Investigation of the Deuteron-Deuteron Reaction

The excitation curve for the reaction ${\mathrm{D}}^2+{\mathrm{D}}^2\to {\mathrm{He}}^3+n^1$ has been measured from 40 up to 300 kv. The yield of fast neutrons measured in the forward direction from a thick ${\mathrm{D}}_3$P${\mathrm{O}}_4$ target bombarded by 100 kv deuterons is equivalent to 44 mc of radium-beryllium per microampere. The number of neutrons observed in the forward direction (estimated from the number of recoils produced in air) corresponds to 8.7×${10}^4$ neutrons per second per μa at 100 kv over the entire solid angle if isotropic emission is assumed. However, there is a definite preponderance in the forward direction. The increase of "$C$" neutrons with the increasing thicknesses of paraffin surrounding the neutron source and the neutron detector has been measured for both the D-D neutrons and the Ra-Be neutrons. The two such curves correspond for thicknesses of paraffin greater than 5 cm. With less paraffin, relatively more neutrons are observed from the Ra-Be source. The yield of "$C$" neutrons from a ${\mathrm{D}}_3$P${\mathrm{O}}_4$ target bombarded by 1 μa of 100 kv deuterons is equivalent to that of 15 mC of radium-beryllium, but the yield is very sensitive to the geometrical arrangement of the paraffin surrounding the target. The excitation curve of the reaction ${\mathrm{D}}^2$+${\mathrm{D}}^2$→${\mathrm{H}}^1$+${\mathrm{H}}^3$ coincides with that of the alternative reaction for the energy range measured (45-100 kv). The absolute yield of protons, after correcting for the stopping power of the target, is one proton for 6×${10}^6$ deuterons, no correction being made for anisotropy of emission. This agrees within a factor of two within the neutron yield. No resonance was found in either excitation curve.