Plasma rotation measurements in NCSX using x-ray spectroscopy

1
Plasma rotation measurements in NCSX using x-ray
spectroscopy
R. Granetz and J. Rice
NCSX research forum 7-8 Dec 2006
2
Why are we interested in doing this?

• Crucial test of QAS Rotation is a relatively
  simple thing to measure (as compared to
  confinement), and therefore should be studied as
  soon as possible in FY11.
• Dont have to wait for DNB/CHERS High-resolution
  x-ray spectroscopy should be easy to install,
  although spatial resolution will not be as good
  as CHERS.
• Plasmas might even rotate without NBI
• Add stellarator information to tokamak rotation
  database, hopefully improving our understanding
  of momentum physics.

3
Scaling of intrinsic rotation from multiple
tokamaks suggests scaling to ITER
4
Current PPPL/C-Mod collaboration on X-ray
spectroscopy

• Core
• H He-like argon (using curved crystal and 2-D
  detector) to measure Ti and Vi in core M.
  Bitter, K. Hill, J. Rice, A. Ince-Cushman
• Edge
• He-like neon (Ti and Vi in outer radii of plasma)
  M. Bitter, J. Rice, A. Ince-Cushman

5
NESOXS

• NEon SOft X-ray Spectrometer
• Spatially resolving spherically bent high
  resolution spectrometer looking at He-like Neon
  in the pedestal region of the plasma.
• Provides impurity poloidal rotation profiles for
  0.8 lt r/a lt0.95

6
HIREX SR

• HIgh REsolution X-ray spectrometer - Spatially
  Resolving
• Spatially resolving spherically bent crystal
  spectrometer looking at H He-like Argon
• Provides impurity temperature and rotation
  profiles for r/a lt 0.8

7
Some details

• The new 2-D HIREX on C-Mod replaces 5
  single-chord HIREX systems. One or more of these
  single-chord systems could be installed on NCSX
  (core rotation). Should be relatively
  inexpensive to do this. Might also be possible
  to duplicate the 2-D HIREX system (more expensive
  option).
• Might also be possible to duplicate the NESOX
  system (edge rotation)
• Would need
• to puff small amounts of argon into plasma
• Te 1-2 keV
• A pair of toroidally-opposing views would avoid
  the necessity of an absolute wavelength
  calibration