Stability of JET discharges with zero core current density

B.C. Stratton; J. Breslau; R. Budny; S. Jardin; N.C. Hawkes; T. Hender; G. Huysmans; Tuomas Tala; JET-EFDA contributors

Stability of JET discharges with zero core current density

B.C. Stratton, J. Breslau, R. Budny, S. Jardin, N.C. Hawkes, T. Hender, G. Huysmans, Tuomas Tala, JET-EFDA contributors

Research output: Contribution to conference › Conference article › Scientific › peer-review

Abstract

Injection of lower hybrid heating and current drive into the current ramp-up phase of JET discharges can produce extremely reversed q-profiles characterized by a core region (r/a less than 0.2) of zero current density (within Motional Stark Effect diagnostic measurement errors) and q greater than 1 everywhere [N. C. Hawkes, et al., Phys. Rev. Lett. (accepted July 2001)]. Electron temperature measurements show sawtooth-like collapses and the presence of an internal transport barrier. The core current density does not appear to go negative, although TSC/LSC code modeling indicates that the drive for this is present. A 2-D, two fluid simulation predicts that discharges with negative core current would be unstable to n=0, m=1 modes. The possibility that these modes redistribute the core current to prevent it from becoming negative is examined.

Original language	English
Number of pages	6
Publication status	Published - 2001
MoE publication type	Not Eligible
Event	43rd Annual Meeting of the APS Division of Plasma Physics - Long Beach, United States Duration: 29 Oct 2001 → 2 Nov 2001

Conference

Conference	43rd Annual Meeting of the APS Division of Plasma Physics
Country/Territory	United States
City	Long Beach
Period	29/10/01 → 2/11/01

Cite this

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title = "Stability of JET discharges with zero core current density",

abstract = "Injection of lower hybrid heating and current drive into the current ramp-up phase of JET discharges can produce extremely reversed q-profiles characterized by a core region (r/a less than 0.2) of zero current density (within Motional Stark Effect diagnostic measurement errors) and q greater than 1 everywhere [N. C. Hawkes, et al., Phys. Rev. Lett. (accepted July 2001)]. Electron temperature measurements show sawtooth-like collapses and the presence of an internal transport barrier. The core current density does not appear to go negative, although TSC/LSC code modeling indicates that the drive for this is present. A 2-D, two fluid simulation predicts that discharges with negative core current would be unstable to n=0, m=1 modes. The possibility that these modes redistribute the core current to prevent it from becoming negative is examined.",

author = "B.C. Stratton and J. Breslau and R. Budny and S. Jardin and N.C. Hawkes and T. Hender and G. Huysmans and Tuomas Tala and {JET-EFDA contributors}",

note = "based on poster GP1.044 Not published in the journal proceedings https://aip.scitation.org/toc/php/9/5?tocSection=REVIEW%2C+TUTORIAL%2C+AND+INVITED+PAPERS+FROM+THE+43RD+ANNUAL+MEETING+OF+THE+++++++++++++++++++++APS+DIVISION+OF+PLASMA+PHYSICS; 43rd Annual Meeting of the APS Division of Plasma Physics ; Conference date: 29-10-2001 Through 02-11-2001",

year = "2001",

language = "English",

}

TY - CONF

T1 - Stability of JET discharges with zero core current density

AU - Stratton, B.C.

AU - Breslau, J.

AU - Budny, R.

AU - Jardin, S.

AU - Hawkes, N.C.

AU - Hender, T.

AU - Huysmans, G.

AU - Tala, Tuomas

AU - JET-EFDA contributors

N1 - based on poster GP1.044 Not published in the journal proceedings https://aip.scitation.org/toc/php/9/5?tocSection=REVIEW%2C+TUTORIAL%2C+AND+INVITED+PAPERS+FROM+THE+43RD+ANNUAL+MEETING+OF+THE+++++++++++++++++++++APS+DIVISION+OF+PLASMA+PHYSICS

PY - 2001

Y1 - 2001

N2 - Injection of lower hybrid heating and current drive into the current ramp-up phase of JET discharges can produce extremely reversed q-profiles characterized by a core region (r/a less than 0.2) of zero current density (within Motional Stark Effect diagnostic measurement errors) and q greater than 1 everywhere [N. C. Hawkes, et al., Phys. Rev. Lett. (accepted July 2001)]. Electron temperature measurements show sawtooth-like collapses and the presence of an internal transport barrier. The core current density does not appear to go negative, although TSC/LSC code modeling indicates that the drive for this is present. A 2-D, two fluid simulation predicts that discharges with negative core current would be unstable to n=0, m=1 modes. The possibility that these modes redistribute the core current to prevent it from becoming negative is examined.

AB - Injection of lower hybrid heating and current drive into the current ramp-up phase of JET discharges can produce extremely reversed q-profiles characterized by a core region (r/a less than 0.2) of zero current density (within Motional Stark Effect diagnostic measurement errors) and q greater than 1 everywhere [N. C. Hawkes, et al., Phys. Rev. Lett. (accepted July 2001)]. Electron temperature measurements show sawtooth-like collapses and the presence of an internal transport barrier. The core current density does not appear to go negative, although TSC/LSC code modeling indicates that the drive for this is present. A 2-D, two fluid simulation predicts that discharges with negative core current would be unstable to n=0, m=1 modes. The possibility that these modes redistribute the core current to prevent it from becoming negative is examined.

M3 - Conference article

T2 - 43rd Annual Meeting of the APS Division of Plasma Physics

Y2 - 29 October 2001 through 2 November 2001

ER -

Stability of JET discharges with zero core current density

Abstract

Conference

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