Time-of-Flight Spectrometer for the Measurement of Gamma Correlated Neutron Spectra

A time-of-flight spectrometer for the measurement of gamma correlated neutron spectra from (n,xnJ;) reactions is described. The operation and the main parameters are discussed. The resolution in the neutron channel is 2.2 ns/m at the 150 keV neutron energy threshold. A simultaneous measurement of the time-of-flight and amplitude distributions makes it possible to study gamma correlated neutron spectra as well as the prompt gamma spectra in coincidence with selected energy neutrons. In order to test the spectrometer, measurements of the neutron spectrum in coincidence with the 845 keV gamma line of 56Fe were carried out at an incident neutron energy of 14.1 MeV.