Time: Tuesday, April 18th , 3:00 pm
Venue: Rm. 413, Bld. 11#, Yuquan Campus
Title about: Modelling the Lagrangian of magnetized plasmas with electrostatic perturbations and low- frequency magnetic perturbations by gyrokinetic model
Speaker: 张双喜 博士
It’s well-known that due to the fact that the inverse-square structure of Coulomb force determines Poisson’s equation which associates the electrostatic potential with the charge density on particle’s coordinates, the fundamental Lagrangian 1-form, which determines the dynamics of all ions and electrons in the magnetized plasma with electrostatic perturbations, can be modeled by a Vlasov-Poisson model. By transforming this Lagrangian 1-form to the new one on gyrocenter coordinates up to the second order, the new potential includes the potential generated by Coulomb force on the new coordinates plus a finite Larmor radius term. It’s shown that the fundamental Lagrangian 1-form on the new coordinates can still be modeled by a gyrokinetic Vlasov-Poisson model with the polarization density recovered on the new coordinates. The numerical application of this new model could help reduce numerical error, numerical instabilities and numerical burden for the simulation of the electrostatic turbulence in magnetized plasma.
The similar method can also be applied to low-frequency magnetic perturbations resulting a gyrokinetic Ampere-Poisson model. Eventually, a gyrokinetic Ampere-Poisson-Vlasov model can be derived by combining electrostatic perturbations and low-frequency magnetic perturbations together.