Characterization of neutron elastic recoil detection analysis with low-energy neutron beams

The applicability of a low-energy neutron beam for neutron elastic recoil detection (NERD) has been studied. With this objective, we have constructed a compact gas counter consisting of a gridded ionization chamber and a solid-state detector (SSD) to detect and distinguish the low-energy species elastically recoiled by the neutron beam. By using the 241Am-α source, the optimum parameter set of this gas counter, i.e., the ratio of electric field to gas pressure, has been determined. In the NERD experiment using this gas counter with the optimum parameters, the energy distributions of hydrogen emitted from the polyethylene and Mylar sample targets by the neutron beam coming from the reaction 7Li(p, n)7Be were measured and compared with theoretical calculations. It has been shown that the NERD using the low-energy neutron beam can be a useful, noncontaminating technique for analyzing light species from materials. (author)