Charge-exchange measurements of beam ion thermalization in MHD-quiescent plasmas in the Poloidal Divertor Experiment

The horizontally scanning, multiangle charge-exchange analyzer on the Poloidal Divertor Experiment (PDX) was used to study the beam ion slowing-down process with high-power perpendicular injection. Measurements were made over a wide range in toroidal field (8 kG < B(T) < 22 kG), plasma current (200 kA < I(p) < 500 kA), and beam power (1 MW < P/sub B/ < 7 MW). In MHD-quiescent plasmas, good agreement is found between the measured slowing-down spectra and theoretical predictions as a function of both angle and energy. Classes of prompt orbit losses are observed with both co- and counter-injection which have been understood and applied to plasma diagnostics. The effects of MHD activity on fast ion thermalization will be the subject of a companion paper