Alpha-particle velocity-space diagnostic in ITER

M. Salewski; M. Nocente; B. Madsen; Ivana Abramovic; M. Fitzgerald; G. Gorini; P. C. Hansen; W. W. Heidbrink; A. S. Jacobsen; T. Jensen; V. G. Kiptily; E. B. Klinkby; S. B. Korsholm; T. Kurki-Suonio; A. W. Larsen; F. Leipold; D. Moseev; S. K. Nielsen; S. D. Pinches; J. Rasmussen; M. Rebai; Mireille Schneider; A. Shevelev; S. Sipila; M. Stejner; M. Tardocchi

doi:10.1088/1741-4326/aace05

Alpha-particle velocity-space diagnostic in ITER

M. Salewski^*
, M. Nocente
, B. Madsen
, Ivana Abramovic
, M. Fitzgerald
, G. Gorini
, P. C. Hansen
, W. W. Heidbrink
, A. S. Jacobsen
, T. Jensen
, V. G. Kiptily
, E. B. Klinkby
, S. B. Korsholm
, T. Kurki-Suonio
, A. W. Larsen
, F. Leipold
, D. Moseev
, S. K. Nielsen
, S. D. Pinches
, J. Rasmussen

M. Rebai, Mireille Schneider, A. Shevelev, S. Sipila, M. Stejner, M. Tardocchi

^*Corresponding author for this work

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

64 Citations (Scopus)

Abstract

We discuss alpha-particle velocity-space diagnostic in ITER based oil the planned collective Thomson scattering (CTS) and gamma-ray spectrometry (GRS) systems as well as ASCOT simulations of the alpha-particle distribution function. GRS is sensitive to alpha-particles with energies E greater than or similar to 1.7 MeV at all pitches p, and CTS for E greater than or similar to 0.3 MeV and |p| less than or similar to 0.9. The remaining velocity space is not observed. GRS and CTS view the plasma (almost) perpendicularly to the magnetic field. Hence we cannot determine the sign of the pitch of the alpha-particles and cannot distinguish co- and counter-going alpha-particles with the currently planned alpha-particle diagnostics. Therefore we can only infer the sign-insensitive 2D distribution function f{E,|p|) by velocity-space tomography for E greater than or similar to 1.7 MeV. This is a serious limitation, since co- and counter-going alpha-particle populations are expected to have different birth rates and neoclassical transport as well as different anomalous transport due to interaction with modes such as Alfven eigenmodes. We propose the installation of an oblique GRS system on ITER to allow us to diagnostically track such anisotropy effects and to infer the full, sign-sensitive f(E,p) for E greater than or similar to 1.7 MeV. alpha-particles with E less than or similar to 1.7 MeV are diagnosed by CTS only, which does not allow velocity-space tomography on its own. Nevertheless, we show that measurements of the alpha-particle energy spectrum, which is an ITER measurement requirement, are now feasible for E greater than or similar to 0.3 MeV using a velocity-space tomography formalism assuming isotropy in velocity space.

Original language	English
Article number	096019
Number of pages	16
Journal	Nuclear Fusion
Volume	58
Issue number	9
DOIs	https://doi.org/10.1088/1741-4326/aace05
Publication status	Published - Sept 2018
MoE publication type	A1 Journal article-refereed

Funding

We thank the ITPA Energetic Particle Physics Topical Group for its support. The work leading to this publication has been funded partially by Fusion for Energy under Specific Grant Agreement F4E-393-SG04. This publication reflects the views only of the authors, and Fusion for Energy cannot be held responsible for any use which may be made of the information contained therein. This work has been partially carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization, nor the European Commission.

UN SDGs

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

SDG 7 Affordable and Clean Energy

Keywords

ITER
gamma-ray spectrometry
collective Thomson scattering
velocity-space tomography
alpha-particle diagnostic
GAMMA-RAY DIAGNOSTICS
ENERGETIC IONS
KINETIC-EQUATION
FUSION PLASMAS
CHAPTER 5
JET
PHYSICS
SPECTROSCOPY
SCINTILLATORS
HE-4

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10.1088/1741-4326/aace05

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Salewski, M., Nocente, M., Madsen, B., Abramovic, I., Fitzgerald, M., Gorini, G., Hansen, P. C., Heidbrink, W. W., Jacobsen, A. S., Jensen, T., Kiptily, V. G., Klinkby, E. B., Korsholm, S. B., Kurki-Suonio, T., Larsen, A. W., Leipold, F., Moseev, D., Nielsen, S. K., Pinches, S. D., ... Tardocchi, M. (2018). Alpha-particle velocity-space diagnostic in ITER. Nuclear Fusion, 58(9), Article 096019. https://doi.org/10.1088/1741-4326/aace05

