Neutron transmission in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ has been estimated by analyzing ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(γ,pn) and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(γ,p) data, that were collected simultaneously using the Mainz Microtron (MAMI-A) tagged-photon system, at photon energies from 80 to 157 MeV. Correction has been made for solid angle and threshold effects by use of a Monte Carlo simulation. The corrected ratio of the (γ,pn) and (γ,p) data gives an indication of the proportion of emitted protons that have an accompanying neutron. This ratio, which can be interpreted as a lower limit for the neutron transmission in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, has been found to be 0.80±0.08 for the 20–45 MeV neutrons examined in this experiment. Since the data sets were collected simultaneously, systematic uncertainties associated with the tagger and proton detector cancel in the ratio.

• Received 15 January 1993

DOI:https://doi.org/10.1103/PhysRevC.47.2185