Ionization Following Internal Conversion in Xenon

• Published in: Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences Mathematical and physical sciences, 1957-08, Vol.241 (1225), p.141-152
• Main Authors: Pleasonton, Frances, Snell, A. H.
• Format: Article
• Language: English
• Subjects: Atoms; Augers; Electrons; Fluorescence; Internal conversion; Ionization; Ions; Lead; Radioactive decay; Xenon
• ISSN: 1364-5021; 0080-4630; 1471-2946; 2053-9169
• DOI: 10.1098/rspa.1957.0119

The predominant internal conversion accompanying the decay of 12-day 131Xem from its metastable nuclear level to its stable ground state usually leaves the atoms in states of high multiple ionization, even though only a single primary electron vacancy is created in the initial process. The differential charge spectrum of the ions has been measured by the methods of magnetic analysis. Only 0.62 ± 0.08% of the decays leave the atom singly charged. The most probable state of ionization is 8, following 21.06 ± 0.21% of the nuclear transitions, and corresponding to the depopulation of the outer electron shell. Thereafter the probability of occurrence decreases toward the higher charges, twenty electrons being thrown off in 0.003 ± 0.002% of the decays, which presently is about as far as the sensitivity of the spectrometer carries the spectrum. The mechanism of this multiple ionization is discussed in terms of successive Auger events. An analysis of the intensity of the singly charged ions in particular, suggests that they result predominantly from a combination of direct internal conversion in the outer shell of the atom and of K-shell conversion followed by the (1s-5p) X -ray transition. The upper limit thereby set for the 5p shell conversion coefficient is 0.28, and the upper limit for the intensity of the (ls-5p) line is 0.011 in a total K-series intensity of 1.