Regarding the optimization of O1-mode ECRH and the feasibility of EBW startup on NSTX-U

Lopez, Nicolas; Poli, Francesca M.

doi:10.1088/1361-6587/aabaa8

Title: Regarding the optimization of O1-mode ECRH and the feasibility of EBW startup on NSTX-U

Journal Article · Thu Mar 29 00:00:00 EDT 2018 · Plasma Physics and Controlled Fusion

DOI:https://doi.org/10.1088/1361-6587/aabaa8· OSTI ID:1432061

^[1];

^[2]

Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Recently published scenarios for fully non-inductive startup and operation on the National Spherical Torus eXperiment Upgrade (NSTX-U) [Menard J et al 2012 Nucl. Fusion 52 083015] show Electron Cyclotron Resonance Heating (ECRH) as an important component in preparing a target plasma for efficient High Harmonic Fast Wave and Neutral Beam heating. The modelling of the propagation and absorption of EC waves in the evolving plasma is required to define the most effective window of operation, and to optimize the launcher geometry for maximal heating and current drive during this window. Here in this paper, we extend a previous optimization of O1-mode ECRH on NSTX-U to account for the full time-dependent performance of the ECRH using simulations performed with TRANSP. We find that the evolution of the density profile has a prominent role in the optimization by defining the time window of operation, which in certain cases may be a more important metric to compare launcher performance than the average power absorption. This feature cannot be captured by analysis on static profiles, and should be accounted for when optimizing ECRH on any device that operates near the cutoff density. Additionally, the utility of the electron Bernstein wave (EBW) in driving current and generating closed flux surfaces in the early startup phase has been demonstrated on a number of devices. Using standalone GENRAY simulations, we find that efficient EBW current drive is possible on NSTX-U if the injection angle is shifted below the midplane and aimed towards the top half of the vacuum vessel. However, collisional damping of the EBW is projected to be significant, in some cases accounting for up to 97\% of the absorbed EBW power.

View Accepted Manuscript (DOE)

Cite

Export

Save

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 1432061

Journal Information:: Plasma Physics and Controlled Fusion, Vol. 60, Issue 6; ISSN 0741-3335

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

Citation Metrics:

Cited by: 7 works

Citation information provided by
Web of Science

References (39)

