Observations of Recombination Population ofn=2Excited States ofAr16+in Tokamak Plasmas

Abstract
Results from the first radial measurements of the n=2 to n=1 x-ray transitions of high-Z elements in deuterium tokamak plasmas are presented. The observed line intensity ratios cannot be explained by electron-impact excitation and dielectronic recombination processes. Radiative and charge-transfer recombination are proposed as additional population mechanisms. The emission lines emitted in the cascade following capture constitute a unique diagnostic probe of the neutral component of plasmas.