title: Observation of the alpha particle "Knock-On" neutron emission from magnetically confined DT fusion plasmas
abstract: Suprathermal fuel ions from alpha-particle knock-on collisions in fusion DT plasmas are predicted to cause a weak feature in the neutron spectrum of d+t-->alpha+n. The knock-on feature has been searched for in the neutron emission of high ( >1 MW) fusion-power plasmas produced at JET and was found using a magnetic proton recoil type neutron spectrometer of high performance. Measurement and predictions agree both in absolute amplitude and in plasma-parameter dependence, supporting the interpretation and model. Moreover, the results provide input to projecting alpha-particle diagnostics for future self-heated fusion plasmas.
authors.affiliation: Department of Neutron Research, Uppsala University, EURATOM-NFR Association, Uppsala, Sweden.
authors.initials: J
authors.lastname: Kallne
authors.initials: L
authors.lastname: Ballabio
authors.initials: J
authors.lastname: Frenje
authors.initials: S
authors.lastname: Conroy
authors.initials: G
authors.lastname: Ericsson
authors.initials: M
authors.lastname: Tardocchi
authors.initials: E
authors.lastname: Traneus
authors.initials: G
authors.lastname: Gorini