Visualization of Fast Ion Phase-Space Flow Driven by Alfvén Instabilities

X. D. Du; M. A. Van Zeeland; W. W. Heidbrink; J. Gonzalez-Martin; K. Särkimäki; A. Snicker; D. Lin; C. S. Collins; M. E. Austin; G. R. McKee; Z. Yan; Y. Todo; W. Wu

doi:10.1103/PhysRevLett.127.235002

Visualization of Fast Ion Phase-Space Flow Driven by Alfvén Instabilities

X. D. Du^*
, M. A. Van Zeeland
, W. W. Heidbrink
, J. Gonzalez-Martin
, K. Särkimäki
, A. Snicker
, D. Lin
, C. S. Collins
, M. E. Austin
, G. R. McKee
, Z. Yan
, Y. Todo
, W. Wu

^*Corresponding author for this work

Department of Applied Physics

Research output: Contribution to journal › Article › Scientific › peer-review

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Abstract

Fast ion phase-space flow, driven by Alfvén eigenmodes (AEs), is measured by an imaging neutral particle analyzer in the DIII-D tokamak. The flow firstly appears near the minimum safety factor at the injection energy of neutral beams, and then moves radially inward and outward by gaining and losing energy, respectively. The flow trajectories in phase space align well with the intersection lines of the constant magnetic moment surfaces and constant E-(ω/n)Pζ surfaces, where E, Pζ are the energy and canonical toroidal momentum of ions; ω and n are angular frequencies and toroidal mode numbers of AEs. It is found that the flow is so destructive that the thermalization of fast ions is no longer observed in regions of strong interaction. The measured phase-space flow is consistent with nonlinear hybrid kinetic-magnetohydrodynamics simulation. Calculations of the relatively narrow phase-space islands reveal that fast ions must transition between different flow trajectories to experience large-scale phase-space transport.

Original language	English
Article number	235002
Pages (from-to)	1-5
Number of pages	5
Journal	Physical Review Letters
Volume	127
Issue number	23
DOIs	https://doi.org/10.1103/PhysRevLett.127.235002
Publication status	Published - 3 Dec 2021
MoE publication type	A1 Journal article-refereed

Funding

The author (X. D. Du) would like to thank M. Podestà, G. J. Kramer, and R.Nazikian for fruitful discussions. This work was supported by the US DOE under DE-AC05-00OR22725, DE-FC02-04ER54698, DE-AC02-09CH11466, and DE-SC0015878. The ASCOT5 project has received funding from the European Research Council under Grant Agreement No. 647121. This ASCOT5 project has been carried out within the framework of the EUROfusion consortium and has received funding from the Euratom research and training programme under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The ASCOT5 project was also partially funded by the Academy of Finland projects No. 324759 and No. 298126. We acknowledge the computational resources provided by Aalto Science-IT project. The MEGA simulation used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under Contract No. DE-AC02-05CH11231.

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This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

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10.1103/PhysRevLett.127.235002

Visualization of Fast Ion Phase-Space Flow Driven by Alfvén InstabilitiesFinal published version, 2.78 MB

Cite this

@article{26346c3048a54d2fb422708a45b3b410,

title = "Visualization of Fast Ion Phase-Space Flow Driven by Alfv{\'e}n Instabilities",

abstract = "Fast ion phase-space flow, driven by Alfv{\'e}n eigenmodes (AEs), is measured by an imaging neutral particle analyzer in the DIII-D tokamak. The flow firstly appears near the minimum safety factor at the injection energy of neutral beams, and then moves radially inward and outward by gaining and losing energy, respectively. The flow trajectories in phase space align well with the intersection lines of the constant magnetic moment surfaces and constant E-(ω/n)Pζ surfaces, where E, Pζ are the energy and canonical toroidal momentum of ions; ω and n are angular frequencies and toroidal mode numbers of AEs. It is found that the flow is so destructive that the thermalization of fast ions is no longer observed in regions of strong interaction. The measured phase-space flow is consistent with nonlinear hybrid kinetic-magnetohydrodynamics simulation. Calculations of the relatively narrow phase-space islands reveal that fast ions must transition between different flow trajectories to experience large-scale phase-space transport. ",

author = "Du, \{X. D.\} and \{Van Zeeland\}, \{M. A.\} and Heidbrink, \{W. W.\} and J. Gonzalez-Martin and K. S{\"a}rkim{\"a}ki and A. Snicker and D. Lin and Collins, \{C. S.\} and Austin, \{M. E.\} and McKee, \{G. R.\} and Z. Yan and Y. Todo and W. Wu",

