title: In-vessel activation monitors in JET: progress in modeling.
abstract: Activation studies were performed in JET with new in-vessel activation monitors. Though primarily dedicated to R&D in the challenging issue of lost diagnostics for ITER, which is being addressed at JET with several techniques, these monitors provide for both neutron and charged particle fluences. A set of samples with different orientation with respect to the magnetic field is transported inside the torus by means of a manipulator arm (in contrast with the conventional JET activation system with pneumatic transport system). In this case, radionuclides with longer half-life were selected and ultralow background gamma-ray measurements were needed. The irradiation was closer to the plasma and this potentially reduces the neutron scattering problem. This approach could also be of interest for ITER, where the calibration methods have yet to be developed. The MCNP neutron transport model for JET was modified to include the activation probe and so provide calculations to help assess the new data. The neutron induced activity on the samples are well reproduced by the calculations.
authors.affiliation: Laboratory for Plasma Physics, Association Euratom-Belgian State, Avenue de la Renaissance 30, B-1000 Brussels, Belgium.
authors.forename: Georges
authors.initials: G
authors.lastname: Bonheure
authors.forename: I
authors.initials: I
authors.lastname: Lengar
authors.forename: B
authors.initials: B
authors.lastname: Syme
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Wieslander
authors.forename: Mikael
authors.initials: M
authors.lastname: Hult
authors.forename: Joël
authors.initials: J
authors.lastname: Gasparro
authors.forename: Gerd
authors.initials: G
authors.lastname: Marissens
authors.forename: Dirk
authors.initials: D
authors.lastname: Arnold
authors.forename: Matthias
authors.initials: M
authors.lastname: Laubenstein
authors.forename: S
authors.initials: S
authors.lastname: Popovichev