Effective Critical Electric Field for Runaway-Electron Generation
Journal article, 2015

In this Letter we investigate factors that influence the effective critical electric field for runaway-electron generation in plasmas. We present numerical solutions of the kinetic equation and discuss the implications for the threshold electric field. We show that the effective electric field necessary for significant runaway-electron formation often is higher than previously calculated due to both (1) extremely strong dependence of primary generation on temperature, and (2) synchrotron radiation losses. We also address the effective critical field in the context of a transition from runaway growth to decay. We find agreement with recent experiments, but show that the observation of an elevated effective critical field can mainly be attributed to changes in the momentum- space distribution of runaways, and only to a lesser extent to a de facto change in the critical field.

Author

Adam Stahl

Chalmers, Applied Physics, Nuclear Engineering

Eero Hirvijoki

Chalmers, Applied Physics, Nuclear Engineering

Joan Decker

Chalmers, Applied Physics, Nuclear Engineering

Ecole Polytechnique Federale De Lausanne

Ola Embréus

Chalmers, Applied Physics, Nuclear Engineering

Tünde Fülöp

Chalmers, Applied Physics, Nuclear Engineering

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 114 11 115002- 115002

Areas of Advance

Energy

Roots

Basic sciences

Subject Categories

Fusion, Plasma and Space Physics

DOI

10.1103/PhysRevLett.114.115002

More information

Latest update

11/23/2018