note = "| openaire: EC/H2020/633053/EU//EUROfusion Funding Information: The author (X. D. Du) would like to thank M. Podest{\`a}, G. J. Kramer, and R.Nazikian for fruitful discussions. This work was supported by the US DOE under DE-AC05-00OR22725, DE-FC02-04ER54698, DE-AC02-09CH11466, and DE-SC0015878. The ASCOT5 project has received funding from the European Research Council under Grant Agreement No. 647121. This ASCOT5 project has been carried out within the framework of the EUROfusion consortium and has received funding from the Euratom research and training programme under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The ASCOT5 project was also partially funded by the Academy of Finland projects No. 324759 and No. 298126. We acknowledge the computational resources provided by Aalto Science-IT project. The MEGA simulation used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under Contract No. DE-AC02-05CH11231. Publisher Copyright: {\textcopyright} 2021 American Physical Society. ",

year = "2021",

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doi = "10.1103/PhysRevLett.127.235002",

language = "English",

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AU - Du, X. D.

AU - Van Zeeland, M. A.

AU - Heidbrink, W. W.

AU - Gonzalez-Martin, J.

AU - Särkimäki, K.

AU - Snicker, A.

AU - Lin, D.

AU - Collins, C. S.

AU - Austin, M. E.

AU - McKee, G. R.

AU - Yan, Z.

AU - Todo, Y.

AU - Wu, W.

N1 - | openaire: EC/H2020/633053/EU//EUROfusion Funding Information: The author (X. D. Du) would like to thank M. Podestà, G. J. Kramer, and R.Nazikian for fruitful discussions. This work was supported by the US DOE under DE-AC05-00OR22725, DE-FC02-04ER54698, DE-AC02-09CH11466, and DE-SC0015878. The ASCOT5 project has received funding from the European Research Council under Grant Agreement No. 647121. This ASCOT5 project has been carried out within the framework of the EUROfusion consortium and has received funding from the Euratom research and training programme under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The ASCOT5 project was also partially funded by the Academy of Finland projects No. 324759 and No. 298126. We acknowledge the computational resources provided by Aalto Science-IT project. The MEGA simulation used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under Contract No. DE-AC02-05CH11231. Publisher Copyright: © 2021 American Physical Society.

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N2 - Fast ion phase-space flow, driven by Alfvén eigenmodes (AEs), is measured by an imaging neutral particle analyzer in the DIII-D tokamak. The flow firstly appears near the minimum safety factor at the injection energy of neutral beams, and then moves radially inward and outward by gaining and losing energy, respectively. The flow trajectories in phase space align well with the intersection lines of the constant magnetic moment surfaces and constant E-(ω/n)Pζ surfaces, where E, Pζ are the energy and canonical toroidal momentum of ions; ω and n are angular frequencies and toroidal mode numbers of AEs. It is found that the flow is so destructive that the thermalization of fast ions is no longer observed in regions of strong interaction. The measured phase-space flow is consistent with nonlinear hybrid kinetic-magnetohydrodynamics simulation. Calculations of the relatively narrow phase-space islands reveal that fast ions must transition between different flow trajectories to experience large-scale phase-space transport.

AB - Fast ion phase-space flow, driven by Alfvén eigenmodes (AEs), is measured by an imaging neutral particle analyzer in the DIII-D tokamak. The flow firstly appears near the minimum safety factor at the injection energy of neutral beams, and then moves radially inward and outward by gaining and losing energy, respectively. The flow trajectories in phase space align well with the intersection lines of the constant magnetic moment surfaces and constant E-(ω/n)Pζ surfaces, where E, Pζ are the energy and canonical toroidal momentum of ions; ω and n are angular frequencies and toroidal mode numbers of AEs. It is found that the flow is so destructive that the thermalization of fast ions is no longer observed in regions of strong interaction. The measured phase-space flow is consistent with nonlinear hybrid kinetic-magnetohydrodynamics simulation. Calculations of the relatively narrow phase-space islands reveal that fast ions must transition between different flow trajectories to experience large-scale phase-space transport.

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Visualization of Fast Ion Phase-Space Flow Driven by Alfvén Instabilities

Abstract

Funding

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Snicker Antti AT-palkka: Fast and furious of fusion plasmas

also: Fusion with a twist: Racing particles (also) in W7-X stellarator

Science-IT

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Visualization of Fast Ion Phase-Space Flow Driven by Alfvén Instabilities

Abstract

Funding

UN SDGs

Access to Document

Other files and links

Fingerprint

Projects

Snicker Antti AT-palkka: Fast and furious of fusion plasmas

also: Fusion with a twist: Racing particles (also) in W7-X stellarator

Equipment

Science-IT

Cite this