M.Barnes W.Dorland T.Tatsuno
Many plasmas of interest to the astrophysical and fusion communities are weakly collisional. In such plasmas, small scales can develop in the distribution of particle velocities, potentially affecting observable quantities such as turbulent fluxes. Consequently, it is necessary to monitor velocity space resolution in gyrokinetic simulations. In thi…
PublishedT. Tatsuno W. Dorland A. A. Schekochihin G. G. Plunk M. Barnes S. C. Cowley G. G. Howes
Electrostatic turbulence in weakly collisional, magnetized plasma can be interpreted as a cascade of entropy in phase space, which is proposed as a universal mechanism for dissipation of energy in magnetized plasma turbulence. When the nonlinear decorrelation time at the scale of the thermal Larmor radius is shorter than the collision time, a broad…
PublishedM. Barnes I. G. Abel W. Dorland D. R. Ernst G. W. Hammett P. Ricci B. N. Rogers A. A. Schekochihin T. Tatsuno
A set of key properties for an ideal dissipation scheme in gyrokinetic simulations is proposed, and implementation of a model collision operator satisfying these properties is described. This operator is based on the exact linearized test-particle collision operator, with approximations to the field-particle terms that preserve conservation laws an…
PublishedI. G. Abel M. Barnes S. C. Cowley W. Dorland G. W. Hammett A. A. Schekochihin T. Tatsuno
We motivate the need to include collisional dissipation in gyrokinetic turbulence simulations, and constract criteria for a physically vaUd model of such dissipation. A new analytically manageable operator satisfying those criteria is presented and transformed into gyrokinetic variables. The form of conservation laws for collision operators in gyro…
Published