5. Theoretical Physics (CSN4)

The rainbow ion-solid interaction potential

by Srdan Petrović (Vinca Inst. of Nuclear Inst.)

Europe/Rome
Aula Seminari (LNF)

Aula Seminari

LNF

Via Enrico Fermi, 40 00044 Frascati (Roma)
Description
This talk will be devoted to the rainbow proton-silicon interaction potential. We show that it can be obtained as a modification of the corresponding Molière proton-silicon interaction potential by applying the theory of crystal rainbows [1] and the experimental high-resolution angular pattern of 2 MeV protons transmitted through a 55 nm thick <100> Si crystal [2]. The fitting procedure has been performed so that the peripheral rainbow line, generated by the corresponding ZBL interaction potential [3], and the central rainbow line, generated by the Molière interaction potential used by Krause et al. [4], were at the same time well approximated by the rainbow lines generated by the rainbow interaction potential. As a result, the theoretical angular distributions of transmitted protons are in excellent agreement with the corresponding experimental ones. Possible applications of the rainbow ion–atom interaction potential has been discussed. [1] S. Petrović, L. Miletić, and N. Nešković, Theory of rainbows in thin crystals: The explanation of ion channeling applied to Ne10+ ions transmitted through a <100> thin crystal, Phys. Rev. B 61, 184 (2000). [2] M. Motapothula, S. Petrović, N. Nešković, Z. Y. Dang, M. B. H. Breese, M. A. Rana, and A. Osman, Origin of ringlike angular distributions observed in rainbow channeling in ultrathin crystals, Phys. Rev. B 86, 205426 (2012). [3] J. F. Ziegler, J. P. Biersack and U. Littmark, The stopping and range of ions in solids (Pergamon Press, 1985). [4] H. F. Krause, J. H. Barrett, S. Datz, P. F. Dittner, N. L. Jones, J. Gomez del Campo, and C. R. Vane, Angular distribution of ions axially channeled in a very thin crystal: Experimental and theoretical results, Phys. Rev. A 49, 283 (1994).