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Title: Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade

Abstract

The National Spherical Torus Experiment Upgrade (NSTX-U) will advance the physics basis required for achieving steady-state, high-beta, and high-confinement conditions in a tokamak by accessing high toroidal field (1 T) and plasma current (1.0 - 2.0 MA) in a low aspect ratio geometry (A = 1.6 - 1.8) with flexible auxiliary heating systems (12 MW NBI, 6 MW HHFW). This paper describes progress in the development of L- and Hmode discharge scenarios and the commissioning of operational tools in the first ten weeks of operation that enable the scientific mission of NSTX-U. Vacuum field calculations completed prior to operations supported the rapid development and optimization of inductive breakdown at different values of ohmic solenoid current. The toroidal magnetic field (BT0 = 0.65 T) exceeded the maximum values achieved on NSTX and novel long-pulse L-mode discharges with regular sawtooth activity exceeded the longest pulses produced on NSTX (tpulse > 1.8s). The increased flux of the central solenoid facilitated the development of stationary L-mode discharges over a range of density and plasma current (Ip). H-mode discharges achieved similar levels of stored energy, confinement (H98y,2 > 1) and stability (βN/βN-nowall > 1) compared to NSTX discharges for Ip ≤ 1 MA. High-performance H-modemore » scenarios require an L-H transition early in the Ip ramp-up phase in order to obtain low internal inductance (li) throughout the discharge, which is conducive to maintaining vertical stability at high elongation (κ > 2.2) and achieving long periods of MHD quiescent operations. The rapid progress in developing L- and H-mode scenarios in support of the scientific program was enabled by advances in real-time plasma control, efficient error field identification and correction, effective conditioning of the graphite wall and excellent diagnostic availability.« less

Authors:
ORCiD logo [1]; ORCiD logo [1];  [1];  [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [2];  [3];  [4];  [1];  [2];  [1];  [1];  [1];  [1];  [1];  [1];  [1]; ORCiD logo [1] more »;  [5];  [3] « less
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Columbia Univ., New York, NY (United States)
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  4. Univ. of Illinois, Urbana-Champaign, IL (United States)
  5. Univ. of Washington, Seattle, WA (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
Contributing Org.:
the NSTX-U Research, Operations and Engineering Team
OSTI Identifier:
1425032
Grant/Contract Number:  
AC02-09CH11466
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 4; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Battaglia, D. J., Boyer, M. D., Gerhardt, S., Mueller, D., Myers, C. E., Guttenfelder, W., Menard, J. E., Sabbagh, S. A., Scotti, F., Bedoya, F., Bell, R. E., Berkery, J. W., Diallo, A., Ferraro, N., Kaye, S. M., Jaworski, M. A., LeBlanc, B. P., Ono, M., Park, J. -K., Podesta, M., Raman, R., and Soukhanovskii, V. Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade. United States: N. p., 2018. Web. doi:10.1088/1741-4326/aaa6e0.
Battaglia, D. J., Boyer, M. D., Gerhardt, S., Mueller, D., Myers, C. E., Guttenfelder, W., Menard, J. E., Sabbagh, S. A., Scotti, F., Bedoya, F., Bell, R. E., Berkery, J. W., Diallo, A., Ferraro, N., Kaye, S. M., Jaworski, M. A., LeBlanc, B. P., Ono, M., Park, J. -K., Podesta, M., Raman, R., & Soukhanovskii, V. Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade. United States. doi:10.1088/1741-4326/aaa6e0.
Battaglia, D. J., Boyer, M. D., Gerhardt, S., Mueller, D., Myers, C. E., Guttenfelder, W., Menard, J. E., Sabbagh, S. A., Scotti, F., Bedoya, F., Bell, R. E., Berkery, J. W., Diallo, A., Ferraro, N., Kaye, S. M., Jaworski, M. A., LeBlanc, B. P., Ono, M., Park, J. -K., Podesta, M., Raman, R., and Soukhanovskii, V. Tue . "Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade". United States. doi:10.1088/1741-4326/aaa6e0. https://www.osti.gov/servlets/purl/1425032.
@article{osti_1425032,
title = {Scenario development during commissioning operations on the National Spherical Torus Experiment Upgrade},
author = {Battaglia, D. J. and Boyer, M. D. and Gerhardt, S. and Mueller, D. and Myers, C. E. and Guttenfelder, W. and Menard, J. E. and Sabbagh, S. A. and Scotti, F. and Bedoya, F. and Bell, R. E. and Berkery, J. W. and Diallo, A. and Ferraro, N. and Kaye, S. M. and Jaworski, M. A. and LeBlanc, B. P. and Ono, M. and Park, J. -K. and Podesta, M. and Raman, R. and Soukhanovskii, V.},
abstractNote = {The National Spherical Torus Experiment Upgrade (NSTX-U) will advance the physics basis required for achieving steady-state, high-beta, and high-confinement conditions in a tokamak by accessing high toroidal field (1 T) and plasma current (1.0 - 2.0 MA) in a low aspect ratio geometry (A = 1.6 - 1.8) with flexible auxiliary heating systems (12 MW NBI, 6 MW HHFW). This paper describes progress in the development of L- and Hmode discharge scenarios and the commissioning of operational tools in the first ten weeks of operation that enable the scientific mission of NSTX-U. Vacuum field calculations completed prior to operations supported the rapid development and optimization of inductive breakdown at different values of ohmic solenoid current. The toroidal magnetic field (BT0 = 0.65 T) exceeded the maximum values achieved on NSTX and novel long-pulse L-mode discharges with regular sawtooth activity exceeded the longest pulses produced on NSTX (tpulse > 1.8s). The increased flux of the central solenoid facilitated the development of stationary L-mode discharges over a range of density and plasma current (Ip). H-mode discharges achieved similar levels of stored energy, confinement (H98y,2 > 1) and stability (βN/βN-nowall > 1) compared to NSTX discharges for Ip ≤ 1 MA. High-performance H-mode scenarios require an L-H transition early in the Ip ramp-up phase in order to obtain low internal inductance (li) throughout the discharge, which is conducive to maintaining vertical stability at high elongation (κ > 2.2) and achieving long periods of MHD quiescent operations. The rapid progress in developing L- and H-mode scenarios in support of the scientific program was enabled by advances in real-time plasma control, efficient error field identification and correction, effective conditioning of the graphite wall and excellent diagnostic availability.},
doi = {10.1088/1741-4326/aaa6e0},
journal = {Nuclear Fusion},
number = 4,
volume = 58,
place = {United States},
year = {2018},
month = {2}
}

