Momentum transfer in the fragmentation of Cu by relativistic heavy ions and protons

Abstract

Mean kinetic properties of selected products from the fragmentation of Cu by $^{1}\mathrm{H}$, $^{4}\mathrm{He}$, and $^{12}\mathrm{C}$ ions over energies ranging from 0.18 to 28 GeV/nucleon have been determined by the thick-target, thick-catcher technique. Momentum transfer, as inferred from $\frac{F}{B}$ ratios, is observed to occur most efficiently for the lower velocity projectiles. Recoil properties of the target fragments, analyzed using the two step velocity vector model, vary strongly with product mass. Rapidity (or some other velocity related parameter) is the dominant projectile variable which governs momentum transfers to fragments from Cu. This and previous observations of the importance of kinetic energy in determining fragment yields are shown to be consistent with a simple kinematical model for the fragmentation process. Major deviations from such simple behavior are observed for high-energy heavy ions incident on heavy element targets.NUCLEAR REACTIONS Cu fragmentation by $^{1}\mathrm{H}$, $^{4}\mathrm{He}$, and $^{12}\mathrm{C}$, $\frac{T}{A}=0.18 \mathrm{to} 28$ GeV/nucleon, thick target, thick catchers; measured $\mathrm{FW}$, $\mathrm{BW}$, and $\mathrm{PW}$ for six selected products: $^{24}\mathrm{Na}$ to $^{58}\mathrm{Co}$, deduced mean kinetic properties, natural targets, Ge(Li) detectors.