Modeling nonstationary, nonaxisymmetric heat patterns in DIIID tokamak
Nonaxisymmetric 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 nonaxisymmetric rotating magnetic perturbation to model the time evolution of the threedimensional magnetic field of a singlenull DIIID tokamak discharge developing a rotating tearing mode. The nonaxiymmetric 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]}
 Univ. of Sao Paulo (Brazil). Dept. of Applied Physics
 General Atomics, San Diego, CA (United States)
 Publication Date:
 Grant/Contract Number:
 FC0204ER54698; SC0012706; FG0205ER54809; 2011/1926911; 2012/180731; 2014/038997
 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 nonstationary, nonaxisymmetric heat patterns in DIIID tokamak", Nucl. Fusion 57, 016017 (2017); Journal ID: ISSN 00295515
 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 05508090, 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
Ciro, D., Evans, T. E., and Caldas, I. L.. Modeling nonstationary, nonaxisymmetric heat patterns in DIIID tokamak. United States: N. p.,
Web. doi:10.1088/00295515/57/1/016017.
Ciro, D., Evans, T. E., & Caldas, I. L.. Modeling nonstationary, nonaxisymmetric heat patterns in DIIID tokamak. United States. doi:10.1088/00295515/57/1/016017.
Ciro, D., Evans, T. E., and Caldas, I. L.. 2016.
"Modeling nonstationary, nonaxisymmetric heat patterns in DIIID tokamak". United States.
doi:10.1088/00295515/57/1/016017. https://www.osti.gov/servlets/purl/1372075.
@article{osti_1372075,
title = {Modeling nonstationary, nonaxisymmetric heat patterns in DIIID tokamak},
author = {Ciro, D. and Evans, T. E. and Caldas, I. L.},
abstractNote = {Nonaxisymmetric 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 nonaxisymmetric rotating magnetic perturbation to model the time evolution of the threedimensional magnetic field of a singlenull DIIID tokamak discharge developing a rotating tearing mode. The nonaxiymmetric 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.},
doi = {10.1088/00295515/57/1/016017},
journal = {Nuclear Fusion},
number = 1,
volume = 57,
place = {United States},
year = {2016},
month = {10}
}