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Application of the Ito theory for Monte Carlo simulation of plasma diffusion

Published online by Cambridge University Press:  25 June 2018

Anatolii Gurin*
Affiliation:
Institute for Nuclear Research of National Academy of Science, Kiev 03028, Ukraine
Victor Goloborod’ko
Affiliation:
Institute for Nuclear Research of National Academy of Science, Kiev 03028, Ukraine
*
Email address for correspondence: aagurin@ukr.net

Abstract

In this paper the full set of stochastic differential equations (SDEs) are presented describing the guiding centre motion of test charged particles in a plasma with an arbitrary inhomogeneous magnetic field, when the drift approximation is applicable. The derivation is based on the Ito formula which is used to determine stochastic differentials of functions of the non-gyro-averaged velocity diffusion in strict correspondence with the general kinetic equations involving Coulomb collision operators. The drift SDEs are obtained by calculating the Ito stochastic integrals within time intervals admitting the gyro-averaging procedure. The proposed SDEs reproduce the well-known Monte Carlo operators for orbital invariants, however additionally accounting for the spatial drift caused by the cross-field diffusion process with a classical diffusion coefficient. All SDE coefficients are explicitly expressed in terms of the Rosenbluth potentials in a gyro-tropic or isotropic background plasma. The SDEs are presented in particular for the case of an axisymmetric toroidal magnetic configuration to describe the spatial two-dimensional poloidal diffusion process providing a detailed description of neoclassical orbital effects.

Type
Research Article
Copyright
© Cambridge University Press 2018 

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References

Bogoliubov, N. N. & Mitropolski, Y. A. 1961 Asymptotic Methods in the Theory of Non-Linear Oscilations. Gordon and Breach.Google Scholar
Boozer, A. 2002 Monte Carlo collision operators for use with exact trajectory integrators. Phys. Plasmas 2, 4389.Google Scholar
Brizard, A. 2004 A guiding-center Fokker–Planck collision operator for nonuniform magnetic fields. Phys. Plasmas 11, 4429.CrossRefGoogle Scholar
Chang, L., Hong, Q. & Chenhao, M. X. 2011 A gyrokinetic collision operator for magnetized plasmas. Phys. Plasmas 18, 032502.Google Scholar
Eriksson, L.-G. & Helander, P. 1994 Monte Carlo operators for orbit-averaged Fokker–Planck equations. Phys. Plasmas 1 (2), 308.Google Scholar
Galeev, A. & Sagdeev, R. 1979 Neoclassical theory of diffusion. In Reviews of Plasma Physics (ed. Leontovich, M.), vol. 7, p. 257. Consultants Bureau.Google Scholar
Gikhman, I. & Skorohod, A. 1972 Stochastic Differential Equations. Springer.Google Scholar
Gurin, A. & Yavorskij, V. 2017 Stochastic differential equations, stochastic integrals and equations of charged particles motion in toroidal plasmas. Probl. At. Sci. Technol. 1, 8083.Google Scholar
Hinton, F. & Hazeltine, R. 1976 Theory of plasma transport in toroidal confinement systems. Rev. Mod. Phys. 48 (2), 1239.CrossRefGoogle Scholar
Hirvijoki, E., Brizard, A., Snicker, A. & Kurki-Suoni, T. 2013 Monte Carlo implementation of a guiding-center Fokker–Planck kinetic equation. Phys. Plasmas 20, 092505.CrossRefGoogle Scholar
Ito, K. 1944 Stochastic integral. Proc. Imp. Acad., Tokyo 20 (8), 519524.Google Scholar
Kloeden, P. & Platen, E. 1995 Numerical Solution of Stochastic Differential Equations. Springer.Google Scholar
Longmire, C. & Rosenbluth, M. 1956 Diffusion of charged particles across a magnetic field. Phys. Rev. 103 (3), 507510.Google Scholar
Rosenbluth, M., MacDonald, W. & Judd, D. 1957 Fokker–Planck equation for an inverse-square force. Phys. Rev. 1, 107.Google Scholar
Tessarotto, M., White, R. & Zheng, L. 1994 Monte Carlo approach to collisional transport. Phys. Plasmas 1, 26032613.CrossRefGoogle Scholar
Xu, X. & Rosenbluth, M. 1991 Numerical simulation of ion temperature gradient driven modes. Phys. Fluids B 3, 627643.CrossRefGoogle Scholar