The ${}_{}{}^2{}_{}{}^{}$H(n,γ${)}^3$H reaction has been studied with polarized and unpolarized neutrons of energies ranging from 9 to 14 MeV. Angular distributions of cross section were measured at $E_{\mathrm{n}}$(lab)=9.0, 10.8, and 14.0 MeV, σ(90°) was measured at 6.85 MeV, and an analyzing-power angular distribution was measured at 9.0 MeV. The results for σ(theta) agree with the existing ${}_{}{}^3{}_{}{}^{}\mathrm{H}$(γ,n${)}^2$H data after detailed balancing. The resulting ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(γ,p)${/}^3$H(γ,n) ratio for 90° cross sections is 1.1±0.15 down to $E_x$=10.8 MeV. The T-matrix analysis of the data indicates ∼3% for the E2 contribution to the capture cross section—comparable to that found earlier for ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(p,γ${)}^3$He and in contrast to the predictions [${\sigma }_{\mathrm{n}\left(\mathrm{E}2\right)/{\sigma }_{\mathrm{p}\left(\mathrm{E}2\right)}}$=1/25] of a two-body direct-capture calculation.

• Received 5 February 1986

DOI:https://doi.org/10.1103/PhysRevC.34.389