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Title: Adjoint Fokker-Planck equation and runaway electron dynamics

Abstract

The adjoint Fokker-Planck equation method is applied to study the runaway probability function and the expected slowing-down time for highly relativistic runaway electrons, including the loss of energy due to synchrotron radiation. In direct correspondence to Monte Carlo simulation methods, the runaway probability function has a smooth transition across the runaway separatrix, which can be attributed to effect of the pitch angle scattering term in the kinetic equation. However, for the same numerical accuracy, the adjoint method is more efficient than the Monte Carlo method. The expected slowing-down time gives a novel method to estimate the runaway current decay time in experiments. A new result from this work is that the decay rate of high energy electrons is very slow when E is close to the critical electric field. This effect contributes further to a hysteresis previously found in the runaway electron population.

Authors:
 [1];  [1];  [1];  [2]
  1. Princeton Univ., NJ (United States)
  2. Columbia Univ., New York, NY (United States)
Publication Date:
Research Org.:
Columbia Univ., NY (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1468793
Alternate Identifier(s):
OSTI ID: 1234783
Grant/Contract Number:  
FG02-03ER54696
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 23; Journal Issue: 1; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
97 MATHEMATICS AND COMPUTING; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Liu, Chang, Brennan, Dylan P., Bhattacharjee, Amitava, and Boozer, Allen H. Adjoint Fokker-Planck equation and runaway electron dynamics. United States: N. p., 2016. Web. doi:10.1063/1.4938510.
Liu, Chang, Brennan, Dylan P., Bhattacharjee, Amitava, & Boozer, Allen H. Adjoint Fokker-Planck equation and runaway electron dynamics. United States. https://doi.org/10.1063/1.4938510
Liu, Chang, Brennan, Dylan P., Bhattacharjee, Amitava, and Boozer, Allen H. Wed . "Adjoint Fokker-Planck equation and runaway electron dynamics". United States. https://doi.org/10.1063/1.4938510. https://www.osti.gov/servlets/purl/1468793.
@article{osti_1468793,
title = {Adjoint Fokker-Planck equation and runaway electron dynamics},
author = {Liu, Chang and Brennan, Dylan P. and Bhattacharjee, Amitava and Boozer, Allen H.},
abstractNote = {The adjoint Fokker-Planck equation method is applied to study the runaway probability function and the expected slowing-down time for highly relativistic runaway electrons, including the loss of energy due to synchrotron radiation. In direct correspondence to Monte Carlo simulation methods, the runaway probability function has a smooth transition across the runaway separatrix, which can be attributed to effect of the pitch angle scattering term in the kinetic equation. However, for the same numerical accuracy, the adjoint method is more efficient than the Monte Carlo method. The expected slowing-down time gives a novel method to estimate the runaway current decay time in experiments. A new result from this work is that the decay rate of high energy electrons is very slow when E is close to the critical electric field. This effect contributes further to a hysteresis previously found in the runaway electron population.},
doi = {10.1063/1.4938510},
journal = {Physics of Plasmas},
number = 1,
volume = 23,
place = {United States},
year = {Wed Jan 13 00:00:00 EST 2016},
month = {Wed Jan 13 00:00:00 EST 2016}
}

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Works referenced in this record:

Radiation reaction induced non-monotonic features in runaway electron distributions
journal, July 2015


Transport in driven plasmas
journal, January 1986


Damping of relativistic electron beams by synchrotron radiation
journal, December 2001

  • Andersson, F.; Helander, P.; Eriksson, L. -G.
  • Physics of Plasmas, Vol. 8, Issue 12
  • DOI: 10.1063/1.1418242

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

On the First Passage Time Probability Problem
journal, February 1951


Current in wave-driven plasmas
journal, January 1986

  • Karney, Charles F. F.; Fisch, Nathaniel J.
  • Physics of Fluids, Vol. 29, Issue 1
  • DOI: 10.1063/1.865975

