Fragmentation of 200 and 244 MeV/u carbon beams in thick tissue-like absorbers

[摘要] Stacks consisting of thin CR-39 sheets sandwiched between thick lucite and water absorbers were perpendicularly bombarded by C-12 ions at 200 and 244 MeV/u. Track radius distributions representing the charge composition of the fragmented beams were automatically measured by a particle track analysis system. After analysis of the nuclear charge distributions, the total charge removal cross-sections and elemental production cross-sections of fragments with atomic numbers from 5 to 3, were obtained down to the lower energies (similar to 50 and 100 MeV/u, respectively). It has been found that the measured total charge removal cross-section agrees with theoretical predictions within -10% and very well with previous experiments in corresponding energy regions. Two model calculations for production of B fragment are in good agreement with our measured data while a third model overestimates it by similar to 12%. Theoretical cross-sections for Be and Li fragments differ strongly among the different models and from measured values. (C) 1999 Elsevier Science B.V. All rights reserved.

[发布日期] 1999-12-01

[关键词] CR-39;carbon beam;fragmentation;charge removal cross-sections