Radiative Capture of Tensor and Vector Polarized Deuterons by Tritium at 8.6 Mev and 400 KEV

The ^3H(d,gamma )^5He reaction was studied at 8.6 MeV and 400 keV using polarized and unpolarized beams to deduce the relative strengths of the S = 3/2 and S = 1/2 channels. The absolute differential cross section sigma(theta), A_{rm y}( theta), and T_{20} (theta) were measured at E _{rm d} = 8.6 MeV and the differential cross section sigma (theta), A_ {rm y}(theta), and A_{rm yy}( theta) were measured at 400 keV. The a_{rm k}, b_{rm k}, and c _{rm k} coefficients of Legendre polynomial expansions of the observables were extracted at both energies. A T-matrix analysis of the E_{rm d} = 400keV data indicates 95% S = 3/2 (E1) strength, with 2.5% S = 1/2 (E1) and 2.5% M1 strength present. A direct capture E1 calculation was performed at 8.6 MeV and was in good agreement with the experimentally determined coefficients when a spin-orbit interaction was included. The results of this comparison indicated that the ground state of ^5He consisted of 88-100% S = 3/2 strength. This result was also consistent with the 95% S = 3/2 (E1) strength found by the T-matrix analysis of the low energy data.