Runaway electrons and ITER

Boozer, Allen H.

doi:10.1088/1741-4326/aa6355

Runaway electrons and ITER

Journal Article · Fri Mar 24 00:00:00 EDT 2017 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/aa6355· OSTI ID:1429495

Boozer, Allen H. ^[1]

Columbia Univ., New York, NY (United States); Columbia University

The potential for damage, the magnitude of the extrapolation, and the importance of the atypical—incidents that occur once in a thousand shots—make theory and simulation essential for ensuring that relativistic runaway electrons will not prevent ITER from achieving its mission. Most of the theoretical literature on electron runaway assumes magnetic surfaces exist. ITER planning for the avoidance of halo and runaway currents is focused on massive gas or shattered-pellet injection of impurities. In simulations of experiments, such injections lead to a rapid large-scale magnetic-surface breakup. Surface breakup, which is a magnetic reconnection, can occur on a quasi-ideal Alfvénic time scale when the resistance is sufficiently small. Nevertheless, the removal of the bulk of the poloidal flux, as in halo-current mitigation, is on a resistive time scale. The acceleration of electrons to relativistic energies requires the confinement of some tubes of magnetic flux within the plasma and a resistive time scale. The interpretation of experiments on existing tokamaks and their extrapolation to ITER should carefully distinguish confined versus unconfined magnetic field lines and quasi-ideal versus resistive evolution. The separation of quasi-ideal from resistive evolution is extremely challenging numerically, but is greatly simplified by constraints of Maxwell’s equations, and in particular those associated with magnetic helicity. Thus, the physics of electron runaway along confined magnetic field lines is clarified by relations among the poloidal flux change required for an e-fold in the number of electrons, the energy distribution of the relativistic electrons, and the number of relativistic electron strikes that can be expected in a single disruption event.

View Accepted Manuscript (DOE)

Research Organization:: Columbia Univ., New York, NY (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)

Grant/Contract Number:: FG02-03ER54696; SC0016347

OSTI ID:: 1429495

Alternate ID(s):: OSTI ID: 22925681

Journal Information:: Nuclear Fusion, Journal Name: Nuclear Fusion Journal Issue: 5 Vol. 57; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (39)

