TheK-fluorescence yield of chlorine and bromine

Abstract

Using a multiwire proportional counter with CH 4 and Ar as counting gases, the Kfluorescence yield of chlorine was determined to be COK = 0.101_+ 0.004, and the Kfluorescence yield of bromine was found to be co X =0.626+0.012. The respective sources were 3TAr and 81Kr, the latter produced by a (n, 7)-reaction from 8~The o)K-value of chlorine correlates with the theoretical computation of Walters and Bhalla [1], compared to that of bromine, which seems to confirm the theory of Kostroun et al. [18].

An accurate determination of the K‐shell X‐ray fluorescence yield of silicon

“…In this case, a multiwire ‘wall‐less’ proportional counter was used, which permits near‐complete collection of photoelectric de‐excitation events by subtracting off the events that escape the detector active volume . Independent measurements of the K Auger spectrum, under low gas pressure, and the total (K Auger and K X‐ray) spectrum, under high‐ Z , high gas pressure, are used in a ratio to render the absolute X‐ray intensity contribution . The primary limitation with this method is the large uncertainty that arises in the consideration of incomplete charge collection and interactions at the detector boundary.…”

“…Results reviewed here originate from the four aforementioned experimental approaches . They are identified in Figure in the form of ratios relative to the Walters and Bhalla predictions; measurements lower than Z = 10 have not been included; here, the agreement of measurement with theory tends to be quite poor and the associated uncertainties are high.…”

“…Open symbols indicate cases where the target element was incorporated within a molecule. References are identified as follows: ‐ McGuire (1970); ‐ Chen et al (1980); ‐ Epenschied and Hoffman (1978); ‐ Bailey and Swedlund (1967); ‐ Sole et al (1993); ‐ Dick and Lucas (1970); ‐ Beckhoff (2008); ‐ Bailey and Swedlund (1967); ‐ Brunner (1987); ‐ Campbell et al (1998); ‐ Pahor et al (1972); ‐ Pahor and Kodre (1968); ‐ Pahor et al (1972).…”

“…[20] Independent measurements of the K Auger spectrum, under low gas pressure, and the total (K Auger and K X-ray) spectrum, under high-Z, high gas pressure, are used in a ratio to render the absolute X-ray intensity contribution. [21,22] The primary limitation with this method is the large uncertainty that arises in the consideration of incomplete charge collection and interactions at the detector boundary. Small X-ray contamination in the Augeronly spectrum is also an issue.…”

K-shell fluorescence yields for elements with 6≤Z≤99

“…The K-shell fluorescence yield of an atom is defined as the probability that a vacancy in the K-shell is filled through a radiative transition. Several attempts have been made, in a tabular form, for measuring (Al-Nasr et al, 1987;Arora et al, 1981;Ahmad, 1979;Broyles et al, 1953;Bertrand et al, 1959;Bambynek et al, 1965;Brabets et al, 1959;Balakrishna et al, 1994;Brunner, 1987;Bhan et al, 1981;Famoux, 1985;Casnati et al, 1991;Chen et al, 1979;Drever and Moljk, 1957;Durak and Sahin, 1998;Erman and Sujkowski, 1961;Espenschied and Hoffmann, 1978;Egorov et al, 1989;Fairbrother et al, 1957;Forest and Easterda, 1959;Freedman et al, 1977;Frey et al, 1958;Garg et al, 1985;Godeau, 1961;Gray, 1956;Graham and Merritt, 1961;Apaydın and Tıras -oglu, 2006;Geidelman et al, 1988;Gurov et al, 1981;Harrison et al, 1955;Han et al, 2007;Heintze, 1955;Hagedoorn and Konijn, 1957;Hagedoorn and Wapstra, 1960;Hoffman and Dropesky, 1958;Hribar et al, 1977;Konstantinov et al, 1961;Kramer et al, 1962;Kramer, 1961;Konstantinov et al, 196...…”