Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U

doi:https://doi.org/10.1088/1741-4326/aaa4d0

Title: Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U

Abstract

Here, the upgrade to the National Spherical Torus eXperiment (NSTX-U) included two main improvements: a larger center-stack, enabling higher toroidal field and longer pulse duration, and the addition of three new tangentially aimed neutral beam sources, which increase available heating and current drive, and allow for flexibility in shaping power, torque, current, and particle deposition profiles. To best use these new capabilities and meet the high-performance operational goals of NSTX-U, major upgrades to the NSTX-U control system (NCS) hardware and software have been made. Several control algorithms, including those used for real-time equilibrium reconstruction and shape control, have been upgraded to improve and extend plasma control capabilities. As part of the commissioning phase of first plasma operations, the shape control system was tuned to control the boundary in both inner-wall limited and diverted discharges. It has been used to accurately track the requested evolution of the boundary (including the size of the inner gap between the plasma and central solenoid, which is a challenge for the ST configuration), X-point locations, and strike point locations, enabling repeatable discharge evolutions for scenario development and diagnostic commissioning.

Authors:

^[1];

^[1]; Mueller, D. ^[1];

^[2]; Erickson, K. ^[1]; Ferron, J. ^[2]; Gates, D. A. ^[1]; Gerhardt, S. ^[1]; Johnson, R. ^[2]; Kolemen, E. ^[3];

^[1];

^[1]; Sabbagh, S. A. ^[4]; Scotti, F. ^[5]; Vail, P. ^[3]

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
General Atomics, San Diego, CA (United States)
Princeton Univ., Princeton, NJ (United States)
Columbia Univ., New York, NY (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:: 2018-01-25

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1419785

Report Number(s):: PPPL-5441
Journal ID: ISSN 0029-5515; TRN: US1801392

Grant/Contract Number:: AC02-09CH11466

Resource Type:: Journal Article: Accepted Manuscript

Journal Name:: Nuclear Fusion

Additional Journal Information:: Journal Volume: 58; Journal Issue: 3; Journal ID: ISSN 0029-5515

Publisher:: IOP Science

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; spherical torus; plasma boundary control; plasma boundary reconstruction; MIMO feedback control

Citation Formats


                    Boyer, M. D., Battaglia, D. J., Mueller, D., Eidietis, N., Erickson, K., Ferron, J., Gates, D. A., Gerhardt, S., Johnson, R., Kolemen, E., Menard, J., Myers, C. E., Sabbagh, S. A., Scotti, F., and Vail, P. Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U.  United States: N. p., 2018. 
        Web.  doi:10.1088/1741-4326/aaa4d0.

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                    Boyer, M. D., Battaglia, D. J., Mueller, D., Eidietis, N., Erickson, K., Ferron, J., Gates, D. A., Gerhardt, S., Johnson, R., Kolemen, E., Menard, J., Myers, C. E., Sabbagh, S. A., Scotti, F., & Vail, P. Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U.  United States.  https://doi.org/10.1088/1741-4326/aaa4d0

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                    Boyer, M. D., Battaglia, D. J., Mueller, D., Eidietis, N., Erickson, K., Ferron, J., Gates, D. A., Gerhardt, S., Johnson, R., Kolemen, E., Menard, J., Myers, C. E., Sabbagh, S. A., Scotti, F., and Vail, P. Thu .  
        "Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U".  United States.  https://doi.org/10.1088/1741-4326/aaa4d0.  https://www.osti.gov/servlets/purl/1419785.

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@article{osti_1419785,

  title        = {Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U},

  author       = {Boyer, M. D. and Battaglia, D. J. and Mueller, D. and Eidietis, N. and Erickson, K. and Ferron, J. and Gates, D. A. and Gerhardt, S. and Johnson, R. and Kolemen, E. and Menard, J. and Myers, C. E. and Sabbagh, S. A. and Scotti, F. and Vail, P.},

  abstractNote = {Here, the upgrade to the National Spherical Torus eXperiment (NSTX-U) included two main improvements: a larger center-stack, enabling higher toroidal field and longer pulse duration, and the addition of three new tangentially aimed neutral beam sources, which increase available heating and current drive, and allow for flexibility in shaping power, torque, current, and particle deposition profiles. To best use these new capabilities and meet the high-performance operational goals of NSTX-U, major upgrades to the NSTX-U control system (NCS) hardware and software have been made. Several control algorithms, including those used for real-time equilibrium reconstruction and shape control, have been upgraded to improve and extend plasma control capabilities. As part of the commissioning phase of first plasma operations, the shape control system was tuned to control the boundary in both inner-wall limited and diverted discharges. It has been used to accurately track the requested evolution of the boundary (including the size of the inner gap between the plasma and central solenoid, which is a challenge for the ST configuration), X-point locations, and strike point locations, enabling repeatable discharge evolutions for scenario development and diagnostic commissioning.},

  doi          = {10.1088/1741-4326/aaa4d0},

  url          = {https://www.osti.gov/biblio/1419785},
  journal      = {Nuclear Fusion},

  issn         = {0029-5515},

  number       = 3,

  volume       = 58,

  place        = {United States},

  year         = {2018},

  month        = {1}

}

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Works referencing / citing this record:

Real-time capable modeling of neutral beam injection on NSTX-U using neural networks
journal, March 2019

Boyer, M. D.; Kaye, S.; Erickson, K.
Nuclear Fusion, Vol. 59, Issue 5
https://doi.org/10.1088/1741-4326/ab0762

Real-time capable modeling of neutral beam injection on NSTX-U using neural networks
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Boyer, M. D.; Kaye, S.; Erickson, K.
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Effect of sawtooth crashes on fast ion distribution in NSTX-U
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Title: Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U

