Kinetic effects on plasma flow in the magnetic mirror

This work describes the results of quasi-two-dimensional kinetic modeling of plasmas in the magnetic mirror using Particle-in-Cell methods. The drift-kinetic equations of motion for electrons and ions were implemented into the EDIPIC code [1]. The effects of the inhomogeneous magnetic field are included by varying the cell's volume and using the modified Poisson equation corresponding to the flux tube approximation. The electron collisions are included using the Langevin approach. Results of full kinetic simulations are compared with fluid analytical theory and quasineutral simulations. The role of the boundary sheath on the total potential drop is investigated at different expansion ratios in full mirror and expander only configurations. The simulations were performed in full self-consistent (full electron and ion dynamics) and reduced models with fixed potential and/or fixed ion density. The effects of electron collisions on the electron flux into the loss cone were studied and compared with earlier analytical and computational results [2-4]. The role of electrons trapped in the expander region and the effects of inherent PIC numerical noise are investigated in different regimes.



References

[1] D. Sydorenko, Ph.D. Thesis, University of Saskatchewan (2006); D. Sydorenko, A. Smolyakov, I. Kaganovich, and Y. Raitses, Physics of Plasmas 13, 014501 (2006); https://github.com/PrincetonUniversity/EDIPIC.

[2] V.P. Pastukhov, Nuclear Fusion 14 , 3-6 (1974).

[3] V. N. Khudik, Nuclear Fusion 37, 189-198 (1997).

[4] R. H. Cohen, M. E. Rensink, T. A. Cutler, and A. A. Mirin, Nuclear Fusion 18, 1229-1243 (1978).