title: Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer.
abstract: The fuel ion ratio nt/nd is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., nt/nd = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands that a DT spectrometer has to fulfill to be able to determine nt/nd with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Hellesen
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Skiba
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: N
authors.initials: N
authors.lastname: Dzysiuk
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Weiszflog
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Hjalmarsson
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Ericsson
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Conroy
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Andersson-Sundén
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Eriksson
authors.affiliation: Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala, Sweden.
authors.forename: F
authors.initials: F
authors.lastname: Binda