An investigation of the neutrons produced in the deuteron-deuteron reaction

Some properties of the 21H + 21H = 2He+10n reaction are investigated by the photographic plate technique for a bombarding deuteron energy of 920 keV. Thick deuterium targets only are used, and the following quantities measured : (a) The Q value—found to be (3·23 ± 0·02) MeV. (b) The neutron spectra at various angles of neutron emission. (c) The angular distribution of the neutrons. The problems arising in the application of the technique to the precision determination of neutron energy are discussed and the previous precision determination of the Q value by Bonner is criticized. The present results are in good agreement with the Q value of the reaction 21H + 21H = 31H + 11H and the maximum energy of the 31H β-spectrum. The neutron spectra are in accord with those calculated from the ballistics of the reaction and the known excitation function. The neutron angular distribution shows a marked maximum in the forward direction and a minimum at 90° to the deuteron beam.