Supported by
This presentation is the property of its rightful owner.
Sponsored Links
1 / 7

S. A. Sabbagh, T. Evans, D. Gates, R. Maingi, J.E. Menard, J.K. Park, many others… PowerPoint PPT Presentation


  • 51 Views
  • Uploaded on
  • Presentation posted in: General

Supported by. Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics NYU ORNL PPPL PSI SNL UC Davis UC Irvine UCLA UCSD U Maryland U New Mexico U Rochester U Washington U Wisconsin Culham Sci Ctr Hiroshima U HIST Kyushu Tokai U

Download Presentation

S. A. Sabbagh, T. Evans, D. Gates, R. Maingi, J.E. Menard, J.K. Park, many others…

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


S a sabbagh t evans d gates r maingi j e menard j k park many others

Supported by

Columbia U

Comp-X

General Atomics

INEL

Johns Hopkins U

LANL

LLNL

Lodestar

MIT

Nova Photonics

NYU

ORNL

PPPL

PSI

SNL

UC Davis

UC Irvine

UCLA

UCSD

U Maryland

U New Mexico

U Rochester

U Washington

U Wisconsin

Culham Sci Ctr

Hiroshima U

HIST

Kyushu Tokai U

Niigata U

Tsukuba U

U Tokyo

JAERI

Ioffe Inst

TRINITI

KBSI

KAIST

ENEA, Frascati

CEA, Cadarache

IPP, Jülich

IPP, Garching

U Quebec

Joint Experiment on ELM Mitigation with Midplane Control Coils

S. A. Sabbagh, T. Evans, D. Gates, R. Maingi, J.E. Menard, J.K. Park, many others…

Joint ELM Mitigation XP Meeting

February 4, 2008

Princeton Plasma Physics Laboratory

V1.0


Considerations for joint elm mitigation xp run plan

Considerations for Joint ELM Mitigation XP Run Plan

  • Target Plasmas and General Approaches

    • What target(s) should be used?

      • Giant ELMs, or smaller ELMs?

      • What variation of q95?

      • What plasma shape, DRSEP, etc. ?

    • DC applied fields

      • Decide on “most favorable” approaches (see strawman run plan)

    • AC applied fields

      • Still examining effect ELMs, connection to toroidal rotation (SAS)

    • n = 1 feedback – use Br feedback on ELMs with frequency < 1kHz

  • Technical Logistics of the Run Plan

    • Application of non-standard DC fields will require overnight buswork change

      • Group similar needs on same day, put special needs on 0.5 day with another XP not needing RWM coil current

    • Iterate run plan, review XP by 2/11/08


Joint elm mitigation xp run plan strawman

Joint ELM Mitigation XP - Run plan (STRAWMAN)

Task Number of Shots

1) Create targets (i) below, but near and (ii) above ideal no-wall beta limit (control shots)

(use 125271 (large ELMs) as setup shot, 2 or 3 NBI sources, relatively high k ~ 2.0 or above to avoid strong rotating modes)

A) No non-axisymmetric field, 2-3 NBI sources, q95 ~ 82

B) Reduce q95 ~ 6(NOTE: attempt lower q95 than this?)2

2) Attempt ELM mitigation with DC fields

A) n = 2 + 3 fields 6

B) n = 2 fields, change phasing, amplitude4

C) n = 3 fields, change amplitude (change NBI torque???)4

D) n = 6 fields by producing primary n = 0 field 2

E) Try n = 1 (???); change NBI torque (???)4

3) Attempt ELM mitigation with AC fields

A) pre-programmed, match ELM frequency, not-propagating ( 20 < f(Hz) < 800)2

B) pre-programmed, match ELM frequency, co-propagating ( 20 < f(Hz) < 800)2

B) pre-programmed, match ELM frequency, counter-propagating ( 20 < f(Hz) < 800)2

C) n = 1 Br feedback, vary (i) gain (ii) phase8

4) Additional scans

Total 38

V1.0


Extra slides

Extra Slides


Exploratory approach to finding elm mitigation solution with midplane non axisymmetric coils

Exploratory approach to finding ELM mitigation solution with midplane non-axisymmetric coils

  • Goal

    • Demonstration of ELM mitigation with NSTX midplane RWM coil set

  • Approach (complementary to other proposed plans)

    • Application of broader n spectrum of DC fields

      • Non-standard coil configs: (i) turn off one coil, (ii) turn off 5 coils, (iii) turn off every other coil, (iv) slow pre-programmed toroidal propagation of setup (iii)

      • New “n = 2” applied field capability for 2008, vary phase

      • Perturbations away from “n = 1” control currents (which have n = 1,5 dominant), superposition of n = 1 – 3, higher n

      • Bonus: Can get NTV rotation braking data piggyback!

    • Application of AC fields

      • Pre-programmed toroidal propagation of several DC setups mentioned above

        • Might stimulate ELM to allow to transform large ELMs into smaller (acceptable) ELMs

        • Now examining existing ELM mitigation evidence from past RWM, NTV experiments

      • N = 1 feedback

        • Can best feedback configuration from 2007 alter ELM dynamics?

    • Take best approach above and run in closest ITER shape w/ELMS


Direction of applied n 1 traveling wave alters rwm stability

Direction of applied n=1 traveling wave alters RWM stability

  • Stronger RFA with co-flow field

  • RWM not destabilized

Field propagates with flow

Field propagates against flow

(co-flow)

(counter-flow)

80

60

40

20

0

RWM

Bp n=1(G)

Larger

RFA

smaller

RFA

Phase Bp n=1

360

240

120

0

1

0.5

0

-0.5

-1

IRWM(kA)

116940

116941

0.25 0.35 0.45 0.55

Time (s)

0.25 0.35 0.45 0.55

Time (s)

  • Weaker RFA with counter-flow field

  • Unstable RWM


Unstable rwm avoided with rapidly rotating n 1

40

30

20

10

0

Ft (kHz)

116941

116940

0.9 1.1 1.3 1.5

R (m)

0.9 1.1 1.3 1.5

R (m)

Unstable RWM avoided with rapidly rotating n = 1

  • Applied field in the direction of plasma flow:

    • RFA increases and rotation damps

    • n=1 internal mode triggered

    • Rigid rotor rotation profile; beta recovers

  • Applied field against the plasma flow:

    • RWM grows

    • Rapid, complete rotation and beta collapse

(applied field co-flow)

(counter-flow)

co-

bNno-wall (DCON)

counter

core rotation

counter

co-

co-

counter

0.0 0.2 0.4 0.6 0.8

Time (s)


  • Login