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Works referenced in this record:

Scenario Development During Commissioning Operations on the National Spherical Torus Experiment Upgrade
dataset, January 2018

  • Battaglia, D.; Boyer, M.; Gerhardt, S.
  • Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
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Feedback control design for non-inductively sustained scenarios in NSTX-U using TRANSP
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Suppression of Alfvén Modes on the National Spherical Torus Experiment Upgrade with Outboard Beam Injection
journal, June 2017


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

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  • DOI: 10.1088/1741-4326/aa600a

Advances in global MHD mode stabilization research on NSTX
journal, January 2010


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

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  • DOI: 10.1063/1.4889781

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


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


Prospects for the Thomson scattering system on NSTX-Upgrade
journal, October 2012

  • Diallo, A.; LeBlanc, B. P.; Labik, G.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4740267

Comparison of poloidal velocity measurements to neoclassical theory on the National Spherical Torus Experiment
journal, August 2010

  • Bell, R. E.; Andre, R.; Kaye, S. M.
  • Physics of Plasmas, Vol. 17, Issue 8
  • DOI: 10.1063/1.3478571

Edge rotation and temperature diagnostic on the National Spherical Torus Experiment
journal, March 2004

  • Biewer, T. M.; Bell, R. E.; Feder, R.
  • Review of Scientific Instruments, Vol. 75, Issue 3
  • DOI: 10.1063/1.1646740

A real-time velocity diagnostic for NSTX
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Measurement of poloidal velocity on the National Spherical Torus Experiment (invited)
journal, October 2010

  • Bell, Ronald E.; Feder, Russell
  • Review of Scientific Instruments, Vol. 81, Issue 10
  • DOI: 10.1063/1.3485027

Electron density measurements in the National Spherical Torus Experiment detached divertor region using Stark broadening of deuterium infrared Paschen emission lines
journal, October 2006

  • Soukhanovskii, V. A.; Johnson, D. W.; Kaita, R.
  • Review of Scientific Instruments, Vol. 77, Issue 10
  • DOI: 10.1063/1.2336456

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

  • Scotti, Filippo; Roquemore, A. L.; Soukhanovskii, V. A.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4739510

