Mass resolving charge-exchange system on the poloidal divertor experiment

Abstract

The charge-exchange system used on the Poloidal Divertor Experiment is comprised of four, ten-channel, mass-resolved, charge-exchange analyzers. Each analyzer is constructed with parallel electric and magnetic fields and is calibrated over an energy range of 0.5–40 keV. The mass rejection between hydrogen and deuterium has been measured as better than 1000 to 1. For Ohmic heated discharges the system can provide single shot radial ion temperature profiles (four point) with 1-ms time resolution. For neutral beam heated discharges, complete radial and temporal profiles can be obtained in two to four shots. The system is also equipped with a vertically aimed diagnostic neutral beam to allow local ion-energy distribution measurements. This report describes the analyzer system and its calibration, and presents results from Ohmic and neutral beam heated discharges.