Self-suppression of double tearing modes via Alfven resonance in rotating tokamak plasmas

Journal Article · Sun May 15 00:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3586258· OSTI ID:21537776

Zhengxiong, Wang; Lai, Wei; Yue, Liu ^[1]; Xiaogang, Wang ^[2]

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1. Key Laboratory of Materials Modification by Beams of the Ministry of Education, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)
2. State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China)

Reversed magnetic shear configuration, a key method for improving plasma confinement in advanced tokamaks, is prone to exciting double tearing modes (DTMs) that can severely degrade the plasma confinement. In this letter, we reveal a new mechanism of suppressing the DTM instability due to the self-induced Alfven resonance in rotating tokamak plasmas. The linear growth rate is reduced from {approx}S{sub Hp}{sup -1/3} of the fast DTM regime to {approx}S{sub Hp}{sup -3/5} of the slow single tearing mode regime, where S{sub Hp} is magnetic Reynolds number. Instead of generating magnetic islands at the inner rational surface that can greatly enhance plasma transport in the core region, the formation of current sheets at resonance layers not only prevents the fast nonlinear DTM reconnection phase but also contributes to plasma heating.

• OSTI ID: 21537776
• Journal Information: Physics of Plasmas, Vol. 18, Issue 5; Other Information: DOI: 10.1063/1.3586258; (c) 2011 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
INSTABILITY GROWTH RATES
MAGNETIC ISLANDS
MAGNETIC REYNOLDS NUMBER
MODE RATIONAL SURFACES
PLASMA CONFINEMENT
PLASMA HEATING
REVERSED SHEAR
ROTATING PLASMA
TEARING INSTABILITY
TOKAMAK DEVICES
CLOSED PLASMA DEVICES
CONFINEMENT
DIMENSIONLESS NUMBERS
HEATING
HYDROMAGNETIC WAVES
INSTABILITY
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC SURFACES
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
REYNOLDS NUMBER
THERMONUCLEAR DEVICES