On the very high energy confinement observed in super H-mode DIII-D experiments

Ding, S.; Garofalo, A. M.; Knolker, M.; Marinoni, A.; McClenaghan, J.; Grierson, B. A.

doi:10.1088/1741-4326/ab66db

Title: On the very high energy confinement observed in super H-mode DIII-D experiments

Abstract

Analysis of recent super H-mode experiments on DIII-D shows that high rotation, not high pedestal, plays the essential role in achieving very high confinement H_98y2>1.5. Very high confinement is reached early on in the H-mode phase of these discharges, when the pedestal is still very low, but after the toroidal rotation has already built-up to very high levels in the core. As the discharge evolves, the rotation drops, and so does the energy confinement, despite a sustained very high-pressure pedestal. During this evolution, the confinement quality is linearly correlated with the core toroidal rotation, which varies according to different levels of injected neutral beam torque per particle. Core transport modeling shows that the contribution from rotation in the E×B shear is responsible for confinement quality significantly in excess of standard H-mode (H_98y2~1).

Authors:

^[1];

^[2];

^[3]; Marinoni, A. ^[4]; McClenaghan, J. ^[2];

^[5]

Oak Ridge Associated Univ., Oak Ridge, TN (United States); Chinese Academy of Sciences (CAS), Beijing (China)
General Atomics, San Diego, CA (United States)
Oak Ridge Associated Univ., Oak Ridge, TN (United States)
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Publication Date:: Wed Jan 22 00:00:00 EST 2020

Research Org.:: General Atomics, San Diego, CA (United States)

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

OSTI Identifier:: 1594863

Grant/Contract Number:: FC02-04ER54698

Resource Type:: Accepted Manuscript

Journal Name:: Nuclear Fusion

Additional Journal Information:: Journal Volume: 60; 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; super H-mode; high thermal energy confinement; toroidal rotation; E×B shear

Citation Formats


                    Ding, S., Garofalo, A. M., Knolker, M., Marinoni, A., McClenaghan, J., and Grierson, B. A. On the very high energy confinement observed in super H-mode DIII-D experiments.  United States: N. p., 2020. 
Web.  doi:10.1088/1741-4326/ab66db.

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                    Ding, S., Garofalo, A. M., Knolker, M., Marinoni, A., McClenaghan, J., & Grierson, B. A. On the very high energy confinement observed in super H-mode DIII-D experiments.  United States.  https://doi.org/10.1088/1741-4326/ab66db

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                    Ding, S., Garofalo, A. M., Knolker, M., Marinoni, A., McClenaghan, J., and Grierson, B. A. Wed .  
"On the very high energy confinement observed in super H-mode DIII-D experiments".  United States.  https://doi.org/10.1088/1741-4326/ab66db.  https://www.osti.gov/servlets/purl/1594863.

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@article{osti_1594863,

  title        = {On the very high energy confinement observed in super H-mode DIII-D experiments},

  author       = {Ding, S. and Garofalo, A. M. and Knolker, M. and Marinoni, A. and McClenaghan, J. and Grierson, B. A.},

  abstractNote = {Analysis of recent super H-mode experiments on DIII-D shows that high rotation, not high pedestal, plays the essential role in achieving very high confinement H98y2>1.5. Very high confinement is reached early on in the H-mode phase of these discharges, when the pedestal is still very low, but after the toroidal rotation has already built-up to very high levels in the core. As the discharge evolves, the rotation drops, and so does the energy confinement, despite a sustained very high-pressure pedestal. During this evolution, the confinement quality is linearly correlated with the core toroidal rotation, which varies according to different levels of injected neutral beam torque per particle. Core transport modeling shows that the contribution from rotation in the E×B shear is responsible for confinement quality significantly in excess of standard H-mode (H98y2~1).},

  doi          = {10.1088/1741-4326/ab66db},

  journal      = {Nuclear Fusion},

  number       = 3,

  volume       = 60,

  place        = {United States},

  year         = {Wed Jan 22 00:00:00 EST 2020},

  month        = {Wed Jan 22 00:00:00 EST 2020}

}

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Title: On the very high energy confinement observed in super H-mode DIII-D experiments

