Characterization of a 40-90 MeV Li-7(p,n) neutron source at TIARA using a proton recoil telescope and a TOF method

The intensity and energy spectra of a quasi-monoenergetic Li-7(p,n) neutron source at TIARA of Japan Atomic Energy Research Institute (JAERI) have bee n measured for eight incident proton energies between 43 and 87 MeV, using a proton recoil telescope (PRT) of annular geometry and a time-of-flight (T OF) method employing organic scintillators (BC501A, NE213) calibrated prior to the experiment. By combining the two data, we deduced energy spectra of the source neutrons absolutely down to a few MeV, and the cross section of the peak neutron production reaction, Li-7(p,n(0,1))Be-7. The continuum co mponent of the energy spectrum in the source proved to be described consist ently by assuming a three-body phase-space distribution corresponding to th e Li-7(p,n(3)He)alpha reaction as a main component. The annular PRT achieve d a good compromise between energy resolution and detection efficiency with a good signal-to-noise ratio. (C) 1999 Elsevier Science B.V. All rights re served.