Observation of the alpha particle "Knock-On" neutron emission from magnetically confined DT fusion plasmas
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.
Kallne
J
Department of Neutron Research, Uppsala University, EURATOM-NFR Association, Uppsala, Sweden.
Ballabio
L
Frenje
J
Conroy
S
Ericsson
G
Tardocchi
M
Traneus
E
Gorini
G