Nonlinear behaviour of collisionless double tearing mode induced by electron inertia

Matsumoto, Taro; Naito, Hiroshi*; Tokuda, Shinji; Kishimoto, Yasuaki*

Nuclear Fusion, 45(11), p.1264 - 1270, 2005/11

https://doi.org/10.1088/0029-5515/45/11/006

A gyrokinetic particle simulation is executed to clarify the effect of the electron inertia on the MHD phenomena in the reversed shear configuration (RSC) of a cylindrical tokamak plasma. It is found that the collisionless (kinetic) double tearing modes grow up at the Alfvn time scale, and nonlinearly induce the internal collapse when the helical flux at the magnetic axis is less than that at the outer resonant surface. After the internal collapse, the secondary reconnection is induced by the current concentration due to the convective flow. It is also clarified that a nonlinear dynamics accompanied with the elementary processes caused by the flow can generate a new RSC with resonant surfaces. In the presence of the density gradient, after the full reconnection induced by the mode, the radial electric field is found to be generated due to the difference of the motion between ions and electrons. However, the intensity of the radial field is not so large as that induced by the collisionless kink mode.

Generation of radial electric field induced by collisionless internal kink mode with density gradient

Matsumoto, Taro; Tokuda, Shinji; Kishimoto, Yasuaki; Naito, Hiroshi*

Physics of Plasmas, 10(1), p.195 - 203, 2003/01

https://doi.org/10.1063/1.1528608

Effects of density gradient on the collisionless m=1 internal kink mode in a cylindrical tokamak plasma are studied by the gyro-kinetic particle simulations. When the density gradient is not large enough to change the full reconnection process, the phenomena after the full reconnection, such as the secondary reconnection and the evolution of the safety factor profile, are changed considerably due to the self-generated radial electric field, i.e. the m=0 mode. The growing mechanism is explained by the difference of drift motion between ions and electrons, which is caused by the fast parallel motion of electron. Once the radial electric field is triggered by the symmetrical flow induced by the m=1 mode, the m=0 mode grows up to the same level as the m=1 mode, and drives an plasma rotation in the ion diamagnetic direction, which breaks the symmetrical plasma flow induced by the m=1 mode. The density and current distributions, and minimum safety factor after the full reconnection, are found to be affected by the asymmetrical flow driven by the m=1 and m=0 modes.

ETC-Rel code; Orbit trace code of relativistic electrons in a tokamak

Tokuda, Shinji; *

JAERI-Data/Code 98-032, 36 Pages, 1998/11

JAERI-Data-Code-98-032.pdf:1.93MB

no abstracts in English

Observation of collisionless drift waves in a toroidal hexapole

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Physical Review Letters, 31(2), p.82 - 86, 1973/02

https://doi.org/10.1103/PhysRevLett.31.82

no abstracts in English