Enhanced production of ${}_{}{}^{24}{}_{}{}^{}\mathrm{Na}$ by wide-angle secondaries produced in the interaction of relativistic carbon ions with copper

Radiochemical activation techniques were used to study the behavior of projectile fragments formed in the interaction of 44 GeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ions within thick Cu targets. After a short review of the results obtained hitherto with this Cu-target technique, the interaction of 44 GeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ with several copper target configurations yielding the deep spallation product ${}_{}{}^{24}{}_{}{}^{}\mathrm{Na}$ is described. Energetic fragments which are emitted into the laboratory angles 10°≤θ≤45° appear to produce more ${}_{}{}^{24}{}_{}{}^{}\mathrm{Na}$ (up to nearly one order of magnitude) than calculated with a phenomenological model and an intranuclear cascade model. This enhanced production of ${}_{}{}^{24}{}_{}{}^{}\mathrm{Na}$ by wide-angle secondaries is only observed for 44 GeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ on copper, but not for 25 GeV ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ on copper. Some normalization experiments with 4 GeV ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and 2.6 GeV p are described.