H-2(P, GAMMA)HE-3 REACTION USING POLARIZED AND UNPOLARIZED PROTONS

The 90°yield curve for the H2(p,γ)He3 reaction has been studied over the excitation region in He3 of approximately 7 to 15 MeV. Both polarized and unpolarized proton beams were used to measure the angular distributions of cross section and analyzing power at Ex=8.83, 9.83 and 10.83 MeV. If only the four non-spin-flip E 1 and E2 T-matrix elements are considered, their amplitudes and relative phases can be extracted. The E2 cross section obtained from this analysis is found to be (12±5)% of the total cross section. The detailed balanced differential (θlab=90°) and total cross sections at Ex=10.83 MeV are found to be (117±11) μb/sr and (1.07±0.11) mb, respectively; the quoted errors represent the total uncertainties in the cross sections obtained in this experiment. The results are also compared with recent E 1 and E2 calculations. NUCLEAR REACTIONS H2(p,γ)He3; measured σ(90°), Ex≅7-15 MeV; σ(θ), A(θ), and σ(tot), Ex=8.83, 9.83, and10.83 MeV; deduced E1 and E2 T-matrix amplitudes and phases. © 1979 The American Physical Society.