Photoneutron cross section forHe4

Abstract
The photoneutron cross section for He4 has been measured from threshold up to 47 MeV using monoenergetic photons and a high-pressure gas sample. The results agree with earlier monoenergetic-photon and certain photoneutron time-of-flight (liquid-sample) results at the lower energies, and consequently disagree with the results of other measurements at these energies. At the higher energies, however, the present results are essentially in agreement with all previous results.