Collisional avalanche exponentiation of runaway electrons in electrified plasmas Jayakumar, R.; Fleischmann, H. H.; Zweben, S. J. Physics Letters A, Vol. 172, Issue 6 https://doi.org/10.1016/0375-9601(93)90237-T	journal	January 1993
Disruptions in ITER and strategies for their control and mitigation Lehnen, M.; Aleynikova, K.; Aleynikov, P. B. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.10.075	journal	August 2015
Ohm's law for mean magnetic fields Boozer, A. H. Journal of Plasma Physics, Vol. 35, Issue 1 https://doi.org/10.1017/S0022377800011181	journal	February 1986
Energetic electron transport in the presence of magnetic perturbations in magnetically confined plasmas Papp, G.; Drevlak, M.; Pokol, G. I. Journal of Plasma Physics, Vol. 81, Issue 5 https://doi.org/10.1017/S0022377815000537	journal	July 2015
Resistive stability of a plasma with runaway electrons Helander, P.; Grasso, D.; Hastie, R. J. Physics of Plasmas, Vol. 14, Issue 12 https://doi.org/10.1063/1.2817016	journal	December 2007
Some properties of the M3D-C1 form of the three-dimensional magnetohydrodynamics equations Breslau, J.; Ferraro, N.; Jardin, S. Physics of Plasmas, Vol. 16, Issue 9 https://doi.org/10.1063/1.3224035	journal	September 2009
Passive runaway electron suppression in tokamak disruptions Smith, H. M.; Boozer, A. H.; Helander, P. Physics of Plasmas, Vol. 20, Issue 7 https://doi.org/10.1063/1.4813255	journal	July 2013
Growth and decay of runaway electrons above the critical electric field under quiescent conditions Paz-Soldan, C.; Eidietis, N. W.; Granetz, R. Physics of Plasmas, Vol. 21, Issue 2 https://doi.org/10.1063/1.4866912	journal	February 2014
An ITPA joint experiment to study runaway electron generation and suppression Granetz, R. S.; Esposito, B.; Kim, J. H. Physics of Plasmas, Vol. 21, Issue 7 https://doi.org/10.1063/1.4886802	journal	July 2014
Formation of current sheets in magnetic reconnection Boozer, Allen H. Physics of Plasmas, Vol. 21, Issue 7 https://doi.org/10.1063/1.4890491	journal	July 2014
Theory of runaway electrons in ITER: Equations, important parameters, and implications for mitigation Boozer, Allen H. Physics of Plasmas, Vol. 22, Issue 3 https://doi.org/10.1063/1.4913582	journal	March 2015
Three-dimensional non-linear magnetohydrodynamic modeling of massive gas injection triggered disruptions in JET Fil, A.; Nardon, E.; Hoelzl, M. Physics of Plasmas, Vol. 22, Issue 6 https://doi.org/10.1063/1.4922846	journal	June 2015
Characteristic time for halo current growth and rotation Boozer, Allen H. Physics of Plasmas, Vol. 22, Issue 10 https://doi.org/10.1063/1.4933363	journal	October 2015
Adjoint Fokker-Planck equation and runaway electron dynamics Liu, Chang; Brennan, Dylan P.; Bhattacharjee, Amitava Physics of Plasmas, Vol. 23, Issue 1 https://doi.org/10.1063/1.4938510	journal	January 2016
Thermal quench mitigation and current quench control by injection of mixed species shattered pellets in DIII-D Shiraki, D.; Commaux, N.; Baylor, L. R. Physics of Plasmas, Vol. 23, Issue 6 https://doi.org/10.1063/1.4954389	journal	June 2016
Runaway electrons and magnetic island confinement Boozer, Allen H. Physics of Plasmas, Vol. 23, Issue 8 https://doi.org/10.1063/1.4960969	journal	August 2016
Loss of relativistic electrons when magnetic surfaces are broken Boozer, Allen H.; Punjabi, Alkesh Physics of Plasmas, Vol. 23, Issue 10 https://doi.org/10.1063/1.4966046	journal	October 2016
Efficiency of current drive by fast waves Karney, Charles F. F.; Fisch, Nathaniel J. Physics of Fluids, Vol. 28, Issue 1 https://doi.org/10.1063/1.865191	journal	January 1985
Plasma simulation studies using multilevel physics models Park, W.; Belova, E. V.; Fu, G. Y. Physics of Plasmas, Vol. 6, Issue 5 https://doi.org/10.1063/1.873437	journal	May 1999
A Theorem on Force-Free Magnetic Fields Woltjer, L. Proceedings of the National Academy of Sciences, Vol. 44, Issue 6 https://doi.org/10.1073/pnas.44.6.489	journal	June 1958
