Measurements of 1H(d-->,γ)3He and 2H(p-->,γ)3He at very low energies
Abstract
Angular distributions of the analyzing powers iT11, T20, and T22 for 1H(d-->,γ)3He at 40<=Ec.m.<=110 keV and the angular distribution of the analyzing power Ay for 2H(p-->,γ)3He at 70<=Ec.m.<=210 keV have been measured for the first time. In addition, absolute differential cross sections for proton-deuteron capture have been determined for Ec.m.= 75, 108, 133, and 173 keV. Thick ice or heavy ice targets and two large-volume, high-purity Ge γ-ray detectors were used. Results are in general agreement with an exact three-body calculation utilizing a realistic nucleon-nucleon potential. The vector-polarization observables are found to be especially sensitive to meson-exchange-current effects. The extracted S(0) value for proton-deuteron capture is ~25% lower than that presently used in astrophysical calculations. An expression for the thermonuclear reaction rate below 10 GK is given.
- Publication:
-
Physical Review C
- Pub Date:
- February 1997
- DOI:
- 10.1103/PhysRevC.55.588
- Bibcode:
- 1997PhRvC..55..588M
- Keywords:
-
- 21.45.+v;
- 24.70.+s;
- 25.10.+s;
- 25.40.Lw;
- Few-body systems;
- Polarization phenomena in reactions;
- Nuclear reactions involving few-nucleon systems;
- Radiative capture