Neutron emission Doppler-shift measurements in deuterium-tritium plasmas

Spectrometry of the neutron emission is discussed as a probe of the fuel io n velocity distribution in tokamak plasmas where the instrumental energy ca libration allows determination of Doppler shifts on an absolute scale or re lative to the emission of thermal plasma conditions. Such Doppler shifts ha ve been measured for plasmas of different heating methods at the Joint Euro pean Torus (JET) using a neutron spectrometer of the magnetic proton recoil (MPR) type. The principles of the MPR spectrometer as a rotation diagnosti c are discussed together with the results obtained for the JET plasmas. The development potential of neutron spectrometry as a rotation diagnostic at the accuracy level of +/-1 km/s for toroidal and poloidal rotation is proje cted, especially, for use on burning plasma tokamaks. (C) 1999 American Ins titute of Physics. [S0034-6748(99)59301-5].