skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Space dependent, full orbit effects on runaway electron dynamics in tokamak plasmas

Abstract

The dynamics of RE (runaway electrons) in fusion plasmas span a wide range of temporal scales, from the fast gyro-motion, ~10–11 s, to the observational time scales, ~10–2 → 1 s. To cope with this scale separation, RE are usually studied within the bounce-average or the guiding center approximations. Although these approximations have yielded valuable insights, a study with predictive capabilities of RE in fusion plasmas calls for the incorporation of full orbit effects in configuration space in the presence of three-dimensional magnetic fields. We present numerical results on this problem using the Kinetic Orbit Runaway electrons Code that follows relativistic electrons in general electric and magnetic fields under the full Lorentz force, collisions, and radiation losses. At relativistic energies, the main energy loss is due to radiation damping, which we incorporate using the Landau-Lifshitz formulation of the Abraham-Lorentz-Dirac force. The main focus is on full orbit effects on synchrotron radiation. It is shown that even in the absence of magnetic field stochasticty, neglecting orbit dynamics can introduce significant errors in the computation of the total radiated power and the synchrotron spectra. The statistics of collisionless (i.e., full orbit induced) pitch angle dispersion, and its key role played on synchrotronmore » radiation, are studied in detail. Numerical results are also presented on the pitch angle dependence of the spatial confinement of RE and on full orbit effects on the competition of electric field acceleration and radiation damping. Lastly, full orbit calculations are used to explore the limitations of gyro-averaging in the relativistic regime. To explore the practical impact of the results, DIII-D and ITER-like parameters are used in the simulations.« less

Authors:
 [1]; ORCiD logo [1];  [1];  [1]; ORCiD logo [1]
  1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8071, USA
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1375656
Alternate Identifier(s):
OSTI ID: 1420618; OSTI ID: 1465072
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Published Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Name: Physics of Plasmas Journal Volume: 24 Journal Issue: 4; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Carbajal, L., del-Castillo-Negrete, D., Spong, D., Seal, S., and Baylor, L. Space dependent, full orbit effects on runaway electron dynamics in tokamak plasmas. United States: N. p., 2017. Web. doi:10.1063/1.4981209.
Carbajal, L., del-Castillo-Negrete, D., Spong, D., Seal, S., & Baylor, L. Space dependent, full orbit effects on runaway electron dynamics in tokamak plasmas. United States. doi:10.1063/1.4981209.
Carbajal, L., del-Castillo-Negrete, D., Spong, D., Seal, S., and Baylor, L. Tue . "Space dependent, full orbit effects on runaway electron dynamics in tokamak plasmas". United States. doi:10.1063/1.4981209.
@article{osti_1375656,
title = {Space dependent, full orbit effects on runaway electron dynamics in tokamak plasmas},
author = {Carbajal, L. and del-Castillo-Negrete, D. and Spong, D. and Seal, S. and Baylor, L.},
abstractNote = {The dynamics of RE (runaway electrons) in fusion plasmas span a wide range of temporal scales, from the fast gyro-motion, ~10–11 s, to the observational time scales, ~10–2 → 1 s. To cope with this scale separation, RE are usually studied within the bounce-average or the guiding center approximations. Although these approximations have yielded valuable insights, a study with predictive capabilities of RE in fusion plasmas calls for the incorporation of full orbit effects in configuration space in the presence of three-dimensional magnetic fields. We present numerical results on this problem using the Kinetic Orbit Runaway electrons Code that follows relativistic electrons in general electric and magnetic fields under the full Lorentz force, collisions, and radiation losses. At relativistic energies, the main energy loss is due to radiation damping, which we incorporate using the Landau-Lifshitz formulation of the Abraham-Lorentz-Dirac force. The main focus is on full orbit effects on synchrotron radiation. It is shown that even in the absence of magnetic field stochasticty, neglecting orbit dynamics can introduce significant errors in the computation of the total radiated power and the synchrotron spectra. The statistics of collisionless (i.e., full orbit induced) pitch angle dispersion, and its key role played on synchrotron radiation, are studied in detail. Numerical results are also presented on the pitch angle dependence of the spatial confinement of RE and on full orbit effects on the competition of electric field acceleration and radiation damping. Lastly, full orbit calculations are used to explore the limitations of gyro-averaging in the relativistic regime. To explore the practical impact of the results, DIII-D and ITER-like parameters are used in the simulations.},
doi = {10.1063/1.4981209},
journal = {Physics of Plasmas},
number = 4,
volume = 24,
place = {United States},
year = {2017},
month = {4}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1063/1.4981209

Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Simulation of runaway electrons during tokamak disruptions
journal, August 2003


Synchrotron radiation from a runaway electron distribution in tokamaks
journal, September 2013

  • Stahl, A.; Landreman, M.; Papp, G.
  • Physics of Plasmas, Vol. 20, Issue 9
  • DOI: 10.1063/1.4821823

Multi-scale full-orbit analysis on phase-space behavior of runaway electrons in tokamak fields with synchrotron radiation
journal, June 2016

  • Wang, Yulei; Qin, Hong; Liu, Jian
  • Physics of Plasmas, Vol. 23, Issue 6
  • DOI: 10.1063/1.4953608

Visible imaging and spectroscopy of disruption runaway electrons in DIII-D
journal, April 2013

  • Yu, J. H.; Hollmann, E. M.; Commaux, N.
  • Physics of Plasmas, Vol. 20, Issue 4
  • DOI: 10.1063/1.4801738

Effective Critical Electric Field for Runaway-Electron Generation
journal, March 2015


Radiation reaction effects on radiation pressure acceleration
journal, December 2010


Runaway electrons in toroidal discharges
journal, June 1979


The critical manifold of the Lorentz-Dirac equation
journal, May 2000


Collisionless pitch-angle scattering of runaway electrons
journal, May 2016


Control and dissipation of runaway electron beams created during rapid shutdown experiments in DIII-D
journal, July 2013


Numerical calculation of the runaway electron distribution function and associated synchrotron emission
journal, March 2014

  • Landreman, Matt; Stahl, Adam; Fülöp, Tünde
  • Computer Physics Communications, Vol. 185, Issue 3
  • DOI: 10.1016/j.cpc.2013.12.004

Simulation of beams or plasmas crossing at relativistic velocity
journal, May 2008


Status of research toward the ITER disruption mitigation system
journal, November 2014

  • Hollmann, E. M.; Aleynikov, P. B.; Fülöp, T.
  • Physics of Plasmas, Vol. 22, Issue 2
  • DOI: 10.1063/1.4901251

Momentum–space structure of relativistic runaway electrons
journal, June 1998

  • Martı́n-Solı́s, J. R.; Alvarez, J. D.; Sánchez, R.
  • Physics of Plasmas, Vol. 5, Issue 6
  • DOI: 10.1063/1.872911

Monte Carlo simulation of runaway electrons in a toroidal geometry
journal, July 1993

  • Heikkinen, J. A.; Sipilä, S. K.; Pättikangas, T. J. H.
  • Computer Physics Communications, Vol. 76, Issue 2
  • DOI: 10.1016/0010-4655(93)90133-W

Runaway electron drift orbits in magnetostatic perturbed fields
journal, March 2011


Hamiltonian formulation of guiding center motion
journal, January 1981

  • Littlejohn, Robert G.
  • Physics of Fluids, Vol. 24, Issue 9
  • DOI: 10.1063/1.863594

Volume-preserving algorithm for secular relativistic dynamics of charged particles
journal, April 2015

  • Zhang, Ruili; Liu, Jian; Qin, Hong
  • Physics of Plasmas, Vol. 22, Issue 4
  • DOI: 10.1063/1.4916570

Theory of runaway electrons in ITER: Equations, important parameters, and implications for mitigation
journal, March 2015


The correct equation of motion of a classical point charge
journal, May 2001


Kinetic modelling of runaway electron avalanches in tokamak plasmas
journal, July 2015


Disruptions in ITER and strategies for their control and mitigation
journal, August 2015


Theory for avalanche of runaway electrons in tokamaks
journal, October 1997


Theory of Two Threshold Fields for Relativistic Runaway Electrons
journal, April 2015


On the Classical Radiation of Accelerated Electrons
journal, June 1949


On the motion of runaway electrons in momentum space
journal, March 1979


Phase-space dynamics of runaway electrons in tokamaks
journal, September 2010

  • Guan, Xiaoyin; Qin, Hong; Fisch, Nathaniel J.
  • Physics of Plasmas, Vol. 17, Issue 9
  • DOI: 10.1063/1.3476268

Effect of ripple on runaway electrons in tokamaks
journal, January 1991


Chapter 3: MHD stability, operational limits and disruptions
journal, June 2007