Nuclear and nuclear astrophysical interest in D(n,γ)3H reaction

A neutron capture cross section of deuterium was measured for the first time at the neutron energies between 10 and 80 keV by detecting the prompt γ-ray from the capture state to the ground state of triton. The cross section is important to study the nuclear dynamics of the few nucleon systems, and to estimate the elemental abundances in the primordial nucleosynthesis. In order to pick up the small γ-ray signal from huge background we have developed highly sensitive NaI(T1) detector systems with good signal to noise ratio. Use of these detectors together with pulsed neutron beams enabled us to determine the small capture cross section accurately. The cross sections were obtained as 2.12 (35) and 2.04 (3) μbarns at 30.5 and 54.2 keV, respectively, and they are compared with the theoretical ones.