A plasma with β ≈ 12% has been stably confined in the Levitated Octupole. Although the single-fluid ballooning-instability beta limit is exceeded on the outer flux surfaces, no such mode is observed. Finite-ion-gyroradius effects may account for the observed stability. The single-fluid calculation indicates that the amplitude of the most unstable mode is nearly uniform along the magnetic field line with only slight peaking in the bad-curvature region. The particle confinement time is one quarter of the classical value.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Condensed Matter Physics