X-ray observations of medium Z H- and He-like ions with satellites from C-Mod tokamak plasmas

• Main Authors: Reinke, M L (Author), Ashbourn, J M A (Author), Bitter, M (Author), Delgado-Aparicio, L (Author), Hill, K (Author), Safronova, U I (Author), Rice, John E (Contributor), Gao, Chi (Contributor), Howard, Nathaniel Thomas (Contributor), Hughes Jr, Jerry (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Nuclear Science and Engineering (Contributor), Massachusetts Institute of Technology. Plasma Science and Fusion Center (Contributor)
• Format: Article
• Language: English
• Published: IOP Publishing, 2017-09-11T18:53:10Z.
• Subjects: Article
• Online Access: Get fulltext

X-ray spectra of H- and He-like ions (and satellites) from argon, calcium and chlorine have been measured in Alcator C-Mod tokamak plasmas using a high wavelength resolution imaging x-ray spectrometer system. For H-like charge states, the Lyα doublet intensity ratio is found to be slightly greater than 1/2 due to interaction with the [superscript 2]S[subscript 1/2] fine structure sub-level. Neighbouring satellites with spectator electrons occupying n = 2 through n = 7 have been modelled. The Lyα doublet ratio scalings with electron density and temperature are shown to be in good agreement with collisional-radiative modelling. For He-like ions, the n = 2 satellite intensities are in good agreement with calculations and can be used to determine the electron temperature. The high n Rydberg series has been resolved up to 1s[superscript 2]-1s14p, and satellites with spectator electrons up to the n = 12 level have been identified.
United States. Department of Energy (Contract DE-FC02-99ER54512)