Electron cyclotron current drive and current profile control in the DIII-D tokamak
- General Atomics, San Diego, CA (United States); and others
Recent work in many tokamaks has indicated that optimization of the current profile is a key element needed to sustain modes of improved confinement and stability. Generation of localized current through application of electron cyclotron (EC) waves offers a means of accomplishing this. In addition to profile control, electron cyclotron current drive (ECCD) is useful for sustaining the bulk current in a steady state manner and for instability suppression. ECCD is particularly well suited for control of the current profile because the location of the driven current can be regulated by external means, through steering of the incident EC waves and setting the magnitude of the toroidal magnetic field. Under most conditions the location of the driven current is insensitive to the plasma parameters. Central ECCD has been studied in a number of tokamaks and found to have characteristics commensurate with theory as expressed through ray tracing and Fokker-Planck computer codes. The present experiments on DIII-D explore central current drive and are the first to test off-axis ECCD. These experiments are unique in using internal measurements of the magnetic field to determine the magnitude and profile of driven current.
- Research Organization:
- General Atomics, San Diego, CA (United States); Princeton Univ., Princeton Plasma Physics Lab., NJ (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Texas, Austin, TX (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC03-89ER51114; AC02-76CH03073; AC05-96OR22464; FG03-97ER54415
- OSTI ID:
- 639765
- Report Number(s):
- GA-A22916; CONF-980678-; ON: DE98007300; TRN: 98:007886
- Resource Relation:
- Conference: 25. European Physical Society conference on controlled fusion and plasma physics, Prague (Czech Republic), 29 Jun - 3 Jul 1998; Other Information: PBD: Jul 1998
- Country of Publication:
- United States
- Language:
- English
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