Abstract

Citation Formats

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Equilibrium properties of spherical torus plasmas in NSTX journal, November 2001

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus Experiment divertor journal, October 2012

Multivariable Multi-model-based magnetic control system for the current ramp-up phase in the National Spherical Torus Experiment (NSTX) conference, December 2011

Real-time capable modeling of neutral beam injection on NSTX-U using neural networks journal, March 2019

Real-time capable modeling of neutral beam injection on NSTX-U using neural networks journal, March 2019

A scalable real-time framework for Thomson scattering analysis: Application to NSTX-U journal, April 2019

Design and simulation of the snowflake divertor control for NSTX–U journal, January 2019

Initial development of the DIII–D snowflake divertor control journal, April 2018

Effect of sawtooth crashes on fast ion distribution in NSTX-U journal, July 2018

Divertor leg filaments in NSTX-U journal, October 2018

Overview of the physics and engineering design of NSTX upgrade
journal, July 2012

Overview of NSTX Upgrade initial results and modelling highlights
journal, June 2017

Exploration of spherical torus physics in the NSTX device
journal, March 2000

First results from MAST
journal, October 2001

Fusion nuclear science facilities and pilot plants based on the spherical tokamak
journal, August 2016

Prospects for pilot plants based on the tokamak, spherical tokamak and stellarator
journal, August 2011

An overview of recent physics results from NSTX
journal, March 2015

Energy confinement scaling in the low aspect ratio National Spherical Torus Experiment (NSTX)
journal, August 2006

Scaling of Electron and Ion Transport in the High-Power Spherical Torus NSTX
journal, April 2007

Confinement and local transport in the National Spherical Torus Experiment (NSTX)
journal, June 2007

Collisionality and safety factor scalings of H-mode energy transport in the MAST spherical tokamak
journal, June 2011

Collective fast ion instability-induced losses in National Spherical Tokamak Experiment
journal, May 2006

Recent experiments on Alfvén eigenmodes in MAST
journal, June 2008

Experimental studies on fast-ion transport by Alfvén wave avalanches on the National Spherical Torus Experiment
journal, May 2009

Modeling fast-ion transport during toroidal Alfvén eigenmode avalanches in National Spherical Torus Experiment
journal, December 2009

Progress towards steady state at low aspect ratio on the National Spherical Torus Experiment (NSTX)
journal, September 2007

Overview of recent physics results from the National Spherical Torus Experiment (NSTX)
journal, September 2007

Overview of results from the National Spherical Torus Experiment (NSTX)
journal, September 2009

Stability at high performance in the MAST spherical tokamak
journal, August 2004

Macroscopic stability of high β MAST plasmas
journal, June 2011

Digital Coil Protection System (DCPS) algorithms for the NSTX centerstack upgrade
conference, June 2011

NSTX-U Digital Coil Protection System Software Detailed Design
journal, June 2014

Plasma shape control on the National Spherical Torus Experiment (NSTX) using real-time equilibrium reconstruction
journal, December 2005

Implementation of β _N Control in the National Spherical Torus Experiment
journal, January 2012

Strike point control for the National Spherical Torus Experiment (NSTX)
journal, September 2010

Plasma modelling results and shape control improvements for NSTX
journal, November 2011

Feedback control design for non-inductively sustained scenarios in NSTX-U using TRANSP
journal, April 2017

Simultaneous feedback control of plasma rotation and stored energy on NSTX-U using neoclassical toroidal viscosity and neutral beam injection
journal, May 2017

Model predictive control with integral action for the rotational transform profile tracking in NSTX-U
conference, September 2016

Modeling and control of plasma rotation for NSTX using neoclassical toroidal viscosity and neutral beam injection
journal, February 2016

A reduced resistive wall mode kinetic stability model for disruption forecasting
journal, May 2017

Magnetic diagnostics for equilibrium reconstruction and realtime plasma control in NSTX-Upgrade
journal, November 2014

NSTX-U Control System Upgrades
journal, June 2014

Status of the control system on the National Spherical Torus Experiment (NSTX)
journal, July 2006

A flexible software architecture for tokamak discharge control systems
conference, January 1995

Improved H-mode access in connected DND in MAST
journal, May 2005

Overview of L–H power threshold studies in NSTX
journal, May 2010

Dependence of the L–H transition on X-point geometry and divertor recycling on NSTX
journal, October 2013

Real time equilibrium reconstruction for tokamak discharge control
journal, July 1998

Plasma shape and position control in highly elongated tokamaks
journal, October 1990

Vessel eddy current measurement for the National Spherical Torus Experiment
journal, December 2004

Resistive wall stabilized operation in rotating high beta NSTX plasmas
journal, April 2006

Equilibrium properties of spherical torus plasmas in NSTX
journal, November 2001

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus Experiment divertor
journal, October 2012

Multivariable Multi-model-based magnetic control system for the current ramp-up phase in the National Spherical Torus Experiment (NSTX)
conference, December 2011

Real-time capable modeling of neutral beam injection on NSTX-U using neural networks
journal, March 2019

Real-time capable modeling of neutral beam injection on NSTX-U using neural networks
journal, March 2019

A scalable real-time framework for Thomson scattering analysis: Application to NSTX-U
journal, April 2019

Design and simulation of the snowflake divertor control for NSTX–U
journal, January 2019

Initial development of the DIII–D snowflake divertor control
journal, April 2018

Effect of sawtooth crashes on fast ion distribution in NSTX-U
journal, July 2018

Divertor leg filaments in NSTX-U
journal, October 2018