Neutron Polarization in thed+T→n+He4Reaction at 30° from 3 to 15 MeV

Abstract

An experimental study has been made of neutron polarization from the $\mathrm{T}\mathrm{}(d,n)\mathrm{}{}_{}{}^4{}_{}{}^{}\mathrm{He}$ reaction at 30° lab as a function of incident deuteron energy. A liquid-helium polarimeter was employed for this purpose with a 90° spin-precession solenoid. Measurements have been made in two ways, with greatest emphasis placed on the use of the backward reaction, $\mathrm{D}\mathrm{}(t,n)\mathrm{}{}_{}{}^4{}_{}{}^{}\mathrm{He}$, for a range of triton energies between 4.5 and 19.5 MeV. Equivalent c.m. conditions are obtained for $E_t=\frac{3}{2}{E}_d$, with neutrons emerging in the vicinity of 135° lab. Under these conditions, the neutron energy is near 11 MeV over a wide range of triton energies, where the $n-\mathrm{H}\mathrm{e}$ analyzing power is constant and well known. Measurements were also made from the $\mathrm{T}\mathrm{}(d,n)\mathrm{}{}_{}{}^4{}_{}{}^{}\mathrm{He}$ reaction directly at 30° for a range of deuteron energies between 5 and 15 MeV. The measured polarizations varied from 0.03 at 3-MeV to 0.69 at 13-MeV equivalent deuteron energy. Comparisons are made with prior data. The method also allows extraction of values of the $n-\mathrm{H}\mathrm{e}$ analyzing power for neutron energies between 21 and 29 MeV at 75 and 113° lab.