Atomic Vacancy Distributions Produced by Inner-Shell Ionization

Abstract

Average Land M-shell-vacancy distributions produced in the deexcitation of atoms that have been singly ionized in the K shell or one of the L subshells are derived from a comprehensive set of available experimental and theoretical data on radiativeand Auger-transition rates. The data are supplemented by new calculations in j-j coupling from nonrelativistic screened hydrogenic wave functions of the following radiationless transition rates; K-LL, K-LM, and K-LN for selected elements with 20 -Z&8]. , and L&-MM, L;-MX, and L;-XY for 26 «Z~9 3. Experimental and theoretical data on Augerand radiative-transition probabilities are critically compared. Auger-electron intensity ratios and K@2/Kn& and KP/Ko. x-ray intensity ratios from a best fit to experimental data are tabulated for even atomic numbers from 20 to 94. The probability, per initial K vacancy, of vacancy production in each L; subshell is derived from experimental data and tabulated for 20~Z~94; components due to Auger and xray transitions are listed separately. These probabilities agree well with purely theoretical vacancy distributions also derived here. The probability of M-shell -, vacancy production in the decay of K and L& vacancies is derived from theory and tabulated for selected atoms with 16~Z~93.

Orbital electron capture by the nucleus

“…Atomic rearrangements that take place after the decay process are not included in this discussion, even though x rays emitted in the course of such rearrangements have led to the discovery of the process (Alvarez, 1937(Alvarez, , 1938a and constitute the most readily detectable signals indicating that capture has taken place. Details of the rearrangement process have been surveyed by Rao et al (1972) and Bambynek at al. (1972).…”

Measurements of absoluteK-shell ionization cross sections andL-shell x-ray production cross sections of Ge by electron impact

“…The x-ray emission rate, fluorescence yield, radiative, and nonradiative yields for transitions of vacancies from the K shell to the L 3 subshell, Coster-Kronig yields between L subshells and the intrashell radiative yield for transitions of vacancies from the L 1 subshell to the L 3 subshell used in this work, taken from Scofield [26], Krause [28], and Rao et al [30]. [23]; dotdashed curves, the formula of Gryzinski [24]; continuous curves represent the DWBA calculation of Segui et al [3].…”

“…Indeed, Krause conservatively recommends 20 % uncertainty for L3 , 15 % for f 12 , 10 % for f 13 , and 20-30 % for f 23 . In order to facilitate the comparison, we have adopted the fractional emission rate given by Scofield [26], the fluorescence, Coster-Kronig and intrashell radiative yields given by Krause [28], and the radiative and nonradiative yield for vacancies of the K shell to the L 3 subshell given by Rao et al [30], which are summarized in Table II. Figure 5(a) compares our Ge L␣ cross section measurements with the DWBA calculations of Segui et al [3] and the analytical formulas of Gryzinski and Casnati et al No experimental measurements were found in the literature to compare our results with.…”

Vacancy Transfer Probabilities from K to L Shell for Low Atomic Number Elements at 5.96 keV

“…The measured values of the K to L shell vacancy transfer probability, η KL , for 6 elements namely, S, Cl, K, Ca, Sc and Ti, are listed in the Table. This experimental values η KL are compared with the theoretical values calculated by Rao et al [16].…”

“…Ertuğral et al measured K to L shell vacancy transfer probabilities using intensity ratios of K α and L x total X-rays [1] and I Kβ /I Kα intensity ratios [14][15] for some elements in different atomic regions. Rao et al [16] have calculated the values of η KLi (i = 1, 2, 3) for elements in * corresponding author; e-mail: birolertugral@hotmail.com the atomic range 20 ≤ Z ≤ 94. In these calculations, the contributions due to Auger and radiative transitions were derived using the best fitted experimental data on the fluorescence yields and intensity ratios of different components of KLX (X = L; M; N, etc.)…”