### 摘要

Discharges with negative central magnetic shear (NCS) hold the promise of enhanced fusion performance in advanced tokamaks. However, stability to long wavelength magnetohydrodynamic modes is needed to take advantage of the improved confinement found in NCS discharges. The stability limits seen in DIII-D [J. L. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)] experiments depend on the pressure and current density profiles and are in good agreement with stability calculations. Discharges with a strongly peaked pressure profile reach a disruptive limit at low beta, [formula omitted] (% m T/MA), caused by an [formula omitted] ideal internal kink mode or a global resistive instability close to the ideal stability limit. Discharges with a broad pressure profile reach a soft beta limit at significantly higher beta, [formula omitted] to 5, usually caused by instabilities with [formula omitted] and usually driven near the edge of the plasma. With broad pressure profiles, the experimental stability limit is independent of the magnitude of negative shear but improves with the internal inductance, corresponding to lower current density near the edge of the plasma. Understanding of the stability limits in NCS discharges has led to record DIII-D fusion performance in discharges with a broad pressure profile and low edge current density.

原文 | English |
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頁（從 - 到） | 1783-1791 |

頁數 | 9 |

期刊 | Physics of Plasmas |

卷 | 4 |

發行號 | 5 |

DOIs | |

出版狀態 | Published - 1997 五月 |

### All Science Journal Classification (ASJC) codes

- Condensed Matter Physics

## 指紋 深入研究「Stability of negative central magnetic shear discharges in the DIII-D tokamak」主題。共同形成了獨特的指紋。

## 引用此

*Physics of Plasmas*,

*4*(5), 1783-1791. https://doi.org/10.1063/1.872366