A 4 pi BaF2 detector for (n,gamma) cross-section measurements at a spallation neutron source

The quest for improved neutron capture cross-sections for advanced reactor concepts, transmutation of radioactive wastes as well as for astrophysical scenarios of neutron capture nucleosynthesis has motivated new experimental efforts based on modern techniques. Recent measurements in the keV region have shown that a 4 pi BaF2 detector represents an accurate and versatile i nstrument for such studies. The present work deals with the potential of su ch a 4 pi BaF2 detector in combination with spallation neutron sources, whi ch offer large neutron fluxes over a wide energy range. Detailed Monte Carl o simulations with the GEANT package have been performed to investigate the critical backgrounds at a spallation facility, to optimize the detector de sign, and to discuss alternative solutions. (C) 2001 Elsevier Science B.V. All rights reserved.