Neutron spectrum of a Ra\u2013Be(\u3b1, n) source

The neutron energy spectrum of a Ra\u2013Be source has been measured successfully by the nuclear emulsion technique without introducing a significant thickness of lead absorber to reduce the \u3b3-ray background. In comparison with the spectra published by other authors, the part of the spectrum below 4\u2002Mev is found to be somewhat less intense, probably owing to the absence of inelastic scattering in the lead. No observations could be made below 0.75\u2002Mev; however, by comparison with the source emission rate, it was estimated that this fraction of the spectrum contributes (37\u2002\ub1\u200215)% of the total neutron emission.Authors were affiliated with the NRC Division of Applied Physics at time of publicationNRC publication: Ye