Total charge-changing and partial cross-section measurements in the reactions of∼110–250 MeV/nucleon 12Cin carbon, paraffin, and water

Abstract

Total charge-changing cross sections and cross sections for the production of B and Be fragments were directly measured for reactions induced by $\ensuremath{\sim}110--250 \mathrm{M}\mathrm{e}\mathrm{V}/\mathrm{n}\mathrm{u}\mathrm{c}\mathrm{l}\mathrm{e}\mathrm{o}\mathrm{n}{ }^{12}\mathrm{C}$ ions in C, ${\mathrm{CH}}_{2},$ and ${\mathrm{H}}_{2}\mathrm{O}$ targets. Etched track detector (CR-3) was used, together with an automatic track measuring system and a track matching algorithm, to count and to identify the primary and secondary particles. A comparison of the present data and of previously measured cross sections with model predictions is carried out. For the total charge-changing cross section, a model developed at NASA gives the best agreement with the present results (about 3% on the average). However, for the production of fragments, the results of models deviate on average for all systems studied by 9--58 % from the data presented in this work for $Z=5$ and by 5--47 % for $Z=4.$ The model known as NUCFRG2 is the most reliable in giving the closest values for fragmentation cross sections, 9 and 5% for B and Be fragments, respectively, for the systems studied in this work.