Impurity radiation in DITE during neutral injection

Abstract
The large increase in radiation during neutral injection in DITE is identified as being primarily due to the charge-exchange recombination of the impurities on the fast neutrals. The time dependence of the increase in line eion and its dependence on injection power and plasma density is shown to fit the theory. – The line emission and the total radiated power are found to be toroidally asymmetric, being larger in the region of beam deposition. A theoretical explanation for this asymmetry is given. The recombination of impurities by thermal neutrals is found to be important in low-density Ohmic discharges, and the implications of this are discussed.