Temperature and density characteristics of the Helicity Injected Torus-II spherical tokamak indicating closed flux sustainment using coaxial helicity injection

Journal Article · Fri Aug 15 04:00:00 EDT 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2968205· OSTI ID:21120515

Hamp, W T; Jarboe, T R; Nelson, B A; O'Neill, R G; Raman, R; Redd, A J; Stewart, B T ^[1]; Mueller, D ^[2]

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1. University of Washington, Box 352250, Seattle, Washington 98195-2250 (United States)
2. Princeton Plasma Physics Laboratory, Princeton University, P.O. Box 453, Princeton, New Jersey 08543 (United States)

The electron temperature and density profiles of plasmas in the Helicity Injected Torus [HIT-II: T. R. Jarboe et al., Phys. Plasmas 5, 1807 (1998)] experiment are measured by multipoint Thomson scattering (MPTS). The HIT-II device is a small low-aspect-ratio tokamak (major radius 0.3 m, minor radius 0.2 m, toroidal field of up to 0.5 T), capable of inductive ohmic (OH) current drive, Coaxial Helicity Injection (CHI) current drive, or combinations of both. The temperature and density characteristics have been characterized by a ruby laser MPTS diagnostic at up to six locations within the plasma for a single diagnostic time per discharge. Observed hollow temperature profiles of CHI discharges are inconsistent with open flux only predictions for CHI and indicate a closed flux region during CHI current drive.

• OSTI ID: 21120515
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 15; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASPECT RATIO
CURRENTS
DENSITY
ELECTRIC DISCHARGES
ELECTRON TEMPERATURE
HELICITY
ION TEMPERATURE
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA DIAGNOSTICS
RUBY LASERS
SPHERICAL CONFIGURATION
THOMSON SCATTERING
TOKAMAK DEVICES