Radiative Capture of Deuterons byHe3

The excitation function of ${\mathrm{He}}^3(d, \gamma )$ capture radiation, measured from $E_d=0.2\mathrm{} \mathrm{to} 2.85$ Mev, exhibits a broad resonance at 0.45±0.04 Mev, with a total cross section of 0.05±0.01 mb. Above this energy, the presence of nonresonant capture is observed. At $E_d=0.58\mathrm{}$ Mev, the radiation is isotropic from 0° to 90° within ±10 percent. The measured gamma-ray energy of 16.6±0.2 Mev at resonance corresponds to a $Q$ value for the ${\mathrm{He}}^3(d, \gamma ){\mathrm{Li}}^5$ reaction of 16.36±0.2 Mev. The experimental radiation width at resonance is calculated to be 11±2 ev, which is compared to the Weisskopf estimate for $E1\mathrm{}$ transitions.