Abstract

Citation Formats

Properties of ion temperature gradient drift instabilities in H ‐mode plasmas journal, June 1989

Integrated modeling applications for tokamak experiments with OMFIT journal, July 2015

Access to high beta advanced inductive plasmas at low injected torque journal, September 2013

Nonlinear Stabilization of Tokamak Microturbulence by Fast Ions journal, October 2013

ITER predictions using the GYRO verified and experimentally validated trapped gyro-Landau fluid transport model journal, June 2011

Tokamak profile prediction using direct gyrokinetic and neoclassical simulation journal, June 2009

The role of zonal flows in the saturation of multi-scale gyrokinetic turbulence journal, June 2016

A first-principles predictive model of the pedestal height and width: development, testing and ITER optimization with the EPED model journal, August 2011

Mode locking in tokamaks journal, December 1990

Ion temperature‐gradient‐driven modes and anomalous ion transport in tokamaks journal, May 1989

Access to a New Plasma Edge State with High Density and Pressures using the Quiescent H Mode journal, September 2014

Quantitative predictions of tokamak energy confinement from first‐principles simulations with kinetic effects journal, June 1995

Global energy confinement degradation due to macroscopic phenomena in tokamaks journal, February 1990

Critical gradient formula for toroidal electron temperature gradient modes journal, September 2001

Dependence of intrinsic torque and momentum confinement on normalized gyroradius and collisionality in the DIII-D tokamak journal, April 2017

Role of T e / T i and ∇ v tor in ion heat transport of ASDEX Upgrade H-mode plasmas journal, November 2006

Transitionless enhanced confinement and the role of radial electric field shear journal, February 2000

A theory-based transport model with comprehensive physics journal, May 2007

Influence of toroidal rotation on transport and stability in hybrid scenario plasmas in DIII-D journal, May 2008

Full linearized Fokker–Planck collisions in neoclassical transport simulations journal, December 2011

Chapter 2: Plasma confinement and transport journal, June 2007

Properties of ion temperature gradient drift instabilities in H ‐mode plasmas
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Nonlinear Stabilization of Tokamak Microturbulence by Fast Ions
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Tokamak profile prediction using direct gyrokinetic and neoclassical simulation
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The role of zonal flows in the saturation of multi-scale gyrokinetic turbulence
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A first-principles predictive model of the pedestal height and width: development, testing and ITER optimization with the EPED model
journal, August 2011

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journal, December 1990

Ion temperature‐gradient‐driven modes and anomalous ion transport in tokamaks
journal, May 1989

Access to a New Plasma Edge State with High Density and Pressures using the Quiescent $H$ Mode
journal, September 2014

Quantitative predictions of tokamak energy confinement from first‐principles simulations with kinetic effects
journal, June 1995

Global energy confinement degradation due to macroscopic phenomena in tokamaks
journal, February 1990

Critical gradient formula for toroidal electron temperature gradient modes
journal, September 2001

Dependence of intrinsic torque and momentum confinement on normalized gyroradius and collisionality in the DIII-D tokamak
journal, April 2017

Role of T _e / T _i and ∇ v _tor in ion heat transport of ASDEX Upgrade H-mode plasmas
journal, November 2006

Transitionless enhanced confinement and the role of radial electric field shear
journal, February 2000

A theory-based transport model with comprehensive physics
journal, May 2007

Influence of toroidal rotation on transport and stability in hybrid scenario plasmas in DIII-D
journal, May 2008

Full linearized Fokker–Planck collisions in neoclassical transport simulations
journal, December 2011

Chapter 2: Plasma confinement and transport
journal, June 2007