Systematic study of proton-induced L-shell ionization for 46 ≤ Z ≤ 70 elements

Cesare, N. De; Murolo, F.; Perillo, E.; Vigilante, M.

doi:10.1016/0168-583x(93)95850-5

Cited by 6 publications

(3 citation statements)

References 26 publications

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“…Besides the corrections already introduced in the classical ECPSSR model of Brandt andLapicki (1979, 1981), i.e. energy loss, Coulomb deflection, binding and relativistic corrections, a modified treatment of the binding correction, corresponding to a united-atom approximation (ECPSSR-UA), suggested by our group (Vigilante et al 1990) and an extension of the relativistic calculations of Crasemann (1985, 1989), based on DHS wavefunctions, to heavy targets and for various projectiles (De Cesare et al 1993, leading at the end to the values of the cross sections labelled DHS-UA, were used. Recently, our group has proposed a Coulomb correction more sophisticated than the one generally used in the ECPSSR model.…”

Section: Theoretical Modelsmentioning

confidence: 99%

Proton- and⁴He-ion-induced L-shell ionization of Pt, Pb and Bi

Balsamo

Cesare

Murolo

et al. 1999

J. Phys. B: At. Mol. Opt. Phys.

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L-shell x-ray production cross sections on selected heavy elements (Pt, Pb and Bi), some of which are of great importance from a biological point of view, have been measured by proton and 4He ion impact at energies ranging between 0.3 and 3.2 MeV and between 0.6 and 1.8 MeV, respectively. The data have been compared with the results of other laboratories, whenever existing, obtaining an overall good agreement. L-subshell ionization cross sections have been extracted and compared with the predictions of various theoretical approximations in the description of the ionization process. The disagreement observed at low values of the reduced velocity parameter LR between the data and the predictions of the ECPSSR model is significantly reduced by using a united-atom approximation in the treatment of the binding correction, as suggested by our group (ECPSSR-UA), and by replacing the screened hydrogen-like wavefunctions with the more realistic Dirac-Hartree-Slater ones. The application of a modified Coulomb deflection correction, recently suggested by our group, has further reduced the remaining discrepancies, predominantly in the case of impinging 4He ions.

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Section: Theoretical Modelsmentioning

confidence: 99%

Proton- and⁴He-ion-induced L-shell ionization of Pt, Pb and Bi

Balsamo

Cesare

Murolo

et al. 1999

J. Phys. B: At. Mol. Opt. Phys.

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“…The very large ratios still present for the L 2 -subshell, also observed for other kinds of projectiles, have been attributed to vacancy rearrangement effects in the collision (Sarkadi and Mukoyama 1984). However, our analysis on 46 Z 2 70 elements (De Cesare et al 1993, 1994 has shown that the introduction of these effects through the two-step model of Sarkadi and Mukoyama (1984) leads throughout to slight improvements, although insufficient to reproduce the experimental findings. A similar remark has been made by Jitschin et al (1983) in their analysis of ionization cross section ratios for gold, which are very different from the predicted values, even when introducing intra-shell effects.…”

Section: Cross Section Valuesmentioning

confidence: 86%

“…Recently, our group has proposed a simple way to extend the relativistic calculations of Crasemann (1985, 1989), based on Dirac-Hartree-Slater (DHS) wavefunctions, to all the targets with 40 Z 2 85 at all the incident energies between 0.15 and 3.0 MeV and for all the incident ions (with Z 1 Z 2 ), as well as a way to introduce in these calculations the UA approximation (De Cesare et al 1993, 1994, leading in the end to ((E)RPWBA-BC-UA-DHS) values of the cross sections (in the following DHS-UA).…”

Section: Theoretical Modelsmentioning

confidence: 99%

Adiabatic L-shell ionization of Hg and Tl by proton and He ion impact

Cesare¹,

Murolo²,

Perillo³

et al. 1998

J. Phys. B: At. Mol. Opt. Phys.

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L-shell x-ray production cross sections by proton and 4 He ion impact on Hg and Tl (of great importance from the biological point of view, owing to their moderate toxicity properties) have been measured in the energy ranges 0.3 E p 2.6 MeV and 0.7 E4 He 1.8 MeV, respectively. L-subshell ionization cross sections have been extracted and arranged, together with the few existing data from other laboratories, in an analysis aimed at testing the performance of various theoretical approximations in the description of the ionization process. The disagreement observed at low values of the reduced velocity parameter ξ R L between the data and the predictions of the ECPSSR model is reduced significantly by using a united-atom approximation in the treatment of the binding correction, suggested by our group (ECPSSR-UA). The remaining discrepancies, mostly for the L 1 -subshell, are strongly reduced by replacing the screened hydrogen-like wavefunctions with the more realistic Dirac-Hartree-Slater ones. In the case of 4 He ions, especially for the L 2 -subshell, a more refined Coulomb deflection correction and/or more sophisticated coupled-channels calculations are also needed.

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