Internal disruptions in Heliotron E{sup {asterisk}}

Journal Article · Thu Oct 01 04:00:00 EDT 1998 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.872980· OSTI ID:658489

Carreras, B A; Lynch, V E ^[1]; Zushi, H ^[2]; Ichiguchi, K ^[3]; Wakatani, M ^[4]

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1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
2. Research Institute for Applied Mechanics, Kyushu University, Kasuga 816 (Japan)
3. National Institute for Fusion Science, Toki 509-5292 (Japan)
4. Graduate School of Energy Science, Kyoto University, Kyoto (Japan)

In Heliotron E [K. Uo, Nucl. Fusion {bold 25}, 1243 (1985)] shifted-in vacuum magnetic field configuration, the {ital q} profile varies from just above 2 at the magnetic axis to 0.4 at the plasma edge. For low-{beta} plasmas, resistive interchange modes are the dominant low-{ital n} instabilities at the plasma core. They saturate at low fluctuation levels. Above a threshold value, the ideal m/n=2/1 modes become unstable. They can be resonant or nonresonant modes depending on the value of q(0). In either case, their nonlinear evolution leads to a sudden crash of the pressure within the r/a=0.3 radius (sawtooth oscillation). When beta is increased further, the q=2 surface moves out of the plasma, and the ideal m/n=2/1 modes are effectively stabilized when q(0){lt}1.85. As a result, the sawtooth oscillations are suppressed. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 658489
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 5; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
FLUCTUATIONS
HELIOTRON
MAGNETIC CONFINEMENT
MAGNETIC FIELDS
PLASMA CONFINEMENT
PLASMA DIAGNOSTICS
PLASMA WAVES
SAWTOOTH OSCILLATIONS