Effect of partially-screened nuclei on fast-electron dynamics

Abstract

We analyze the dynamics of fast electrons in plasmas containing partially ionized impurity atoms, where the screening effect of bound electrons must be included. We derive analytical expressions for the deflection and slowing-down frequencies, and show that they are increased significantly compared to the results obtained with complete screening, already at sub-relativistic electron energies. Furthermore, we show that the modifications to the deflection and slowing down frequencies are of equal importance in describing the runaway current evolution. Our results greatly affect fast-electron dynamics and have important implications, e.g. for the efficacy of mitigation strategies for runaway electrons in tokamak devices, and energy loss during relativistic breakdown in atmospheric discharges.

arXiv comment6 pages, 3 figures, fixed minor typos

References in corpus (4)

• Effective Critical Electric Field for Runaway-Electron Generation
• Numerical calculation of the runaway electron distribution function and associated synchrotron emission
• Kinetic modelling of runaway electrons in dynamic scenarios
• Effect of bremsstrahlung radiation emission on fast electrons in plasmas

Cited by in corpus (16)

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• Generalized collision operator for fast electrons interacting with partially ionized impurities
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• Spatiotemporal analysis of the runaway distribution function from synchrotron images in an ASDEX Upgrade disruption
• Structure and overstability of resistive modes with runaway electrons
• Impact of a minority relativistic electron tail interacting with a thermal plasma containing high-atomic-number impurities
• Spatially-dependent modeling and simulation of runaway electron mitigation in DIII-D
• The constraint of plasma power balance on runaway avoidance
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• Experimental and synthetic measurements of polarized synchrotron emission from runaway electrons in Alcator C-Mod
• A fluid-kinetic framework for self-consistent runaway-electron simulations
• Runaway electron modelling in the self-consistent core European Transport Simulator, ETS
• Drift surface solver for runaway electron current dominant equilibria during the Current Quench