Saturation effect in the excitation of heliumlike Si projectiles in the intermediate velocity range
| Autor: | M.B. Kurup, László Gulyás, Amal Saha, P. N. Tandon, Lokesh C. Tribedi, U. Tiwari |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | Physical Review A. 58:4494-4500 |
| ISSN: | 1094-1622 1050-2947 |
| Popis: | The saturation effect in the excitation cross sections has been investigated for ${\mathrm{Si}}^{12+}$ ions colliding with gas target atoms (atomic number ${Z}_{t}$ between 2 and 54) in the (8--12)-a.u. velocity range, both experimentally and theoretically. The experimental excitation cross sections have been deduced from the measured Ly x rays following the decay of the excited atoms. Theoretical calculations have been performed using the first Born approximation, the symmetric eikonal continuum distorted wave (SECDW) approximation, and the Schwinger variational principle (SVP). Similar to the earlier observations on the heavier ion species, the saturation has been found in both the experimental and the SVP cross sections in the entire velocity range. The SECDW approximation, however, has been found to underestimate the cross sections at large values of ${Z}_{t}$ in the presently investigated systems. In the light of these findings, the role of higher-order effects within different theoretical models has been reviewed and the possible interaction mechanisms have been discussed. |
| Databáze: | OpenAIRE |
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