Impurity transport driven by fishbones in MAST

M. Cecconello; O.M. Jones; L. Garzotti; K.G. McClements; M. Carr; S.S. Henderson; S.E. Sharapov; I. Klimek

doi:10.1088/0029-5515/55/3/032002

Impurity transport driven by fishbones in MAST

M. Cecconello, O.M. Jones, L. Garzotti, K.G. McClements, M. Carr, S.S. Henderson, S.E. Sharapov, I. Klimek

Physics

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

4 Citations (Scopus)

Abstract

In MAST, bursting toroidal Alfvén eigenmodes and fishbones are observed to give rise to an asymmetric perturbation to the soft x-ray (SXR) emission close to the magnetic axis which grows and decays on the time scale of the fishbone evolution. As the fishbone nears its maximum amplitude, the SXR emission starts to increase (decrease) at radial positions smaller (larger) than the radial position of the magnetic axis. This trend in the SXR emission persists for a few milliseconds, until the fishbone starts to decay in amplitude and the slower overall trend of the SXR emission once again becomes dominant. A preliminary analysis suggests that the change in the SXR emission is due to the localized accumulation of high-Z impurities, sustained against parallel transport by the effects of fishbones on the fast ion population.

Original language	English
Article number	032002
Number of pages	8
Journal	Nuclear Fusion
Volume	55
Issue number	3
DOIs	https://doi.org/10.1088/0029-5515/55/3/032002
Publication status	Published - 6 Feb 2015

Keywords

spherical tokamaks
plasma impurities
soft X-ray

Access to Document

10.1088/0029-5515/55/3/032002

Cite this

@article{e3c43d873d1f4034b1c9f8eb3d80d0e6,

title = "Impurity transport driven by fishbones in MAST",

abstract = "In MAST, bursting toroidal Alfv{\'e}n eigenmodes and fishbones are observed to give rise to an asymmetric perturbation to the soft x-ray (SXR) emission close to the magnetic axis which grows and decays on the time scale of the fishbone evolution. As the fishbone nears its maximum amplitude, the SXR emission starts to increase (decrease) at radial positions smaller (larger) than the radial position of the magnetic axis. This trend in the SXR emission persists for a few milliseconds, until the fishbone starts to decay in amplitude and the slower overall trend of the SXR emission once again becomes dominant. A preliminary analysis suggests that the change in the SXR emission is due to the localized accumulation of high-Z impurities, sustained against parallel transport by the effects of fishbones on the fast ion population.",

keywords = "spherical tokamaks, plasma impurities, soft X-ray",

author = "M. Cecconello and O.M. Jones and L. Garzotti and K.G. McClements and M. Carr and S.S. Henderson and S.E. Sharapov and I. Klimek",

year = "2015",

month = feb,

day = "6",

doi = "10.1088/0029-5515/55/3/032002",

language = "English",

volume = "55",

journal = "Nuclear Fusion",

issn = "0029-5515",

number = "3",

}

TY - JOUR

T1 - Impurity transport driven by fishbones in MAST

AU - Cecconello, M.

AU - Jones, O.M.

AU - Garzotti, L.

AU - McClements, K.G.

AU - Carr, M.

AU - Henderson, S.S.

AU - Sharapov, S.E.

AU - Klimek, I.

PY - 2015/2/6

Y1 - 2015/2/6

N2 - In MAST, bursting toroidal Alfvén eigenmodes and fishbones are observed to give rise to an asymmetric perturbation to the soft x-ray (SXR) emission close to the magnetic axis which grows and decays on the time scale of the fishbone evolution. As the fishbone nears its maximum amplitude, the SXR emission starts to increase (decrease) at radial positions smaller (larger) than the radial position of the magnetic axis. This trend in the SXR emission persists for a few milliseconds, until the fishbone starts to decay in amplitude and the slower overall trend of the SXR emission once again becomes dominant. A preliminary analysis suggests that the change in the SXR emission is due to the localized accumulation of high-Z impurities, sustained against parallel transport by the effects of fishbones on the fast ion population.

AB - In MAST, bursting toroidal Alfvén eigenmodes and fishbones are observed to give rise to an asymmetric perturbation to the soft x-ray (SXR) emission close to the magnetic axis which grows and decays on the time scale of the fishbone evolution. As the fishbone nears its maximum amplitude, the SXR emission starts to increase (decrease) at radial positions smaller (larger) than the radial position of the magnetic axis. This trend in the SXR emission persists for a few milliseconds, until the fishbone starts to decay in amplitude and the slower overall trend of the SXR emission once again becomes dominant. A preliminary analysis suggests that the change in the SXR emission is due to the localized accumulation of high-Z impurities, sustained against parallel transport by the effects of fishbones on the fast ion population.

KW - spherical tokamaks

KW - plasma impurities

KW - soft X-ray

U2 - 10.1088/0029-5515/55/3/032002

DO - 10.1088/0029-5515/55/3/032002

M3 - Article

SN - 0029-5515

VL - 55

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 3

M1 - 032002

ER -

Impurity transport driven by fishbones in MAST

Abstract

Keywords

Access to Document

Fingerprint

Cite this