Interaction of 12- to 13-Mev Neutrons with Deuterons

By use of a ${\mathrm{CD}}_4$-filled high pressure cloud chamber, the angular distribution of recoils from 12- to 13-Mev neutrons has been studied. The angular range 0° to 140° in the center-of-mass system was covered by these measurements. The distribution indicates a rather large asymmetry in the forward and backward directions with a minimum at about 60° in the center-of-mass system. The existence of a $\mathrm{D}\mathrm{}(n,2n)p$ reaction was evident by the presence of tracks between 60° and 90° in the laboratory system which were too long to be accounted for by either deuteron or proton elastic recoils.