The Relative Probabilities and Absolute Cross Sections of the D — D Reactions

Measurements with a gas target have been made of the relative probabilities and absolute cross sections of the two possible D --- D reactions, by simultaneously counting the helium and hydrogen nuclei produced by the reactions. The counters were separated from the target by a thin silica window. The ratio of the cross section of the neutron-producing reaction to that of the proton-producing reaction was found to increase from 0. 95 at 120 kev to 1. 06 at 250 kev. The "neutron" cross section was 0. 019 barn at 120 kev and 0. 038 barn at 250 kev while the "proton" cross section increased from 0. 020 barn at 120 kev to 0. 049 barn at 300 kev. The results can be fitted to an expression of the form =a₋P₋ and the values of the coefficients a₋ are given.