Gyrokinetic simulation of the tearing mode instability

A recently developed split-weight perturbative particle simulation scheme for finite-$\beta$ plasmas in the presence of background inhomogeneities which analytically separates the additional adiabatic response of the particles associated with the quasi-static bending of the magnetic field lines [1] has been generalized to the sheared magnetic field geometry. The new scheme has been implemented in a 2D particle-in-cell code in slab geometry with drift-kinetic electrons and gyrokinetic ions. The electrons pitch-scattering collision operator has also been implemented to study collisionless as well as collisional tearing, and drift-tearing instabilities. In this paper the results of linear simulations of tearing and drift-tearing modes for realistic mass ratio $m_i/m_e=1837$ and different values of plasma $\beta$, electron-ion collision frequency, density and temperature gradients are presented and compared to the solution of the eigenvalue equation [2]. We will also present preliminary results of collisionless tearing mode simulations in cylindrical geometry using tokamak turbulence code GTS.\\[4pt] [1] E. A. Startsev and W. W. Lee, Phys. Plasmas 21, 022505 (2014).\\[0pt] [2] J. F. Drake and Y. C. Lee, Phys. Fluids 20, 1341 (1977).