W W Heidbrink et al 2004 Plasma Phys. Control. Fusion 46 1855 doi:10.1088/0741-3335/46/12/005
Hydrogenic fast-ion diagnostic using Balmer-alpha light
W W Heidbrink1, K H Burrell2, Y Luo1, N A Pablant3 and E Ruskov1
Show affiliationsHydrogenic fast-ion populations are common in toroidal magnetic fusion devices, especially in devices with neutral beam injection. As the fast ions orbit around the device and pass through a neutral beam, some fast ions neutralize and emit Balmer-alpha light. The intensity of this emission is weak compared with the signals from the injected neutrals, the warm (halo) neutrals and the cold edge neutrals, but, for a favourable viewing geometry, the emission is Doppler shifted away from these bright interfering signals. Signals from fast ions are detected in the DIII-D tokamak. When the electron density exceeds ~7 × 1019 m−3, visible bremsstrahlung obscures the fast-ion signal. The intrinsic spatial resolution of the diagnostic is ~5 cm for 40 keV amu−1 fast ions. The technique is well suited for diagnosis of fast-ion populations in devices with fast-ion energies (~30 keV amu−1), minor radii (~0.6 m) and plasma densities (
1020 m−3) that are similar to those of DIII-D.
- PACS
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52.70.-m Plasma diagnostic techniques and instrumentation
- Subjects
- Dates
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Issue 12 (December 2004)
Received 30 June 2004, in final form 15 October 2004
Published 16 November 2004
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Hydrogenic fast-ion diagnostic using Balmer-alpha light
W W Heidbrink et al 2004 Plasma Phys. Control. Fusion 46 1855
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Critical behavior of a general O(n)-symmetric model of two n-vector fields in D = 4 − 2
Yuri M Pis'mak et al 2009 J. Phys. A: Math. Theor. 42 095003
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Franz Wegner 2007 J. Phys.: Condens. Matter 19 406218
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An independent brain–computer interface using covert non-spatial visual selective attention
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