The ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(p,pn){}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ reaction cross section has been measured at 800 MeV by the method of activation analysis. The value of 32.0 ± 1.0 mb is about 8% greater than the normally used interpolated value of Cumming.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(p,pn){}_{}{}^{11}{}_{}{}^{}\mathrm{C}$, measured $\sigma$ at $E_p=800\mathrm{}$ MeV.

• Received 15 March 1976

DOI:https://doi.org/10.1103/PhysRevC.14.753