The measurement of the fast neutron energy spectrum by using a He-3 proportional counter and the time- of-flight technique

In this study an attempt has been made to measure the fast neutron energy spectrum from the ''9Be(3He,n)''1''1C reaction. The fast neutrons are produced by bombarding 3 mn thick Beryllium target with 30 MeV He-3 ions from the 1.52 m Nuffield cyclotron. For the measurement of neutrons spectra, a He-3 proportional counter and the time-of-flight technique have been used. It was found that the neutrons at 0''0 have a continuous distribution of energy as up to about 36.5 MeV