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


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


Destabilization of magnetosonic-whistler waves by a relativistic runaway beam
journal, June 2006

  • Fülöp, T.; Pokol, G.; Helander, P.
  • Physics of Plasmas, Vol. 13, Issue 6
  • DOI: 10.1063/1.2208327

Determination of the parametric region in which runaway electron energy losses are dominated by bremsstrahlung radiation in tokamaks
journal, July 2007

  • Fernández-Gómez, I.; Martín-Solís, J. R.; Sánchez, R.
  • Physics of Plasmas, Vol. 14, Issue 7
  • DOI: 10.1063/1.2746219

Growth and decay of runaway electrons above the critical electric field under quiescent conditions
journal, February 2014

  • Paz-Soldan, C.; Eidietis, N. W.; Granetz, R.
  • Physics of Plasmas, Vol. 21, Issue 2
  • DOI: 10.1063/1.4866912

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


Experimental Observation of Increased Threshold Electric Field for Runaway Generation due to Synchrotron Radiation Losses in the FTU Tokamak
journal, October 2010


Relativistic limitations on runaway electrons
journal, June 1975


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


Avalanche runaway growth rate from a momentum-space orbit analysis
journal, June 1999

  • Parks, P. B.; Rosenbluth, M. N.; Putvinski, S. V.
  • Physics of Plasmas, Vol. 6, Issue 6
  • DOI: 10.1063/1.873524

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

Effect of magnetic and electrostatic fluctuations on the runaway electron dynamics in tokamak plasmas
journal, October 1999

  • Martín-Solís, J. R.; Sánchez, R.; Esposito, B.
  • Physics of Plasmas, Vol. 6, Issue 10
  • DOI: 10.1063/1.873656

On the Stochastic Theory of Neutron Transport
journal, March 1965

  • Bell, George I.
  • Nuclear Science and Engineering, Vol. 21, Issue 3
  • DOI: 10.13182/NSE65-1

Electron and Ion Runaway in a Fully Ionized Gas. I
journal, July 1959


On the effect of synchrotron radiation and magnetic fluctuations on the avalanche runaway growth rate
journal, September 2000

  • Martı́n-Solı́s, J. R.; Sánchez, R.; Esposito, B.
  • Physics of Plasmas, Vol. 7, Issue 9
  • DOI: 10.1063/1.1287215

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

Zur Theorie des Durchgangs schneller Elektronen durch Materie
journal, January 1932


Works referencing / citing this record:

Resolving runaway electron distributions in space, time, and energy
journal, May 2018

  • Paz-Soldan, C.; Cooper, C. M.; Aleynikov, P.
  • Physics of Plasmas, Vol. 25, Issue 5
  • DOI: 10.1063/1.5024223

A Langevin approach to multi-scale modeling
journal, April 2018


Phase-space dynamics of runaway electrons in magnetic fields
journal, February 2017

  • Guo, Zehua; McDevitt, Christopher J.; Tang, Xian-Zhu
  • Plasma Physics and Controlled Fusion, Vol. 59, Issue 4
  • DOI: 10.1088/1361-6587/aa5952

Conservative magnetic moment of runaway electrons and collisionless pitch-angle scattering
journal, August 2018


Physics of runaway electrons in tokamaks
journal, June 2019

  • Breizman, Boris N.; Aleynikov, Pavel; Hollmann, Eric M.
  • Nuclear Fusion, Vol. 59, Issue 8
  • DOI: 10.1088/1741-4326/ab1822

Evaluation of Monte Carlo tools for high-energy atmospheric physics II: relativistic runaway electron avalanches
journal, January 2018

  • Sarria, David; Rutjes, Casper; Diniz, Gabriel
  • Geoscientific Model Development, Vol. 11, Issue 11
  • DOI: 10.5194/gmd-11-4515-2018

A Langevin approach to multi-scale modeling
text, January 2018