The Reaction D(p, γ)He3 Below 50 Kev

The yield and angular distribution of the γ rays from the reaction D(p, γ)He³ have been measured with thick heavy-ice targets in the energy range from 24 kev to 48 kev. Assuming a simplified energy dependence the results have been analyzed to give cross sections for p-wave and s-wave capture. At 25 kev in the laboratory system, the cross sections are

σ _p = (2.9±0.3)×10⁻³² cm²,

σ _s = (1.3±0.3)×10⁻³² cm².

The astrophysical S-factors in the center-of-mass system below 40 kev have been found to be

S_p = [(0.127±0.013) + 0.0079 E] ev barns

for E in center-of-mass kilovolts and

S_a = 0.12±0.03 ev barns

independent of energy giving a total S-factor for low energies

S = S_a +S_p = (0.25±0.04)+0.0079 E ev barns

with E in center-of-mass kilovolts.