Stopping powers of havar and effective charge for 1.4-3.2 MeV/u I-127-ions

Stopping powers of havar for 1.4-3.2 MeV/u I-127-ions have been determined by the transmission technique using two geometrical arrangements. No previo us data have been published for havar with this ion. The experimental data are compared with predictions obtained by using Bragg's additivity rule wit h various parametrizations of the stopping power found in the literature. T he values obtained by the parametrizations underestimate the experimental d ata by 5-11%. The empirical correction scheme of Thwaites yields values in rather good agreement with the present results, especially at energies abov e 1.9 MeV/u. The effective charges of the I-127 ions were also deduced from the experimental data. (C) 2000 Elsevier Science B.V. All rights reserved.