Neutron detection efficiency for the measurement of the 2H(e,′en) 1H cross section

Abstract We report a measurement of the neutron detection efficiency for an array of neutron detectors behind a lead-steel wall consisting of 10.16 cm thick lead bricks sandwiched between 3.18 cm steel plates. The neutron detection efficiency e was obtained from the ratio of coincidence to single-arm proton cross sections using the γ + 2 1 H → p + n reaction. Knowledge of the neutron detection efficiency was necessary to extract the cross section for the exclusive 2 H(e,′e n) 1 H reaction, which we used to obtain the elastic magnetic form factor G M n of the neutron. The measurements for three different neutron energies were carried out at the MIT-Bates Linear Accelerator Center with an incident electron beam energy of 254 MeV.