Gamma-gamma coincidences following the inelastic scattering of accelerator-
produced monoenergetic neutrons have been experimentally observed. A coinci
dence system consisting of a neutron collimator and three HPGe gamma-ray de
tectors, is shown to provide important information on the isotopic identifi
cation and placement of gamma rays. The development and use of the system i
s described, and initial results are presented. (C) 1999 Elsevier Science B
.V. All rights reserved.