A dual wavelength imaging system for plasma-surface interaction studies on the National Spherical Torus Experiment Upgrade
journal, December 2015

  • Scotti, F.; Soukhanovskii, V. A.
  • Review of Scientific Instruments, Vol. 86, Issue 12
  • DOI: 10.1063/1.4935609

Compact “diode-based” multi-energy soft x-ray diagnostic for NSTX
journal, October 2012

  • Tritz, K.; Clayton, D. J.; Stutman, D.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4731741

Transmission grating based extreme ultraviolet imaging spectrometer for time and space resolved impurity measurements
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  • Kumar, Deepak; Stutman, Dan; Tritz, Kevin
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  • DOI: 10.1063/1.3474661

Spectroscopic diagnostics for liquid lithium divertor studies on National Spherical Torus Experiment
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  • Review of Scientific Instruments, Vol. 81, Issue 10
  • DOI: 10.1063/1.3478749

Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)
journal, September 2016

  • Vann, R. G. L.; Brunner, K. J.; Ellis, R.
  • Review of Scientific Instruments, Vol. 87, Issue 11
  • DOI: 10.1063/1.4962253

Three new extreme ultraviolet spectrometers on NSTX-U for impurity monitoring
journal, August 2016

  • Weller, M. E.; Beiersdorfer, P.; Soukhanovskii, V. A.
  • Review of Scientific Instruments, Vol. 87, Issue 11
  • DOI: 10.1063/1.4960755

Midplane neutral density profiles in the National Spherical Torus Experiment
journal, August 2015

  • Stotler, D. P.; Scotti, F.; Bell, R. E.
  • Physics of Plasmas, Vol. 22, Issue 8
  • DOI: 10.1063/1.4928372

Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade
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Advances in boronization on NSTX-Upgrade
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Progress in understanding error-field physics in NSTX spherical torus plasmas
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Status of the control system on the National Spherical Torus Experiment (NSTX)
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Plasma boundary shape control and real-time equilibrium reconstruction on NSTX-U
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Real time equilibrium reconstruction for tokamak discharge control
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Multi-region approach to free-boundary three-dimensional tokamak equilibria and resistive wall instabilities
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Energy confinement scaling in the low aspect ratio National Spherical Torus Experiment (NSTX)
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    Works referencing / citing this record:

    Preliminary measurements of the edge magnetic field pitch from 2-D Doppler backscattering in MAST and NSTX-U (invited)
    journal, September 2016

    • Vann, R. G. L.; Brunner, K. J.; Ellis, R.
    • Review of Scientific Instruments, Vol. 87, Issue 11
    • DOI: 10.1063/1.4962253

    Comparison of poloidal velocity measurements to neoclassical theory on the National Spherical Torus Experiment
    journal, August 2010

    • Bell, R. E.; Andre, R.; Kaye, S. M.
    • Physics of Plasmas, Vol. 17, Issue 8
    • DOI: 10.1063/1.3478571

    A real-time velocity diagnostic for NSTX
    journal, March 2012

    • Podestà, M.; Bell, R. E.
    • Review of Scientific Instruments, Vol. 83, Issue 3
    • DOI: 10.1063/1.3692752

    Multi-region approach to free-boundary three-dimensional tokamak equilibria and resistive wall instabilities
    journal, May 2016

    • Ferraro, N. M.; Jardin, S. C.; Lao, L. L.
    • Physics of Plasmas, Vol. 23, Issue 5
    • DOI: 10.1063/1.4948722

    NSTX-U Digital Coil Protection System Software Detailed Design
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    Three new extreme ultraviolet spectrometers on NSTX-U for impurity monitoring
    journal, August 2016

    • Weller, M. E.; Beiersdorfer, P.; Soukhanovskii, V. A.
    • Review of Scientific Instruments, Vol. 87, Issue 11
    • DOI: 10.1063/1.4960755

    Snowflake Divertor Experiments in the DIII-D, NSTX, and NSTX-U Tokamaks Aimed at the Development of the Divertor Power Exhaust Solution
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    • Soukhanovskii, V. A.; Allen, S. L.; Fenstermacher, M. E.
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    A reduced resistive wall mode kinetic stability model for disruption forecasting
    journal, May 2017

    • Berkery, J. W.; Sabbagh, S. A.; Bell, R. E.
    • Physics of Plasmas, Vol. 24, Issue 5
    • DOI: 10.1063/1.4977464

