skip to main content

DOE PAGESDOE PAGES

Title: Modeling non-stationary, non-axisymmetric heat patterns in DIII-D tokamak

Non-axisymmetric stationary magnetic perturbations lead to the formation of homoclinic tangles near the divertor magnetic saddle in tokamak discharges. These tangles intersect the divertor plates in static helical structures that delimit the regions reached by open magnetic field lines reaching the plasma column and leading the charged particles to the strike surfaces by parallel transport. In this article we introduce a non-axisymmetric rotating magnetic perturbation to model the time evolution of the three-dimensional magnetic field of a singlenull DIII-D tokamak discharge developing a rotating tearing mode. The non-axiymmetric field is modeled using the magnetic signals to adjust the phases and currents of a set of internal filamentary currents that approximate the magnetic field in the plasma edge region. The stable and unstable manifolds of the asymmetric magnetic saddle are obtained through an adaptive calculation providing the cuts at a given poloidal plane and the strike surfaces. Lastly, for the modeled shot, the experimental heat pattern and its time development are well described by the rotating unstable manifold, indicating the emergence of homoclinic lobes in a rotating frame due to the plasma instabilities.
Authors:
 [1] ;  [2] ;  [1]
  1. Univ. of Sao Paulo (Brazil). Dept. of Applied Physics
  2. General Atomics, San Diego, CA (United States)
Publication Date:
Grant/Contract Number:
FC02-04ER54698; SC0012706; FG02-05ER54809; 2011/19269-11; 2012/18073-1; 2014/03899-7
Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 57; Journal Issue: 1; Related Information: D. Ciro, T.E. Evans, I.L. Caldas, "Modeling non-stationary, non-axisymmetric heat patterns in DIII-D tokamak", Nucl. Fusion 57, 016017 (2017); Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Research Org:
General Atomics, San Diego, CA (United States)
Sponsoring Org:
USDOE
Contributing Orgs:
Department of Applied Physics, São Paulo University, São Paulo, CEP 05508-090, Brazil
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 3D magnetic perturbations; separatrix splitting; divertor heat flux; MHD current filaments; helical divertor footprints
OSTI Identifier:
1372075
Alternate Identifier(s):
OSTI ID: 1330113