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Symplectic integrators with adaptive time step applied to runaway electron dynamics

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Abstract

Studying the dynamics of runaway electrons has theoretical and practical significance. As the system is highly relativistic, multi-scale and nonlinear, accurate and efficient numerical methods with long-term stability are necessary. In this paper, we develop symplectic methods with adaptive time step and discuss the choice of step-size functions in accordance with the simulation problems for runaway electrons. In the implementation, in order to explore the practical impact of runaway electron dynamics, we use the electromagnetic field and some parameters often used in the study of plasma problems. Numerical results show that the new derived symplectic methods with adaptive time step exhibit good invariant-preserving property and superior stability over longtime integration. Moreover, with appropriate adaptive technique, the numerical efficiency in simulations is improved apparently. They are illustrated in the numerical experiments.

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References

  1. Dreicer, H.: Electron and ion runaway in a fully ionized gas. Phys. Rev. 115(2), 238–249 (1959)

    Article  MathSciNet  MATH  Google Scholar 

  2. Kulsrud, R.M., Sun, Y.C., Winsor, N.K., Fallon, H.A.: Runaway electrons in a plasma. Phys. Rev. Lett. 31(11), 690 (1973)

    Article  Google Scholar 

  3. Rosenbluth, M., Putvinski, S.: Theory for avalanche of runaway electrons in tokamaks. Nucl. Fusion 37(10), 1355 (1997)

    Article  Google Scholar 

  4. Bartels, H.W.: Impact of runaway electrons. Fusion Eng. Des. 23(4), 323–328 (1994)

    Article  Google Scholar 

  5. Jaspers, R., Cardozo, N.J.L., Donne, A.J.H., Widdershoven, H.L.M., Finken, K.H.: A synchrotron radiation diagnostic to observe relativistic runaway electrons in a tokamak plasma. Rev. Sci. Instrum. 72(1), 466–470 (2001)

    Article  Google Scholar 

  6. Liu, J., Wang, Y., Qin, H.: Collisionless pitch-angle scattering of runaway electrons. Nucl. Fusion 56(6), 064002 (2016)

    Article  Google Scholar 

  7. Hairer, E., Lubich, C., Wanner, G.: Geometric Numerical Integration: Structure-Preserving Algorithms for Ordinary Differential Equations, vol. 31. Springer Science & Business Media, Berlin (2006)

    MATH  Google Scholar 

  8. Guan, X., Qin, H., Fisch, N.J.: Phase-space dynamics of runaway electrons in tokamaks. Phys. Plasmas 17(9), 092502 (2010)

    Article  Google Scholar 

  9. Zhou, Z., He, Y., Sun, Y., Liu, J., Qin, H.: Explicit symplectic methods for solving charged particle trajectories. Phys. Plasmas 24(5), 052507 (2017)

    Article  Google Scholar 

  10. Zhang, R., Wang, Y., He, Y., Xiao, J., Liu, J., Qin, H., Tang, Y.: Explicit symplectic algorithms based on generating functions for relativistic charged particle dynamics in time-dependent electromagnetic field. Phys. Plasmas 25(2), 022117 (2018)

    Article  Google Scholar 

  11. Zhang, R., Liu, J., Qin, H., Wang, Y., He, Y., Sun, Y.: Volume-preserving algorithm for secular relativistic dynamics of charged particles. Phys. Plasmas 22(4), 044501 (2015)

    Article  Google Scholar 

  12. He, Y., Sun, Y., Zhang, R., Wang, Y., Liu, J., Qin, H.: High order volume-preserving algorithms for relativistic charged particles in general electromagnetic fields. Phys. Plasmas 23(9), 092109 (2016)

    Article  Google Scholar 

  13. Wesson, J., Campbell, D.J.: Tokamaks, vol. 149. Oxford University Press, London (2011)

    Google Scholar 

  14. Wang, Y., Qin, H., Liu, J.: Multi-scale full-orbit analysis on phase-space behavior of runaway electrons in tokamak fields with synchrotron radiation. Phys. Plasmas 23(6), 062505 (2016)

    Article  Google Scholar 

  15. Liu, C., Qin, H., Hirvijoki, E., Wang, Y., Liu, J.: The role of magnetic moment in the collisionless pitch-angle scattering of runaway electrons. arXiv:1804.01971

  16. Wang, Y., Liu, J., Qin, H.: Lorentz covariant canonical symplectic algorithms for dynamics of charged particles. Phys. Plasmas 23(12), 122513 (2016)

    Article  Google Scholar 

  17. Jackson, J.D.: Classical Electrodynamics. Wiley, New York (1999)

    MATH  Google Scholar 

  18. Eriksson, L., Porcelli, F.: Dynamics of energetic ion orbits in magnetically confined plasmas. Plasma Phys. Controlled Fusion 43(4), R145 (2001)

    Article  Google Scholar 

  19. Porcelli, F., Eriksson, L.-G., Furno, I.: Topological transitions of fast ion orbits in magnetically confined plasmas. Phys. Lett. A 216(6), 289–295 (1996)

    Article  Google Scholar 

  20. Carbajal, L., Delcastillonegrete, D., Spong, D., Seal, S., Baylor, L.: Space dependent, full orbit effects on runaway electron dynamics in tokamak plasmas. Phys. Plasmas 24(4), 39–S202 (2017)

    Article  Google Scholar 

  21. Liu, J., Qin, H., Wang, Y., Yang, G., Zheng, J., Yao, Y., Yifeng, Z., Liu, Z., Liu, X.: Largest particle simulations downgrade the runaway electron risk for iter

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Funding

This research was supported by the National Natural Science Foundation of China (11771436, 11261140328, 11305171), by the CAS Program for Interdisciplinary Collaboration Team, the Foundation for Innovative Research Groups of the NNSFC (11321061), and the ITER-China Program (2014GB124005, 2015GB111003), JSPS-NRF-NSFC A3 Foresight Program in the field of Plasma Physics (NSFC-11261140328).

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Correspondence to Yajuan Sun.

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Shi, Y., Sun, Y., He, Y. et al. Symplectic integrators with adaptive time step applied to runaway electron dynamics. Numer Algor 81, 1295–1309 (2019). https://doi.org/10.1007/s11075-018-0636-6

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  • DOI: https://doi.org/10.1007/s11075-018-0636-6

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