Related Experiment Videos
Modification of the current profile in high-performance plasmas using off-axis electron-cyclotron-current drive in
M Murakami1, M R Wade, C M Greenfield
1Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. murakami@fusion.gat.com
Physical Review Letters
|July 15, 2003
Summary
Advanced Tokamak experiments successfully modified plasma current profiles using off-axis electron cyclotron current drive (ECCD). This achieved high beta and improved confinement, with over 85% of current driven non-inductively.
Area of Science:
- Plasma physics
- Fusion energy research
- Magnetic confinement fusion
Background:
- Advanced Tokamak operational modes require specific plasma profiles.
- Controlling plasma current profiles is crucial for stable fusion reactions.
- Non-inductive current drive methods are essential for steady-state fusion.
Purpose of the Study:
- To investigate the effectiveness of off-axis electron cyclotron current drive (ECCD) in modifying plasma current profiles.
- To assess the impact of ECCD on achieving Advanced Tokamak parameters.
- To explore the relationship between magnetic shear and plasma confinement.
Main Methods:
- Experiments conducted on the DIII-D tokamak.
- Utilized off-axis electron cyclotron current drive (ECCD) for plasma control.
- Analyzed plasma profiles, including toroidal beta and magnetic shear.
Main Results:
- Demonstrated successful modification of the plasma current profile using ECCD.
- Achieved high toroidal beta (near 3%) and high bootstrap current fraction.
- Observed strong negative central magnetic shear, leading to confinement improvements.
Conclusions:
- Off-axis ECCD is a viable method for controlling plasma profiles in high-beta regimes.
- ECCD facilitates the simultaneous achievement of high beta, high bootstrap current, and improved confinement.
- Negative central magnetic shear induced by ECCD enhances core plasma confinement.