Neutron energy spectrum determination near the surface of the JET vacuum vessel using the multifoil activation technique

The activation of zinc, indium, aluminum, copper and magnesium foils has been used as a means of examining the energy spectrum of neutrons produced by discharges in the Joint European Torus (JET). Several threshold reactions are used together with a least-squares unfolding code to determine the 2.5 and 14 MeV neutron yields produced by the JET plasma; the analysis shows that the energy spectrum produced by downscattered neutrons is satisfactorily calculated with the MCNP neutron transport code.<>