Polarimetry of motional Stark effect and determination of current profiles in DIII-D (invited)

摘要: The motional electric field E=v×B, where v is the velocity and B tokamak magnetic field, produces a strong Stark effect in spectral lines emitted by hydrogenic neutral beams. tilt angle of line, quantity related directly to distribution plasma toroidal current, deduced from measurement direction polarization components. In DIII‐D tokamak, Balmer‐α line deuterium one high‐power heating beams analyzed. A multichord polarimeter measures pitch at eight spatial locations covering ∼0.6 nominal diameter midplane outboard side. diagnostic offers 2–8‐cm resolution major radius 1‐ms integration time. accuracy necessary for an adequate reconstruction current profiles obtained with use active polarizing elements which produce high‐frequency intensity modulation amplitude ...