Exploring drift effects in TCV single-null plasmas with the UEDGE code
Abstract
This study explores the effects of particle drifts across the magnetic field in TCV single-null plasmas using the two-dimensional edge plasma transport code UEDGE. In particular, it aims to reproduce a double-peaked density target profile, a feature which has been observed both at JET and in a TCV forward-field ($${\rm{\nabla }}B$$ drift of core ions towards the X-point) discharge. Initial simulations are performed with drift effects turned off. This allows identification of the input parameters that strongly influence the computed steady-state but are not well known from the experiment. Including cross-field drifts self-consistently in the simulations brings computed profiles at the inner target closer to the experiment, with the double peak being reproduced for the density. In agreement with the experiment, simulations of a similar reversed-field shot yield lower n e and higher T e at the inner target, as well as unchanged temperatures at the outer plate. However, several discrepancies remain. In the forward field case, the inner target density peak near the separatrix is much sharper than seen experimentally. Furthermore, simulations show a strong dependence of the outer plate density and of the outer/inner power sharing on toroidal field direction. Experimentally, no such dependencies are observed. In the simulations, the changes of target profiles with field direction are mainly due to E × B drifts in the divertor region. Finally, while these simulations highlight the importance of E × B drifts in these TCV plasmas, the remaining differences with the experiment indicate that their role is overestimated in the simulations.
- Authors:
-
- École Polytechnique Fédérale de Lausanne (EPFL) (Switzlerland). Swiss Plasma Center (SPC); Univ. of Oxford (United Kingdom). Rudolf Peierls Centre for Theoretical Physics
- École Polytechnique Fédérale de Lausanne (EPFL) (Switzlerland). Swiss Plasma Center (SPC)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); École Polytechnique Fédérale de Lausanne (EPFL) (Switzlerland)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1465288
- Report Number(s):
- LLNL-JRNL-746959
Journal ID: ISSN 0741-3335; 931709; TRN: US1902463
- Grant/Contract Number:
- AC52-07NA27344
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Plasma Physics and Controlled Fusion
- Additional Journal Information:
- Journal Volume: 59; Journal Issue: 10; Journal ID: ISSN 0741-3335
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TCV; UEDGE; drifts; single-null
Citation Formats
Christen, N., Theiler, C., Rognlien, T. D., Rensink, M. E., Reimerdes, H., Maurizio, R., and Labit, B. Exploring drift effects in TCV single-null plasmas with the UEDGE code. United States: N. p., 2017.
Web. doi:10.1088/1361-6587/aa7c8e.
Christen, N., Theiler, C., Rognlien, T. D., Rensink, M. E., Reimerdes, H., Maurizio, R., & Labit, B. Exploring drift effects in TCV single-null plasmas with the UEDGE code. United States. https://doi.org/10.1088/1361-6587/aa7c8e
Christen, N., Theiler, C., Rognlien, T. D., Rensink, M. E., Reimerdes, H., Maurizio, R., and Labit, B. Thu .
"Exploring drift effects in TCV single-null plasmas with the UEDGE code". United States. https://doi.org/10.1088/1361-6587/aa7c8e. https://www.osti.gov/servlets/purl/1465288.
@article{osti_1465288,
title = {Exploring drift effects in TCV single-null plasmas with the UEDGE code},
author = {Christen, N. and Theiler, C. and Rognlien, T. D. and Rensink, M. E. and Reimerdes, H. and Maurizio, R. and Labit, B.},
abstractNote = {This study explores the effects of particle drifts across the magnetic field in TCV single-null plasmas using the two-dimensional edge plasma transport code UEDGE. In particular, it aims to reproduce a double-peaked density target profile, a feature which has been observed both at JET and in a TCV forward-field (${\rm{\nabla }}B$ drift of core ions towards the X-point) discharge. Initial simulations are performed with drift effects turned off. This allows identification of the input parameters that strongly influence the computed steady-state but are not well known from the experiment. Including cross-field drifts self-consistently in the simulations brings computed profiles at the inner target closer to the experiment, with the double peak being reproduced for the density. In agreement with the experiment, simulations of a similar reversed-field shot yield lower n e and higher T e at the inner target, as well as unchanged temperatures at the outer plate. However, several discrepancies remain. In the forward field case, the inner target density peak near the separatrix is much sharper than seen experimentally. Furthermore, simulations show a strong dependence of the outer plate density and of the outer/inner power sharing on toroidal field direction. Experimentally, no such dependencies are observed. In the simulations, the changes of target profiles with field direction are mainly due to E × B drifts in the divertor region. Finally, while these simulations highlight the importance of E × B drifts in these TCV plasmas, the remaining differences with the experiment indicate that their role is overestimated in the simulations.},
doi = {10.1088/1361-6587/aa7c8e},
journal = {Plasma Physics and Controlled Fusion},
number = 10,
volume = 59,
place = {United States},
year = {Thu Jun 29 00:00:00 EDT 2017},
month = {Thu Jun 29 00:00:00 EDT 2017}
}
Web of Science
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Works referencing / citing this record:
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