The TFTR diagnostic natural beam

This paper discusses a neutral beam designed and fabricated to aid in the measurement of ion temperatures of hot, dense TFTR plasmas. The injected fast neutral atoms have a twofold advantage: penetration to the plasma center considerably increases charge exchange neutralization of thermal plasma ions, leading to a localized enhancement of the thermal neutrals efflux into charge exchange neutral analyzers (CENA); and charge exchange recombination of intrinsic impurity ions, C or O, with fast neutral allows Doppler broadening and shift measurements of the emitted light (CHERS) to determine both the impurity ion temperature and toroidal rotation with unbalanced beam heating. Those features of the beam unique to its function as a diagnostic tool and initial measurements on TFTR are presented