Energy dissipation of Alfven wave packets deformed by irregular magnetic fields in solar-coronal arches Similon, Philippe L.; Sudan, R. N. The Astrophysical Journal, Vol. 336 https://doi.org/10.1086/167023	journal	January 1989
Relativistic limitations on runaway electrons Connor, J. W.; Hastie, R. J. Nuclear Fusion, Vol. 15, Issue 3 https://doi.org/10.1088/0029-5515/15/3/007	journal	June 1975
Theory for avalanche of runaway electrons in tokamaks Rosenbluth, M. N.; Putvinski, S. V. Nuclear Fusion, Vol. 37, Issue 10 https://doi.org/10.1088/0029-5515/37/10/I03	journal	October 1997
Chapter 3: MHD stability, operational limits and disruptions Hender, T. C.; Wesley, J. C.; Bialek, J. Nuclear Fusion, Vol. 47, Issue 6 https://doi.org/10.1088/0029-5515/47/6/S03	journal	June 2007
Control and dissipation of runaway electron beams created during rapid shutdown experiments in DIII-D Hollmann, E. M.; Austin, M. E.; Boedo, J. A. Nuclear Fusion, Vol. 53, Issue 8 https://doi.org/10.1088/0029-5515/53/8/083004	journal	July 2013
Radiation asymmetries during the thermal quench of massive gas injection disruptions in JET Lehnen, M.; Gerasimov, S. N.; Jachmich, S. Nuclear Fusion, Vol. 55, Issue 12 https://doi.org/10.1088/0029-5515/55/12/123027	journal	November 2015
Non-axisymmetric magnetic fields and toroidal plasma confinement Boozer, Allen H. Nuclear Fusion, Vol. 55, Issue 2 https://doi.org/10.1088/0029-5515/55/2/025001	journal	January 2015
Plasma vertical stabilisation in ITER Gribov, Y.; Kavin, A.; Lukash, V. Nuclear Fusion, Vol. 55, Issue 7 https://doi.org/10.1088/0029-5515/55/7/073021	journal	June 2015
Scaling of the MHD perturbation amplitude required to trigger a disruption and predictions for ITER de Vries, P. C.; Pautasso, G.; Nardon, E. Nuclear Fusion, Vol. 56, Issue 2 https://doi.org/10.1088/0029-5515/56/2/026007	journal	December 2015
Halo current, runaway electrons and disruption mitigation in ITER Putvinski, S.; Barabaschi, P.; Fujisawa, N. Plasma Physics and Controlled Fusion, Vol. 39, Issue 12B https://doi.org/10.1088/0741-3335/39/12B/013	journal	December 1997
The NIMROD code: a new approach to numerical plasma physics Glasser, A. H.; Sovinec, C. R.; Nebel, R. A. Plasma Physics and Controlled Fusion, Vol. 41, Issue 3A https://doi.org/10.1088/0741-3335/41/3A/067	journal	January 1999
External kink (peeling) modes in x-point geometry Huysmans, G. T. A. Plasma Physics and Controlled Fusion, Vol. 47, Issue 12 https://doi.org/10.1088/0741-3335/47/12/003	journal	October 2005
Two beneficial non-axisymmetric perturbations to tokamaks Boozer, Allen H. Plasma Physics and Controlled Fusion, Vol. 53, Issue 8 https://doi.org/10.1088/0741-3335/53/8/084002	journal	May 2011
Magnetic reconnection: from the Sweet–Parker model to stochastic plasmoid chains Loureiro, N. F.; Uzdensky, D. A. Plasma Physics and Controlled Fusion, Vol. 58, Issue 1 https://doi.org/10.1088/0741-3335/58/1/014021	journal	November 2015
Progress in understanding disruptions triggered by massive gas injection via 3D non-linear MHD modelling with JOREK Nardon, E.; Fil, A.; Hoelzl, M. Plasma Physics and Controlled Fusion, Vol. 59, Issue 1 https://doi.org/10.1088/0741-3335/59/1/014006	journal	October 2016
Adjoint method and runaway electron avalanche Liu, Chang; Brennan, Dylan P.; Boozer, Allen H. Plasma Physics and Controlled Fusion, Vol. 59, Issue 2 https://doi.org/10.1088/1361-6587/59/2/024003	journal	December 2016
Generation of runaway electrons during the thermal quench in tokamaks Aleynikov, Pavel; Breizman, Boris N. Nuclear Fusion, Vol. 57, Issue 4 https://doi.org/10.1088/1741-4326/aa5895	journal	February 2017
Effective Critical Electric Field for Runaway-Electron Generation Stahl, A.; Hirvijoki, E.; Decker, J. Physical Review Letters, Vol. 114, Issue 11 https://doi.org/10.1103/PhysRevLett.114.115002	journal	March 2015
Relaxation of Toroidal Plasma and Generation of Reverse Magnetic Fields Taylor, J. B. Physical Review Letters, Vol. 33, Issue 19 https://doi.org/10.1103/PhysRevLett.33.1139	journal	November 1974

