An advection-diffusion model for cross-field runaway electron transport in perturbed magnetic fields

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Princeton University
  • Swiss Federal Institute of Technology Lausanne
  • Chalmers University of Technology

Abstract

Disruption-generated runaway electrons (RE) present an outstanding issue for ITER. The predictive computational studies of RE generation rely on orbit-averaged computations and, as such, they lack the effects from the magnetic field stochasticity. Since stochasticity is naturally present in post-disruption plasma, and externally induced stochastization offers a prominent mechanism to mitigate RE avalanche, we present an advection-diffusion model that can be used to couple an orbit-following code to an orbit-averaged tool in order to capture the cross-field transport and to overcome the latter's limitation. The transport coefficients are evaluated via a Monte Carlo method. We show that the diffusion coefficient differs significantly from the well-known Rechester-Rosenbluth result. We also demonstrate the importance of including the advection: it has a two-fold role both in modelling transport barriers created by magnetic islands and in amplifying losses in regions where the islands are not present.

Details

Original languageEnglish
Article number125017
Pages (from-to)1-11
JournalPlasma Physics and Controlled Fusion
Volume58
Issue number12
Publication statusPublished - 17 Nov 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • advection, diffusion, radial transport, runaway electron, stochastic magnetic field

ID: 14982140