Neutron detector array for measurement of neutron multiplicity

An array consisting of six neutron detectors has been constructed for measurement of neutron multiplicities in heavy ion reactions. The measurements are reported to demonstrate that, even with a modest array of six neutron detectors, it is possible to infer unambiguously the neutron multiplicity (upto M"4) of the reaction channel from the neutron fold distribution obtained in coincidence with c-rays, if the array is calibrated with known reaction channels. The neutron multiplicity for the 991 keV c-ray produced in the two heavy ion reactions 133Cs(12,13C, xn) has been determined from this set-up-indicating that it deexcites levels in 142Pm. This is in agreement with the excitation function measurements for the same reactions. ( 2000 Elsevier Science B.V. All rights reserved.