Cited By (18)

A backward Monte-Carlo method for time-dependent runaway electron simulations Zhang, Guannan; del-Castillo-Negrete, Diego Physics of Plasmas, Vol. 24, Issue 9 https://doi.org/10.1063/1.4986019	journal	September 2017
Resolving runaway electron distributions in space, time, and energy Paz-Soldan, C.; Cooper, C. M.; Aleynikov, P. Physics of Plasmas, Vol. 25, Issue 5 https://doi.org/10.1063/1.5024223	journal	May 2018
Role of Kinetic Instability in Runaway-Electron Avalanches and Elevated Critical Electric Fields Liu, Chang; Hirvijoki, Eero; Fu, Guo-Yong Physical Review Letters, Vol. 120, Issue 26 https://doi.org/10.1103/physrevlett.120.265001	journal	June 2018
Structure and overstability of resistive modes with runaway electrons Liu, Chang; Zhao, Chen; Jardin, Stephen C. arXiv https://doi.org/10.48550/arxiv.2006.08463	text	January 2020
Validity of models for Dreicer generation of runaway electrons in dynamic scenarios Olasz, S.; Embreus, O.; Hoppe, M. arXiv https://doi.org/10.48550/arxiv.2101.02740	text	January 2021
Magnetic reconnection and impulsive instabilities in tokamak plasmas: Some analogies with astrophysical flares Buratti, Paolo Rendiconti Lincei. Scienze Fisiche e Naturali, Vol. 30, Issue S1 https://doi.org/10.1007/s12210-019-00821-9	journal	July 2019
On the breakdown modes and parameter space of ohmic tokamak start-up Peng, Yanli; Jiang, Wei; Innocenti, Maria Elena Journal of Plasma Physics, Vol. 84, Issue 5 https://doi.org/10.1017/s0022377818001046	journal	October 2018
Simulation of stellarator divertors Boozer, Allen H.; Punjabi, Alkesh Physics of Plasmas, Vol. 25, Issue 9 https://doi.org/10.1063/1.5042666	journal	September 2018
Runaway electron experiments at COMPASS in support of the EUROfusion ITER physics research Mlynar, J.; Ficker, O.; Macusova, E. Plasma Physics and Controlled Fusion, Vol. 61, Issue 1 https://doi.org/10.1088/1361-6587/aae04a	journal	November 2018
Magnetic surface loss and electron runaway Boozer, Allen H. Plasma Physics and Controlled Fusion, Vol. 61, Issue 2 https://doi.org/10.1088/1361-6587/aaf293	journal	January 2019
Kink instabilities of the post-disruption runaway electron beam at low safety factor Paz-Soldan, C.; Eidietis, N. W.; Liu, Y. Q. Plasma Physics and Controlled Fusion, Vol. 61, Issue 5 https://doi.org/10.1088/1361-6587/aafd15	journal	March 2019
Test particles dynamics in the JOREK 3D non-linear MHD code and application to electron transport in a disruption simulation Sommariva, C.; Nardon, E.; Beyer, P. Nuclear Fusion, Vol. 58, Issue 1 https://doi.org/10.1088/1741-4326/aa95cd	journal	December 2017
Interpretation of runaway electron synchrotron and bremsstrahlung images Hoppe, M.; Embréus, O.; Paz-Soldan, C. Nuclear Fusion, Vol. 58, Issue 8 https://doi.org/10.1088/1741-4326/aaae15	journal	June 2018
3D two-temperature magnetohydrodynamic modeling of fast thermal quenches due to injected impurities in tokamaks Ferraro, N. M.; Lyons, B. C.; Kim, C. C. Nuclear Fusion, Vol. 59, Issue 1 https://doi.org/10.1088/1741-4326/aae990	journal	November 2018
Physics of runaway electrons in tokamaks Breizman, Boris N.; Aleynikov, Pavel; Hollmann, Eric M. Nuclear Fusion, Vol. 59, Issue 8 https://doi.org/10.1088/1741-4326/ab1822	journal	June 2019
Runaway electron beam stability and decay in COMPASS Ficker, O.; Macusova, E.; Mlynar, J. Nuclear Fusion, Vol. 59, Issue 9 https://doi.org/10.1088/1741-4326/ab210f	journal	August 2019
A linear equation based on signal increments to predict disruptive behaviours and the time to disruption on JET Vega, J.; Murari, A.; Dormido-Canto, S. Nuclear Fusion, Vol. 60, Issue 2 https://doi.org/10.1088/1741-4326/ab5880	journal	December 2019
Interpretation of runaway electron synchrotron and bremsstrahlung images Hoppe, M.; Embréus, O.; Paz-Soldan, C. arXiv https://doi.org/10.48550/arxiv.1712.04193	text	January 2017