Reduced Landau collision operator suitable for gyrokinetic particle simulations

Given the importance of the collisionless gyrokinetic formalism [1], the inclusion of self-consistent collisional effects in the neoclassical and collisionless (long-mean-free-path) regimes within the gyrokinetic formalism is of crucial importance in our ability to understand the complex nonlinear dynamics of magnetized fusion plasmas over long time scales. The exact energy-momentum conservation laws of a guiding-center Landau collision operator [2], which play an important role in monitoring the numerical accuracy of gyrokinetic particle simulations, are investigated for arbitrary magnetic-field geometry. \newline [1] A.J. Brizard and T.S. Hahm, Rev. Mod. Phys. 79 (2007) 421. \newline [2] J.W. Burby, A.J. Brizard, and H. Qin, PoP 22 (2015) 100707.