Quasi-monoenergetic neutron beams with energies from 25 to 70 MeV

Quasi-monoenergetic neutron beams in the energy range from about 25 to 70 MeV have been produced and accurately characterised at the accelerator facility of the Université Catholique de Louvain (UCL), Belgium. The neutron fluence was determined with a proton recoil telescope and a liquid scintillation detector (NE213). The spectral fluence was measured employing the time-of-flight method with the NE213 detector and a 238U fission ionisation chamber. The results obtained with the different methods are in agreement within the respective uncertainties.