1 / 5

NSTX 2010 Experimental Proposal: Peeling-Ballooning Stability Dependence on Plasma Triangularity

NSTX. Supported by. NSTX 2010 Experimental Proposal: Peeling-Ballooning Stability Dependence on Plasma Triangularity. College W&M Colorado Sch Mines Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics New York U Old Dominion U ORNL PPPL

denise
Download Presentation

NSTX 2010 Experimental Proposal: Peeling-Ballooning Stability Dependence on Plasma Triangularity

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. NSTX Supported by NSTX 2010 Experimental Proposal: Peeling-Ballooning Stability Dependence on Plasma Triangularity College W&M Colorado Sch Mines Columbia U Comp-X General Atomics INEL Johns Hopkins U LANL LLNL Lodestar MIT Nova Photonics New York U Old Dominion U ORNL PPPL PSI Princeton U Purdue U SNL Think Tank, Inc. UC Davis UC Irvine UCLA UCSD U Colorado U Maryland U Rochester U Washington U Wisconsin Culham Sci Ctr U St. Andrews York U Chubu U Fukui U Hiroshima U Hyogo U Kyoto U Kyushu U Kyushu Tokai U NIFS Niigata U U Tokyo JAEA Hebrew U Ioffe Inst RRC Kurchatov Inst TRINITI KBSI KAIST POSTECH ASIPP ENEA, Frascati CEA, Cadarache IPP, Jülich IPP, Garching ASCR, Czech Rep U Quebec Aaron Sontag, Oak Ridge National Lab FY2010 NSTX Research Forum Dec. 1-3, 2009

  2. Proposal: Alter Peeling-Ballooning Stability Boundary by Varying Plasma Triangularity 1.2 0.8 0.4 0.1 Edge current [(jmax+jsep)/2<j>] 3 4 5 6 7 8 Normalized Pressure Gradient () NSTX peeling-ballooning stability as calculated by ELITE for a discharge with Type I ELMs 10 Ballooning stability as calculated by PEST 5 bN dlower = 0.3 dlower = 0.4 dlower = 0.2 0 0 0.25 0.5 dupper NSTX peeling-ballooning stability inconsistent with ELITE calculations • ELMs observed even though g/(w*/2) << 1 PEST indicates ballooning may be important • max. stable bN roughly proportional to avg. d Reduced d can increase ballooning instability drive • high-d opens up 2nd stability at low A 2

  3. XP 942 Successfully Affected ELM Stability with dlower modification dlower decrease coincident with transition to small ELMs • drsep unchanged until well after small ELM regime (0.46 s) Further d reduction needed to approach ballooning boundary • PEST indicates n=3 still most unstable mode • shot development required going shape with decreased stability dupper scan also needed • go to higher k, Z0 > 0 plasma, or reduce outer gap 3

  4. XP Plan: Continue d scan from XP 942, independently varying dupper & dlower • Decreased d possible with increased outer gap • more modeling required for this scenario • XP 942 target was low-k (~1.9) LSN • difficult to affect dupper with large separation from control coils • dupper always slightly less than dlower • ISOLVER modeling shows more control of dupper achievable at increased-k • Use PF1AU to push/pull dupper • Fix PF1s & 2s, PCS control of PF3s & PF5 • increase k request • Vary dupper at fixed dlower • vary upper squareness request

  5. Duration & Required Diagnostics • XP could be performed in 1 day • Required diagnostics • CHERS (beam blips in HHFW-only discharges) • USXR arrays • magnetics • Thomson scattering • EFIT (w/MSE) • Da • Desired diagnostics • edge reflectometer • two color USXR

More Related