Photon spectra in NPL standard monoenergetic neutron fields

Abstract A High Purity Germanium (HPGe) detector has been used to measure the photon spectra in the majority of monoenergetic neutron fields produced at NPL (0.144, 0.250, 0.565, 2.0, 5.0 and 16.5 MeV). The HPGe was characterised and then modelled to produce a response matrix. The measured pulse height spectra were then unfolded to produce photon fluence spectra. The new spectra were used to improve the photon to neutron dose equivalent ratios from some earlier work at NPL with Geiger–Muller tubes and electronic personal dosemeters.