Features of spherical torus plasmas Peng, Y-K. M.; Strickler, D. J. Nuclear Fusion, Vol. 26, Issue 6 https://doi.org/10.1088/0029-5515/26/6/005	journal	June 1986
Overview of the physics and engineering design of NSTX upgrade Menard, J. E.; Gerhardt, S.; Bell, M. Nuclear Fusion, Vol. 52, Issue 8 https://doi.org/10.1088/0029-5515/52/8/083015	journal	July 2012
A component test facility based on the spherical tokamak Peng, Y-K M.; Fogarty, P. J.; Burgess, T. W. Plasma Physics and Controlled Fusion, Vol. 47, Issue 12B https://doi.org/10.1088/0741-3335/47/12B/S20	journal	November 2005
Remote Handling and Plasma Conditions to Enable Fusion Nuclear Science R&D Using a Component Testing Facility Peng, Y. K. M.; Burgess, T. W.; Carroll, A. J. Fusion Science and Technology, Vol. 56, Issue 2 https://doi.org/10.13182/FST09-A9034	journal	August 2009
Fusion–Fission Transmutation Scheme—Efficient destruction of nuclear waste Kotschenreuther, M.; Valanju, P. M.; Mahajan, S. M. Fusion Engineering and Design, Vol. 84, Issue 1 https://doi.org/10.1016/j.fusengdes.2008.11.019	journal	January 2009
Research on fusion neutron sources Gryaznevich, M. P. FUSION FOR NEUTRONS AND SUBCRITICAL NUCLEAR FISSION: Proceedings of the International Conference, AIP Conference Proceedings https://doi.org/10.1063/1.4729452	conference	January 2012
Electron Bernstein wave current drive in the start-up phase of a Tokamak discharge Montes, A.; Ludwig, G. O. Plasma Physics and Controlled Fusion, Vol. 28, Issue 12A https://doi.org/10.1088/0741-3335/28/12A/003	journal	December 1986
Electron Bernstein wave heating and diagnostic Laqua, Heinrich Peter Plasma Physics and Controlled Fusion, Vol. 49, Issue 4 https://doi.org/10.1088/0741-3335/49/4/R01	journal	March 2007
Electron Bernstein wave assisted plasma current start-up in MAST Shevchenko, V. F.; O'Brien, M. R.; Taylor, D. Nuclear Fusion, Vol. 50, Issue 2 https://doi.org/10.1088/0029-5515/50/2/022004	journal	January 2010
Long Pulse EBW Start-up Experiments in MAST Shevchenko, V. F.; Baranov, Y. F.; Bigelow, T. EPJ Web of Conferences, Vol. 87 https://doi.org/10.1051/epjconf/20158702007	journal	January 2015
Plasma production by low-field side injection of electron cyclotron waves in a simple magnetized torus Podestà, M.; Fasoli, A.; Labit, B. Plasma Physics and Controlled Fusion, Vol. 47, Issue 11 https://doi.org/10.1088/0741-3335/47/11/008	journal	October 2005
Experimental characterization and modelling of the particle source in an Electron-Cyclotron wave driven toroidal plasma Podestà, M.; Fasoli, A.; Labit, B. Plasma Physics and Controlled Fusion, Vol. 48, Issue 8 https://doi.org/10.1088/0741-3335/48/8/001	journal	July 2006
ECRH-assisted plasma start-up with toroidally inclined launch: multi-machine comparison and perspectives for ITER Stober, J.; Jackson, G. L.; Ascasibar, E. Nuclear Fusion, Vol. 51, Issue 8 https://doi.org/10.1088/0029-5515/51/8/083031	journal	July 2011
A megawatt-level 28 GHz heating system for the National Spherical Torus Experiment Upgrade Taylor, G.; Ellis, R. A.; Fredd, E. EPJ Web of Conferences, Vol. 87 https://doi.org/10.1051/epjconf/20158702013	journal	January 2015
An Empirical Approach to Tokamak Transport Hawryluk, R. J. Physics of Plasmas Close to Thermonuclear Conditions, p. 19-46 https://doi.org/10.1016/B978-1-4832-8385-2.50009-1	book	January 1979
ECRH/EBWH system for NSTX-U Taylor, G.; Ellis, R. A.; Harvey, R. W. EPJ Web of Conferences, Vol. 32 https://doi.org/10.1051/epjconf/20123202014	journal	January 2012
Physics basis of Multi-Mode anomalous transport module Rafiq, T.; Kritz, A. H.; Weiland, J. Physics of Plasmas, Vol. 20, Issue 3 https://doi.org/10.1063/1.4794288	journal	March 2013
Electron cyclotron current drive efficiency in general tokamak geometry Lin-Liu, Y. R.; Chan, V. S.; Prater, R. Physics of Plasmas, Vol. 10, Issue 10 https://doi.org/10.1063/1.1610472	journal	October 2003
Electron cyclotron current drive in low collisionality limit: On parallel momentum conservation Marushchenko, N. B.; Beidler, C. D.; Kasilov, S. V. Physics of Plasmas, Vol. 18, Issue 3 https://doi.org/10.1063/1.3558584	journal	March 2011
Ray Tracing and Beyond Tracy, E. R.; Brizard, A. J.; Richardson, A. S. Cambridge University Press https://doi.org/10.1017/CBO9780511667565	book	January 2014
Electron cyclotron resonance heating and current drive in toroidal fusion plasmas Erckmann, V.; Gasparino, U. Plasma Physics and Controlled Fusion, Vol. 36, Issue 12 https://doi.org/10.1088/0741-3335/36/12/001	journal	December 1994
Gradient-index optics: a review Moore, Duncan T. Applied Optics, Vol. 19, Issue 7 https://doi.org/10.1364/AO.19.001035	journal	January 1980
Semiclassical description of scattering Ford, Kenneth W.; Wheeler, John A. Annals of Physics, Vol. 7, Issue 3 https://doi.org/10.1016/0003-4916(59)90026-0	journal	July 1959
Spontaneous Formation of Closed-Field Torus Equilibrium via Current Jump Observed in an Electron-Cyclotron-Heated Plasma Yoshinaga, T.; Uchida, M.; Tanaka, H. Physical Review Letters, Vol. 96, Issue 12 https://doi.org/10.1103/PhysRevLett.96.125005	journal	March 2006
A current profile model for magnetic analysis of the start-up phase of toroidal plasmas driven by electron cyclotron heating and current drive Yoshinaga, T.; Uchida, M.; Tanaka, H. Nuclear Fusion, Vol. 47, Issue 3 https://doi.org/10.1088/0029-5515/47/3/007	journal	February 2007
Open field equilibrium current and cross-field passing electrons as an initiator of a closed flux surface in EC-heated toroidal plasmas Maekawa, T.; Yoshinaga, T.; Uchida, M. Nuclear Fusion, Vol. 52, Issue 8 https://doi.org/10.1088/0029-5515/52/8/083008	journal	July 2012
Off-midplane launch of electron Bernstein waves for current drive in overdense plasmas Forest, C. B.; Chattopadhyay, P. K.; Harvey, R. W. Physics of Plasmas, Vol. 7, Issue 5 https://doi.org/10.1063/1.873951	journal	May 2000
Electron Bernstein wave simulations and comparison to preliminary NSTX emission data Preinhaelter, Josef; Urban, Jakub; Pavlo, Pavol Review of Scientific Instruments, Vol. 77, Issue 10 https://doi.org/10.1063/1.2336467	journal	October 2006
Collisional Damping of Electron Bernstein Waves and its Mitigation by Evaporated Lithium Conditioning in Spherical-Tokamak Plasmas Diem, S. J.; Taylor, G.; Caughman, J. B. Physical Review Letters, Vol. 103, Issue 1 https://doi.org/10.1103/PhysRevLett.103.015002	journal	June 2009
Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime Sauter, O.; Angioni, C.; Lin-Liu, Y. R. Physics of Plasmas, Vol. 6, Issue 7 https://doi.org/10.1063/1.873240	journal	July 1999
Modification of the current profile in DIII-D by off-axis electron cyclotron current drive Luce, T. C.; Lin-Liu, Y. R.; Harvey, R. W. Plasma Physics and Controlled Fusion, Vol. 41, Issue 12B https://doi.org/10.1088/0741-3335/41/12B/308	journal	December 1999
Computation of the Spitzer function in stellarators and tokamaks with finite collisionality Kernbichler, Winfried; Kapper, Gernot; Kasilov, Sergei V. EPJ Web of Conferences, Vol. 87 https://doi.org/10.1051/epjconf/20158701006	journal	January 2015
Electron cyclotron current drive simulations for finite collisionality plasmas in Wendelstein 7-X using the full linearized collision model Kapper, Gernot; Kasilov, Sergei V.; Kernbichler, Winfried Physics of Plasmas, Vol. 23, Issue 11 https://doi.org/10.1063/1.4968234	journal	November 2016
Efficient generation of noninductive, off-axis, Ohkawa current, driven by electron Bernstein waves in high β, spherical torus plasmas Taylor, G.; Efthimion, P. C.; Kessel, C. E. Physics of Plasmas, Vol. 11, Issue 10 https://doi.org/10.1063/1.1792635	journal	October 2004
A survey of electron Bernstein wave heating and current drive potential for spherical tokamaks Urban, Jakub; Decker, Joan; Peysson, Yves Nuclear Fusion, Vol. 51, Issue 8 https://doi.org/10.1088/0029-5515/51/8/083050	journal	August 2011
Semiclassical Description of Scattering Ford, Kenneth W.; Wheeler, John A. Annals of Physics, Vol. 281, Issue 1-2 https://doi.org/10.1006/aphy.2000.6018	journal	April 2000
Regarding the optimization of O1-mode ECRH and the feasibility of EBW startup on NSTX-U Lopez, N.; Poli, F. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1562054	dataset	January 2018
Gradient-Index Optics: A Review Moore, Duncan T. 1980 International Lens Design Conference, SPIE Proceedings https://doi.org/10.1117/12.959103	conference	September 1980
Long Pulse EBW Start-up Experiments in MAST Shevchenko, V. F.; Bigelow, T.; Caughman, J. B. arXiv https://doi.org/10.48550/arxiv.1501.01798	text	January 2015

