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Gyrocenter-gauge kinetic algorithm for high frequency waves in magnetized plasmas

Zhi Yu and Hong Qin

Phys. Plasmas 16, 032507 (2009)

A kinetic simulation algorithm for high-frequency electromagnetic waves has been developed based on the gyrocenter-gauge kinetic theory. The magnetized plasma system is simulated in the gyrocenter coordinate system. The gyrocenter distribution function F is sampled on the gyrocenter, parallel velocity, and magnetic moment coordinates. The gyrocenter-gauge function S is sampled on the Kruskal rings and shares the first five coordinates with F. The moment integral of pullback transformation is directly calculated using the Monte Carlo method and an explicit difference scheme for Maxwell’s equations in terms of potentials is adopted. The new algorithm has been successfully applied to the simulation studies of high frequency extraordinary wave, electron Bernstein wave, and the mode conversion process between the extraordinary wave and the electron Bernstein wave in inhomogeneous plasmas

Gyrokinetic equation in an exact canonical Hamiltonian coordinate system and its orbit-averaged form

Lei Qi and Shaojie Wang

Phys. Plasmas 16, 062504 (2009)

A previous gauge-invariant gyrokinetic equation based on an approximate canonical Hamiltonian coordinate system is extended to an exact canonical Hamiltonian coordinate system with the time scale well separated. By using this formalism a new orbit-averaged gyrokinetic equation, which is valid for both trapped and passing particles, is established.

Electron temperature difference between the o-point and x-point of a magnetic island

Jinhong Yang, Qingquan Yu, Sizheng Zhu, and G. Zhuang

Phys. Plasmas 16, 092308 (2009) | Cited 1 times

The electron temperature difference between the o-point and the x-point of a magnetic island is studied numerically by solving the two-dimensional energy transport equation. It is found that, even without a localized radio-frequency heating at the island’s o-point, there is usually a temperature difference between these two points. This difference depends on the radial profile of the heating power deposition, the ratio between the parallel and the perpendicular heat conductivity and the island width, and it takes a minimum when the island width is about twice the local heat diffusion layer width. The effect of the temperature difference on the island growth is further studied, and the peaked heating power density profile at magnetic axis is found be destabilizing.