First observation of ELM pacing with vertical jogs in a spherical torus

Gerhardt, S. P.; Ahn, J.-W.; Canik, J.; Maingi, R.; Bell, R. E.; Gates, D.; Goldston, Robert James; Hawryluk, R. J.; Blanc, Baptiste; Ménard, J.; Sontag, A. C.; Sabbagh, S. A.; Tritz, K.

doi:10.1088/0029-5515/50/6/064015

Cited by 27 publications

(23 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The amplitude and toroidal mode number of any magnetic braking [105][106][107][108][109][110] applied to the plasma are recorded, as are the status of n=1 RWM control [52,109,111], n=1 dynamic error field correction [78], and n=3 error field correction [112]. Also recorded are any non-standard techniques applied to the plasma, including vertical jogs for ELM pacing [113], pulsed 3D fields for ELM pacing [114][115][116], or isoflux [117,118] control of the divertor X-and strike-points [119,120]; these are not necessary disruptive techniques, but a large fraction of the discharges utilizing them were for development, when the disruption rate was higher. Finally, the database records if the discharge was taken during a phase with "good conditions", or during a phase of machine commissioning at the beginning of the run or with known bad vacuum or PFC conditions.…”

Section: : Analysis Methodsmentioning

confidence: 99%

Disruptions, Disruptivity, and Safer Operating Windows in the High-β Spherical Torus NSTX

Gerhardt¹,

Diallo²,

Gates³

et al. 2012

View full text Add to dashboard Cite

Section: : Analysis Methodsmentioning

confidence: 99%

Disruptions, Disruptivity, and Safer Operating Windows in the High-β Spherical Torus NSTX

Gerhardt¹,

Diallo²,

Gates³

et al. 2012

View full text Add to dashboard Cite

“…240 It should be also noted that this ELM triggering is also known as the ELM pacing, and other techniques such as the repetitive lithium granular injection and vertical jogs have been successfully developed. 244,245 VII. BOUNDARY PHYSICS…”

Section: -39mentioning

confidence: 99%

Recent progress on spherical torus research

Ono

Kaita

2015

Physics of Plasmas

View full text Add to dashboard Cite

The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A = R0/a) reduced to A ∼ 1.5, well below the normal tokamak operating range of A ≥ 2.5. As the aspect ratio is reduced, the ideal tokamak beta β (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as β ∼ 1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation κ, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of an attractive fusion energy power source. Since the start of the two mega-ampere class ST facilities in 2000, the National Spherical Torus Experiment in the United States and Mega Ampere Spherical Tokamak in UK, active ST research has been conducted worldwide. More than 16 ST research facilities operating during this period have achieved remarkable advances in all fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era.

show abstract

“…The initial results on TCV [142] and subsequent results on NSTX [145] showed ELM triggering with upward movement of the magnetic axis, consistent with increased edge current leading to the destabilization of current driven modes. However the results on ASDEX-Upgrade and JET showed preferential ELM triggering with downward movement of the axis [23,143].…”

Section: Vertical Jogsmentioning

confidence: 70%

“…These techniques include supersonic molecular beam injection (SMBI) [73,136,137], edge electron cyclotron heating (ECH) [73,138,139], lower hybrid heating and/or current drive (LHH, LHCD) [140,141], controlled periodic oscillations of the vertical centroid position (jogs) [73,[142][143][144][145][146], ELM pace-making via periodic MPs [147][148][149][150][151][152][153][154], modification of edge profiles and stability with lithium wall coatings [18,[155][156][157][158][159][160][161][162][163][164][165][166][167], and the use of naturally occurring small ELM regimes [23]. Each of these is described below.…”

Section: Other Elm Control: Active and Naturally Occurringmentioning

confidence: 99%

See 1 more Smart Citation

Physics news on the Internet (based on electronic preprints)

Eroshenko¹

2013

Phys.-Usp.

View full text Add to dashboard Cite

Large edge localized modes (ELMs) typically accompany good H-mode confinement in fusion devices, but can present problems for plasma facing components because of high transient heat loads. Here the range of techniques for ELM control deployed in fusion devices is reviewed. Two strategies in the ITER baseline design are emphasized: rapid ELM triggering and peak heat flux control via pellet injection, and the use of magnetic perturbations to suppress or mitigate ELMs. While both of these techniques are moderately well developed, with reasonable physical bases for projecting to ITER, differing observations between multiple devices are also discussed to highlight the needed community R&D. In addition, recent progress in ELM-free regimes, namely quiescent H-mode, I-mode, and enhanced pedestal H-mode is reviewed, and open questions for extrapolability are discussed. Finally progress and outstanding issues in alternate ELM control techniques are reviewed: supersonic molecular beam injection, edge electron cyclotron heating, lower hybrid heating and/or current drive, controlled periodic jogs of the vertical centroid position, ELM pace-making via periodic magnetic perturbations, ELM elimination with lithium wall conditioning, and naturally occurring small ELM regimes.

show abstract

First observation of ELM pacing with vertical jogs in a spherical torus

Cited by 27 publications

References 62 publications

Disruptions, Disruptivity, and Safer Operating Windows in the High-β Spherical Torus NSTX

Disruptions, Disruptivity, and Safer Operating Windows in the High-β Spherical Torus NSTX

Recent progress on spherical torus research

Physics news on the Internet (based on electronic preprints)

Contact Info

Product

Resources

About