RF-driven Energetic Tritium Ion Tail Measurements in TFTR Using the Pellet Charge Exchange Diagnostic
Authors: H.H. Duong, R.K. Fisher, J.M. McChesney, P.B. Parks, et al
Charge exchange interactions of ions with the ablation cloud of an injected low-Z impurity pellet can be used to measure the energy spectrum and radial profile of confined fast ions in a fusion plasma. On TFTR, we use this technique to directly measure energetic alphas from D-T reactions, tritons from D-D reactions, and RF-driven minority tail ions (e.g., H, 3He, T). This paper describes the status of the Pellet Charge Exchange (PCX) diagnostic including a brief description of the measurement technique and discussion of operational experience. PCX measurements of the energy spectrum, radial density distribution, and heating deposition profile of RF-driven tritium ions during 2WT heating of L-mode plasmas are presented.