targets. From the measured M XRF cross-sections the average M-shell fluorescence yields were derived. Experimental results for XRF cross-sections and fluorescence yields were compared with theory. The experimental results were found to be higher than the theoretical valws by 1047%. Further experimental investigations on M XRF cross-sections for more elements at different excitation energies are required in order to check the validity of the theoretical parameters used to calculate the M XRF crosssections.