@article{5d8228c852cd4afda8fb555dff7c48e2,

title = "Alpha-particle velocity-space diagnostic in ITER",

abstract = "We discuss alpha-particle velocity-space diagnostic in ITER based oil the planned collective Thomson scattering (CTS) and gamma-ray spectrometry (GRS) systems as well as ASCOT simulations of the alpha-particle distribution function. GRS is sensitive to alpha-particles with energies E greater than or similar to 1.7 MeV at all pitches p, and CTS for E greater than or similar to 0.3 MeV and |p| less than or similar to 0.9. The remaining velocity space is not observed. GRS and CTS view the plasma (almost) perpendicularly to the magnetic field. Hence we cannot determine the sign of the pitch of the alpha-particles and cannot distinguish co- and counter-going alpha-particles with the currently planned alpha-particle diagnostics. Therefore we can only infer the sign-insensitive 2D distribution function f\{E,|p|) by velocity-space tomography for E greater than or similar to 1.7 MeV. This is a serious limitation, since co- and counter-going alpha-particle populations are expected to have different birth rates and neoclassical transport as well as different anomalous transport due to interaction with modes such as Alfven eigenmodes. We propose the installation of an oblique GRS system on ITER to allow us to diagnostically track such anisotropy effects and to infer the full, sign-sensitive f(E,p) for E greater than or similar to 1.7 MeV. alpha-particles with E less than or similar to 1.7 MeV are diagnosed by CTS only, which does not allow velocity-space tomography on its own. Nevertheless, we show that measurements of the alpha-particle energy spectrum, which is an ITER measurement requirement, are now feasible for E greater than or similar to 0.3 MeV using a velocity-space tomography formalism assuming isotropy in velocity space.",

keywords = "ITER, gamma-ray spectrometry, collective Thomson scattering, velocity-space tomography, alpha-particle diagnostic, GAMMA-RAY DIAGNOSTICS, ENERGETIC IONS, KINETIC-EQUATION, FUSION PLASMAS, CHAPTER 5, JET, PHYSICS, SPECTROSCOPY, SCINTILLATORS, HE-4",

author = "M. Salewski and M. Nocente and B. Madsen and Ivana Abramovic and M. Fitzgerald and G. Gorini and Hansen, \{P. C.\} and Heidbrink, \{W. W.\} and Jacobsen, \{A. S.\} and T. Jensen and Kiptily, \{V. G.\} and Klinkby, \{E. B.\} and Korsholm, \{S. B.\} and T. Kurki-Suonio and Larsen, \{A. W.\} and F. Leipold and D. Moseev and Nielsen, \{S. K.\} and Pinches, \{S. D.\} and J. Rasmussen and M. Rebai and Mireille Schneider and A. Shevelev and S. Sipila and M. Stejner and M. Tardocchi",

year = "2018",

month = sep,

doi = "10.1088/1741-4326/aace05",

language = "English",

volume = "58",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "Institute of Physics Publishing",

number = "9",

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Salewski, M, Nocente, M, Madsen, B, Abramovic, I, Fitzgerald, M, Gorini, G, Hansen, PC, Heidbrink, WW, Jacobsen, AS, Jensen, T, Kiptily, VG, Klinkby, EB, Korsholm, SB, Kurki-Suonio, T, Larsen, AW, Leipold, F, Moseev, D, Nielsen, SK, Pinches, SD, Rasmussen, J, Rebai, M, Schneider, M, Shevelev, A, Sipila, S, Stejner, M & Tardocchi, M 2018, 'Alpha-particle velocity-space diagnostic in ITER', Nuclear Fusion, vol. 58, no. 9, 096019. https://doi.org/10.1088/1741-4326/aace05

TY - JOUR

T1 - Alpha-particle velocity-space diagnostic in ITER

AU - Salewski, M.

AU - Nocente, M.

AU - Madsen, B.

AU - Abramovic, Ivana

AU - Fitzgerald, M.

AU - Gorini, G.

AU - Hansen, P. C.

AU - Heidbrink, W. W.

AU - Jacobsen, A. S.

AU - Jensen, T.

AU - Kiptily, V. G.

AU - Klinkby, E. B.

