The angular distribution of the charged particles produced in the bombardment of ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$ by 14-Mev neutrons was observed with nuclear emulsions in a multiplate camera. Metallic targets of enriched ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$ were used. The following cross sections were measured: ${\mathrm{Li}}^6(n, p){\mathrm{He}}^6$, 6±2 mb; ${\mathrm{Li}}^6(n, d){\mathrm{He}}^5$, 89±10 mb; ${\mathrm{Li}}^6(n, d){\mathrm{He}}^{5*}$, 77±9 mb; ${\mathrm{Li}}^6(n, t){\mathrm{He}}^4$, 26±4 mb; ${\mathrm{Li}}^7(n, t){\mathrm{He}}^5$, 55±8 mb. The reaction ${\mathrm{Li}}^7(n, d){\mathrm{He}}^6$ was also observed but was not well enough resolved to give an angular distribution and total cross section. No evidence was found for the formation of ${\mathrm{He}}^7$ by ${\mathrm{Li}}^7(n, p){\mathrm{He}}^7$ with a cross section greater than 5 mb in the range $-1.0>Q>-7.0\mathrm{}$ Mev. The angular distributions obtained for ${\mathrm{Li}}^6(n, d){\mathrm{He}}^5$ and ${\mathrm{Li}}^6(n, d){\mathrm{He}}^{5*}$ indicate these reactions proceed mainly by an inverse stripping or pick-up process. The energy spectrum of the neutrons from ${\mathrm{Li}}^6(n, d){\mathrm{He}}^5\mathrm{}\left(n\right)\mathrm{}{\mathrm{He}}^4$ and ${\mathrm{Li}}^6(n, d){\mathrm{He}}^{5*}\mathrm{}\left(n\right)\mathrm{}{\mathrm{He}}^4$ is calculated using several assumptions for the angular distribution of the ${\mathrm{He}}^5$ disintegration.

• Received 24 November 1953

DOI:https://doi.org/10.1103/PhysRev.93.1086