    Electron density measurements in the National Spherical Torus Experiment detached divertor region using Stark broadening of deuterium infrared Paschen emission lines
    journal, October 2006

    • Soukhanovskii, V. A.; Johnson, D. W.; Kaita, R.
    • Review of Scientific Instruments, Vol. 77, Issue 10
    • DOI: 10.1063/1.2336456

    Prospects for the Thomson scattering system on NSTX-Upgrade
    journal, October 2012

    • Diallo, A.; LeBlanc, B. P.; Labik, G.
    • Review of Scientific Instruments, Vol. 83, Issue 10
    • DOI: 10.1063/1.4740267

    A dual wavelength imaging system for plasma-surface interaction studies on the National Spherical Torus Experiment Upgrade
    journal, December 2015

    • Scotti, F.; Soukhanovskii, V. A.
    • Review of Scientific Instruments, Vol. 86, Issue 12
    • DOI: 10.1063/1.4935609

    Edge rotation and temperature diagnostic on the National Spherical Torus Experiment
    journal, March 2004

    • Biewer, T. M.; Bell, R. E.; Feder, R.
    • Review of Scientific Instruments, Vol. 75, Issue 3
    • DOI: 10.1063/1.1646740

    Computation of three-dimensional tokamak and spherical torus equilibria
    journal, May 2007

    • Park, Jong-kyu; Boozer, Allen H.; Glasser, Alan H.
    • Physics of Plasmas, Vol. 14, Issue 5
    • DOI: 10.1063/1.2732170

    Measurement of poloidal velocity on the National Spherical Torus Experiment (invited)
    journal, October 2010

    • Bell, Ronald E.; Feder, Russell
    • Review of Scientific Instruments, Vol. 81, Issue 10
    • DOI: 10.1063/1.3485027

    Compact and multi-view solid state neutral particle analyzer arrays on National Spherical Torus Experiment-Upgrade
    journal, July 2016

    • Liu, D.; Heidbrink, W. W.; Tritz, K.
    • Review of Scientific Instruments, Vol. 87, Issue 11
    • DOI: 10.1063/1.4959798

    NSTX-U Control System Upgrades
    journal, June 2014


    Transmission grating based extreme ultraviolet imaging spectrometer for time and space resolved impurity measurements
    journal, October 2010

    • Kumar, Deepak; Stutman, Dan; Tritz, Kevin
    • Review of Scientific Instruments, Vol. 81, Issue 10
    • DOI: 10.1063/1.3474661

    Dependence of recycling and edge profiles on lithium evaporation in high triangularity, high performance NSTX H-mode discharges
    journal, August 2015


    Compact “diode-based” multi-energy soft x-ray diagnostic for NSTX
    journal, October 2012

    • Tritz, K.; Clayton, D. J.; Stutman, D.
    • Review of Scientific Instruments, Vol. 83, Issue 10
    • DOI: 10.1063/1.4731741

    Spectroscopic diagnostics for liquid lithium divertor studies on National Spherical Torus Experiment
    journal, October 2010

    • Soukhanovskii, V. A.; Roquemore, A. L.; Bell, R. E.
    • Review of Scientific Instruments, Vol. 81, Issue 10
    • DOI: 10.1063/1.3478749

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

    • Scotti, Filippo; Roquemore, A. L.; Soukhanovskii, V. A.
    • Review of Scientific Instruments, Vol. 83, Issue 10
    • DOI: 10.1063/1.4739510

    Scenario Development During Commissioning Operations on the National Spherical Torus Experiment Upgrade
    dataset, January 2018

    • Battaglia, D.; Boyer, M.; Gerhardt, S.
    • Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
    • DOI: 10.11578/1562052

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

    • Gerhardt, S. P.; Erickson, K.; Kaita, R.
    • Review of Scientific Instruments, Vol. 85, Issue 11
    • DOI: 10.1063/1.4889781

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


    Midplane neutral density profiles in the National Spherical Torus Experiment
    journal, August 2015

    • Stotler, D. P.; Scotti, F.; Bell, R. E.
    • Physics of Plasmas, Vol. 22, Issue 8
    • DOI: 10.1063/1.4928372

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


    Advances in boronization on NSTX-Upgrade
    journal, August 2017


    Error field impact on mode locking and divertor heat flux in NSTX-U
    journal, June 2019


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


    Error field impact on mode locking and divertor heat flux in NSTX-U
    journal, June 2019