Nonlinear calculation of the m=1 internal kink instability in current carrying stellarators

Technical Report · Wed Feb 01 00:00:00 EST 1978

OSTI ID:6624631

Wakatani, M

Nonlinear properties of the m=1 internal kink mode are shown in a low beta current carrying stellarator. The effects of the external helical magnetic fields are considered through a rotational transform and the magnetic surface is assumed to be circular. Magnetic surfaces inside the iota sub eta + iota sub sigma = 1 surface shift and deform non-circularly, while magnetic surfaces outside the iota sub eta + iota sub sigma = 1 are not disturbed, where iota sub eta is a rotational transform due to helical magnetic fields and iota sub sigma is due to a plasma current. Many higher harmonics are excited after the fundamental mode saturates. When the external helical magnetic fields are lowered, the m=1 tearing mode similar to that in a low beta Tokamak grows and magnetic islands appear near the iota sub eta + iota sub sigma = 1 surface. For adequate helical magnetic fields, the current carrying stellarator becomes stable against both the m=1 internal kink mode and the m=1 internal kink mode and the m=1 tearing mode, without lowering the rotational transform.

• Research Organization: Nagoya Univ. (Japan). Inst. of Plasma Physics
• OSTI ID: 6624631
• Report Number(s): N-78-22908; IPPJ-324
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
KINK INSTABILITY
NONLINEAR PROBLEMS
STELLARATORS
ELECTRIC CURRENTS
MAGNETIC ISLANDS
MAGNETIC SURFACES
TEARING INSTABILITY
CLOSED PLASMA DEVICES
CURRENTS
INSTABILITY
MAGNETIC FIELD CONFIGURATIONS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
700107* - Fusion Energy- Plasma Research- Instabilities