Relative yields of 35 products extending from ${}_{}{}^7{}_{}{}^{}\mathbf{Be}\mathbf{to}$ ${}_{}{}^{67}{}_{}{}^{}\mathrm{Ga}$ have been measured for the interaction of 25-GeV (2.1-GeV/amu) ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ions with Cu. For purposes of comparison, cross sections of 48 nuclides produced by the irradiation of Cu with 28-GeV protons are also reported. The mass yield curve deduced for the 2.1-GeV/amu ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ions is very similar to that reported for 0.28-GeV/amu ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, which implies that there is little energy dependence of target fragmentation cross sections in this energy range where meson production effects in nucleon-nucleon collisions become important. Charge dispersion curves for products with $37\le A\le 64$ are the same within errors for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and protons. Compared with 28-GeV protons, the mass yield curve for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ shows some favoring of products near the target (possibly due to increased secondary effects). Formation of light fragments such as ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^{24}{}_{}{}^{}\mathrm{Na}$ is significantly enhanced possibly due to highly damaging central collisions of the heavy ions. The results are discussed in terms of the concepts of limiting fragmentation and factorization.

NUCLEAR REACTIONS Cu(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, spallation), $E=25\mathrm{}$ GeV; measured relative $\sigma \mathrm{}(A,Z)\mathrm{}$, 35 products ${}_{}{}^7{}_{}{}^{}\mathrm{B}\mathrm{e}-$ ${}_{}{}^{67}{}_{}{}^{}\mathrm{Ga}$. Cu $p$, spallation), $E=28\mathrm{}$ GeV; measured $\sigma \mathrm{}(A,Z)\mathrm{}$, 48 products ${}_{}{}^7{}_{}{}^{}\mathrm{B}\mathrm{e}-$ ${}_{}{}^{67}{}_{}{}^{}\mathrm{Ga}$. Natural targets, Ge(Li) detectors, radiochemistry.

• Received 20 May 1976

DOI:https://doi.org/10.1103/PhysRevC.14.1554