Cited By (2)

Power threshold and saturation of parametric decay instabilities near the upper hybrid resonance in plasmas Hansen, S. K.; Nielsen, S. K.; Stober, J. Physics of Plasmas, Vol. 26, Issue 6 https://doi.org/10.1063/1.5091659	journal	June 2019
Regarding the optimization of O1-mode ECRH and the feasibility of EBW startup on NSTX-U Lopez, N.; Poli, F. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/1562054	dataset	January 2018

Similar Records

Regarding the optimization of O1-mode ECRH and the feasibility of EBW startup on NSTX-U

Dataset · Fri Jun 01 00:00:00 EDT 2018 · OSTI ID:1432061

Lopez, N; Poli, F

ECRH/EBWH SYSTEM FOR NSTX-U

Conference · Tue May 01 00:00:00 EDT 2012 · OSTI ID:1432061

ECRH/EBWH SYSTEM FOR NSTX-

Technical Report · Fri Jun 15 00:00:00 EDT 2012 · OSTI ID:1432061

Taylor, G.; Ellis, R. A.; Harvey, R. W.; +2 more

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Electron Cyclotron
startup
spherical tokamaks

Title: Regarding the optimization of O1-mode ECRH and the feasibility of EBW startup on NSTX-U

Citation Formats

References (39)

Cited By (2)

Similar Records

Related Subjects