Layout And Results From The Initial Opeeration Of The High-resolution X-ray Imaging Crystal Spectrometer On The Large Helical Device
Authors: N.A. Pablant, M. Bitter, L. Delgado-Apricio, M. Goto, K.W. Hill, S. Lazerson, S. Morita, A.L. Roquemore, D. Gates, D. Monticello, H. Neilson, A. Reiman, M. Reinke, J.E. Rice and H. Yamada
Abstract:
First results of ion and electron temperature pro le measurements from the x-ray
imaging crystal spectrometer (XICS) diagnostic on the Large Helical Device (LHD)
are presented. This diagnostic system has been operational since the beginning of the
2011 LHD experimental campaign and is the rst application of the XICS diagnostic
technique to helical plasma geometry. The XICS diagnostic provides measurements
of ion and electron temperature pro les in LHD with a spatial resolution of 2cm
and a time resolution of ≥ 10ms. Ion temperature pro les from the XICS diagnostic
are possible under conditions where charge exchange recombination spectroscopy
(CXRS) is not possible (high density) or is perturbative to the plasma (low density
or radio frequency heated plasmas). Measurements are made by using a spherically
bent crystal to provide a spectrally resolved 1D image of the plasma from line integrated
emission of helium-like Ar16+. The nal hardware design and con guration are
detailed along with the calibration procedures. Line-integrated ion and electron temperature
measurements are presented, and the measurement accuracy is discussed.
Finally central temperature measurements from the XICS system are compared to
measurements from the Thomson scattering and CXRS systems, showing excellent
agreement.
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Submitted to: Review of Scientific Instruments (March 2012)
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Download PPPL-4750 (pdf 12 MB 22 pp)
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