Determination of the Energy and Momentum of Fast Neutrons in Cosmic Rays

PREVIOUS experimenters, working on the multiple disintegration phenomena produced by cosmic radiations, have concluded that some at least of the nuclear explosions are produced by fast neutrons. In approaching the problem of determining the energy of such neutrons, we meet the difficulty that the usual method, in which observations are made on the recoil protons which the neutrons produce by collision with hydrogen nuclei, is not applicable. It is therefore important to develop alternative methods, and, for this purpose, we have examined the possibility of employing the nuclear reaction between boron and fast neutrons.