Download ppt - Passive and Active Stability of Kink/RWM and Rotation Control in KSTAR-relevant Equilibria

NSTXNSTX NSTX Research Forum 2010 - Y.S. Park December 1, 2009

Passive and Active Stability of Kink/RWM and Rotation Passive and Active Stability of Kink/RWM and Rotation Control in KSTAR-relevant EquilibriaControl in KSTAR-relevant Equilibria

Y.S. Park,

S.A. Sabbagh, J.M. Bialek,

J.W. Berkery, O. Katsuro-Hopkins

Department of Applied Physics, Columbia University,

New York, NY, USA

NSTX Research Forum

December 1st, 2009Princeton Plasma Physics Laboratory

Culham Sci CtrU St. Andrews

York UChubu UFukui U

Hiroshima UHyogo UKyoto U

Kyushu UKyushu Tokai U

NIFSNiigata UU Tokyo

JAEAHebrew UIoffe Inst

RRC Kurchatov InstTRINITI

NFRIKAIST

POSTECHASIPP

ENEA, FrascatiCEA, Cadarache

IPP, JülichIPP, Garching

ASCR, Czech RepU Quebec

NSTXNSTX Supported by

College W&MColorado Sch MinesColumbia UComp-XGeneral AtomicsINELJohns Hopkins ULANLLLNLLodestarMITNova PhotonicsNew York UOld Dominion UORNLPPPLPSIPrinceton UPurdue USNLThink Tank, Inc.UC DavisUC IrvineUCLAUCSDU ColoradoU MarylandU RochesterU WashingtonU Wisconsin

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NSTXNSTX NSTX Research Forum 2010 - Y.S. Park December 1, 2009 2

XP Supports NSTX-KSTAR Joint Experiment

• Motivation Verify suitability of the planned IVCC/passive plate design for RWM stabilization in

KSTAR Demonstrate rotation control by n=2 magnetic braking to determine an optimal rotation

control strategy of KSTAR, i.e. counter-NBI vs. magnetic braking by IVCC Possible large aspect ratio (AR) experiment under high N of NSTX

• GoalsPrerequisite : Generate KSTAR-relevant lower q95 and , higher AR equilibria

Stability threshold of Kink/RWM with various N, li, wall-plasma gap distance

Active stabilization of RWM Rotation control by n=2 magnetic braking

• Contribution Comparison of this XP to lower aspect ratio NSTX plasmas (possible q95 & AR effects)

Based on the NSTX-KSTAR joint experiment, support upcoming KSTAR high beta experiment by using KSTAR-relevant target equilibria

Possible support to several ITPA (MDC-2, MDC-12, MDC-4, MDC-14)


KSTAR High Beta Experiment is Upcoming

• Major KSTAR upgrade in the year 2010 for high beta experiment IVCC, passive plates (4 toroidal segmented IVCC n=2 field), divertor plates First NBI & LHCD (Paux will be 3MW in 2010 and upgraded to 9.5MW until 2012)

PF power supply upgrade for double null & long pulse discharge

-KSTAR achieved its goal of 2009 experimental campaign

(2009 campaign during Oct.~ Nov. 2009 - 7 weeks)

- 320kA, 3.6 sec discharge obtained (shot# 2048 on Nov. 18 th 2009)

-KSTAR IVCC to control plasma position &

RWM/FEC/ELM (upper/middle/lower)

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Approach and Run Plan

• Approach Vacuum field analysis to compare the applied field spectrum of the two devices Generate KSTAR-relevant target equilibria having following parameters (XP818)

(N = 2.5~5.0 or higher, li = 0.6~1.0, = 2.0, q95 and AR closest to 4.0 and 3.6, respectively)

Passive Kink/RWM stability with N, li, gap distance change

Demonstrate n=2 magnetic braking with various input torque from NBI and applied coil current

• Run plan (1 day) Target plasma development n = 1 & 3 experiments : min. 8 shots

• Kink/RWM stability threshold• RWM active feedback stabilization• Locked mode threshold

n = 2 experiments : min. 4 shots• Rotation control by magnetic braking• ELM dynamics investigation• NTM threshold or interference

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