Charge-exchange-produced K-shell x-ray emission from Ar16+ in a tokamak plasma with neutral-beam injection -: art. no. 032725

High-resolution spectroscopy of a hot tokamak plasma seeded with argon ions and interacting with an energetic, short-pulse neutral hydrogen beam was used to obtain a high-resolution K-shell x-ray spectrum formed solely by charge exchange. The observed K-shell emission of Ar16+ is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating charge-exchange cross sections.