An advection-diffusion model for cross-field runaway electron transport in perturbed magnetic fields
Artikel i vetenskaplig tidskrift, 2016

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.

advection

radial transport

stochastic magnetic field

runaway electron

diffusion

Författare

K. Sarkimaki

Aalto-Yliopisto

E. Hirvijoki

Princeton Plasma Physics Laboratory

J. Decker

Ecole Polytechnique Federale De Lausanne

J. Varje

Aalto-Yliopisto

Taina Kurki-Suonio

Chalmers, Fysik, Subatomär fysik och plasmafysik

Plasma Physics and Controlled Fusion

0741-3335 (ISSN) 1361-6587 (eISSN)

Vol. 58 12

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1088/0741-3335/58/12/125017

Mer information

Senast uppdaterat

2018-05-03