14 MeV neutron spectra measurements using type IIa diamond detectors

Natural diamond detectors have been used as a neutron spectrometer to measure 14 MeV neutron spectra produced by a neutron generator. The spectrometer chain was energy calibrated with a Am-241 alpha source and a precision pulser. The different reactions between diamond and neutrons were identified and the C-12(n,alpha(0))Be-9 reaction was used to measure the neutron spectra. The C-12(n,alpha(0))Be-9 reaction produces a peak in the purse-height spectrum at energy E(n) of 5.7 MeV, where E(n) is the incident neutron energy. The neutron energy E(n) measured had a resolution ranging between 3 and 7%, depending on the detector tested, thus showing that diamond detectors could be used as spectrometers for monoenergetic neutrons. The comparison of the experimental and the theoretical detection efficiency is discussed.