AU - Korsholm, S. B.

AU - Kurki-Suonio, T.

AU - Larsen, A. W.

AU - Leipold, F.

AU - Moseev, D.

AU - Nielsen, S. K.

AU - Pinches, S. D.

AU - Rasmussen, J.

AU - Rebai, M.

AU - Schneider, Mireille

AU - Shevelev, A.

AU - Sipila, S.

AU - Stejner, M.

AU - Tardocchi, M.

PY - 2018/9

Y1 - 2018/9

N2 - We discuss alpha-particle velocity-space diagnostic in ITER based oil the planned collective Thomson scattering (CTS) and gamma-ray spectrometry (GRS) systems as well as ASCOT simulations of the alpha-particle distribution function. GRS is sensitive to alpha-particles with energies E greater than or similar to 1.7 MeV at all pitches p, and CTS for E greater than or similar to 0.3 MeV and |p| less than or similar to 0.9. The remaining velocity space is not observed. GRS and CTS view the plasma (almost) perpendicularly to the magnetic field. Hence we cannot determine the sign of the pitch of the alpha-particles and cannot distinguish co- and counter-going alpha-particles with the currently planned alpha-particle diagnostics. Therefore we can only infer the sign-insensitive 2D distribution function f{E,|p|) by velocity-space tomography for E greater than or similar to 1.7 MeV. This is a serious limitation, since co- and counter-going alpha-particle populations are expected to have different birth rates and neoclassical transport as well as different anomalous transport due to interaction with modes such as Alfven eigenmodes. We propose the installation of an oblique GRS system on ITER to allow us to diagnostically track such anisotropy effects and to infer the full, sign-sensitive f(E,p) for E greater than or similar to 1.7 MeV. alpha-particles with E less than or similar to 1.7 MeV are diagnosed by CTS only, which does not allow velocity-space tomography on its own. Nevertheless, we show that measurements of the alpha-particle energy spectrum, which is an ITER measurement requirement, are now feasible for E greater than or similar to 0.3 MeV using a velocity-space tomography formalism assuming isotropy in velocity space.

AB - We discuss alpha-particle velocity-space diagnostic in ITER based oil the planned collective Thomson scattering (CTS) and gamma-ray spectrometry (GRS) systems as well as ASCOT simulations of the alpha-particle distribution function. GRS is sensitive to alpha-particles with energies E greater than or similar to 1.7 MeV at all pitches p, and CTS for E greater than or similar to 0.3 MeV and |p| less than or similar to 0.9. The remaining velocity space is not observed. GRS and CTS view the plasma (almost) perpendicularly to the magnetic field. Hence we cannot determine the sign of the pitch of the alpha-particles and cannot distinguish co- and counter-going alpha-particles with the currently planned alpha-particle diagnostics. Therefore we can only infer the sign-insensitive 2D distribution function f{E,|p|) by velocity-space tomography for E greater than or similar to 1.7 MeV. This is a serious limitation, since co- and counter-going alpha-particle populations are expected to have different birth rates and neoclassical transport as well as different anomalous transport due to interaction with modes such as Alfven eigenmodes. We propose the installation of an oblique GRS system on ITER to allow us to diagnostically track such anisotropy effects and to infer the full, sign-sensitive f(E,p) for E greater than or similar to 1.7 MeV. alpha-particles with E less than or similar to 1.7 MeV are diagnosed by CTS only, which does not allow velocity-space tomography on its own. Nevertheless, we show that measurements of the alpha-particle energy spectrum, which is an ITER measurement requirement, are now feasible for E greater than or similar to 0.3 MeV using a velocity-space tomography formalism assuming isotropy in velocity space.

KW - ITER

KW - gamma-ray spectrometry

KW - collective Thomson scattering

KW - velocity-space tomography

KW - alpha-particle diagnostic

KW - GAMMA-RAY DIAGNOSTICS

KW - ENERGETIC IONS

KW - KINETIC-EQUATION

KW - FUSION PLASMAS

KW - CHAPTER 5

KW - JET

KW - PHYSICS

KW - SPECTROSCOPY

KW - SCINTILLATORS

KW - HE-4

U2 - 10.1088/1741-4326/aace05

DO - 10.1088/1741-4326/aace05

M3 - Article

SN - 0029-5515

VL - 58

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 9

M1 - 096019

ER -

Alpha-particle velocity-space diagnostic in ITER

Abstract

Funding

UN SDGs

Keywords

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