Evaluation of excited nl-state distributions of fast exit ions after penetrating through solid foils. Part 2: Determination of the nl-state distribution fractions of exit ions

In Part 1 (T. Miyoshi, K. Noda, Y. Sato, H. Tawara, I.Yu. Tolstikhina, V.P. Shevelko, Nucl. Instr. and Meth. B, this issue) of our two reports, new experimental data on charge-state evolution Fq(D) and equilibrium fractions Fq(Infinite) were presented when 4.3 MeV/u projectile ions with the atomic number Z = 6-6 pass through carbon. Also, in this paper, a ten-charge-state model for equilibrium fractions Fq(Infinite) expressed in terms of the charge-changing cross sections was suggested. In the present work (Part 2), a new method is suggested to determine the nl-distributions Nq(nl) of exit ions with a charge q in the specific nl-states by solving the balance equations with all appropriate effective cross sections as coefficients. The Fq(Infinite) and Nq(nl) values are normalized so that Sum (Fq(Infinite)) = 1 and Sum (Nq(nl)) = Fq(Infinite). The efficiency of the present method suggested is illustrated by example of Ar ions colliding with a carbon foil at projectile energy of E = 6.0 MeV/u. It is found that the exit argon beam comprises about 12% of argon ions in the excited states. This method can be used for evaluation of the excited-ion components in the exit ion beam when the charge equilibrium has been reached. Besides, in this work, extending the method described in (Miyoshi et al., this issue), evaluation of nl-state distributions of exit ions at energies E = 4-20 MeV/u is performed for the case of Ar + C foil collisions, therefore, allowing to observe the nl-state distributions in a wide energy range