A spatially resolving x-ray crystal spectrometer for measurement of ion-temperature and rotation-velocity profiles on the Alcator C-Mod tokamak

K W Hill; M L Bitter; S D Scott; A Ince-Cushman; M Reinke; J E Rice; P Beiersdorfer; M-F Gu; S G Lee; Ch Broennimann; E F Eikenberry

doi:10.1063/1.2969080

A spatially resolving x-ray crystal spectrometer for measurement of ion-temperature and rotation-velocity profiles on the Alcator C-Mod tokamak

Rev Sci Instrum. 2008 Oct;79(10):10E320. doi: 10.1063/1.2969080.

Authors

K W Hill¹, M L Bitter, S D Scott, A Ince-Cushman, M Reinke, J E Rice, P Beiersdorfer, M-F Gu, S G Lee, Ch Broennimann, E F Eikenberry

Affiliation

¹ PPPL, Princeton University, P.O. Box 451, Princeton, New Jersey 08543, USA.

PMID: 19044482
DOI: 10.1063/1.2969080

Abstract

A new spatially resolving x-ray crystal spectrometer capable of measuring continuous spatial profiles of high resolution spectra (lambda/d lambda>6000) of He-like and H-like Ar K alpha lines with good spatial (approximately 1 cm) and temporal (approximately 10 ms) resolutions has been installed on the Alcator C-Mod tokamak. Two spherically bent crystals image the spectra onto four two-dimensional Pilatus II pixel detectors. Tomographic inversion enables inference of local line emissivity, ion temperature (T(i)), and toroidal plasma rotation velocity (upsilon(phi)) from the line Doppler widths and shifts. The data analysis techniques, T(i) and upsilon(phi) profiles, analysis of fusion-neutron background, and predictions of performance on other tokamaks, including ITER, will be presented.