Magnetohydrodynamic simulations of massive gas injection into Alcator C-Mod and DIII-D plasmas

Izzo, V.A.; Whyte, D.G.; Granetz, R.; Parks, P. B.; Hollmann, E. M.; Lao, L. L.; Wesley, J.C.

doi:10.1063/1.2841526

Cited by 70 publications

(66 citation statements)

References 15 publications

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“…It is plausible that background impurities such as Argon remaining from previous pulses (where Ar MGI was used) [12] provide this extra cooling. The need for background impurities to match experimental observations had already been identified for He MGI simulations in Alcator C-Mod and DIII-D with NIMROD [7].…”

Section: The Plasma Current Spikementioning

confidence: 99%

Progress in understanding disruptions triggered by massive gas injection via 3D non-linear MHD modelling with JOREK

Nardon

Fil

Hoelzl

et al. 2016

Plasma Phys. Control. Fusion

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3D non-linear MHD simulations of a D 2 massive gas injection (MGI) triggered disruption in JET with the JOREK code provide results which are qualitatively consistent with experimental observations and shed light on the physics at play. In particular, it is observed that the gas destabilizes a large m/n = 2/1 tearing mode, with the island O-point coinciding with the gas deposition region, by enhancing the plasma resistivity via cooling. When the 2/1 island gets so large that its inner side reaches the q = 3/2 surface, a 3/2 tearing mode grows. Simulations suggest that this is due to a steepening of the current profile right inside q = 3/2. Magnetic field stochastization over a large fraction of the minor radius as well as the growth of higher n modes ensue rapidly, leading to the thermal quench (TQ). The role of the 1/1 internal kink mode is discussed. An I p spike at the TQ is obtained in the simulations but with a smaller amplitude than in the experiment. Possible reasons are discussed.

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Section: The Plasma Current Spikementioning

confidence: 99%

Progress in understanding disruptions triggered by massive gas injection via 3D non-linear MHD modelling with JOREK

Nardon

Fil

Hoelzl

et al. 2016

Plasma Phys. Control. Fusion

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“…[382][383][384] The combination of codes is referred to as NIMRAD. Pure helium and pure neon injection experiments were modeled in the high plasma pressure, reactor-relevant regime.…”

Section: A Disruption Mitigationmentioning

confidence: 99%

20 years of research on the Alcator C-Mod tokamak

et al. 2014

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The object of this review is to summarize the achievements of research on the Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 and Marmar, Fusion Sci. Technol. 51, 261 (2007)] and to place that research in the context of the quest for practical fusion energy. C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since it began operation in 1993, contributing data that extends tests of critical physical models into new parameter ranges and into new regimes. Using only highpower radio frequency (RF) waves for heating and current drive with innovative launching structures, C-Mod operates routinely at reactor level power densities and achieves plasma pressures higher than any other toroidal confinement device. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing componentsapproaches subsequently adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated a) Paper AR1 1, Bull. Am. Phys. Soc. 58, 21 (2013). b) Invited speaker.

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“…Simulations of killer pellet injection [11,12,13] have been performed by coupling runaway models to pellet injection and impurity radiation models. Simulations of massive gas injection involving sophisticated fluid models [14,15] have also been made, but the inclusion of runaway effects is in its early stages. Often simpler 0D simulations are used in order to model experimental results [7,16].…”

Section: Introductionmentioning

confidence: 99%

Simulation of runaway electron generation during plasma shutdown by impurity injection in ITER

Fehér¹,

Smith²,

Fülöp³

et al. 2011

Plasma Phys. Control. Fusion

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Abstract. Disruptions in a large tokamak can cause serious damage to the device and should be avoided or mitigated. Massive gas or killer pellet injection are possible ways to obtain a controlled fast plasma shutdown before a natural disruption occurs. In this work, plasma shutdown scenarios with different types of impurities are studied for an ITER-like plasma. Plasma cooling, runaway generation and the associated electric field diffusion are calculated with a 1D-code taking the Dreicer, hot-tail and avalanche runaway generation processes into account. Thin, radially localised sheets with high temperature can be created after the thermal quench, and the Dreicer and avalanche processes produce a high runaway current inside these sheets. At high impurity concentration the Dreicer process is suppressed but hot-tail runaways are created. Favourable thermal and current quench times can be achieved with a mixture of deuterium and neon or argon. However, to prevent the avalanche process from creating a significant runaway current fraction, it is found to be necessary to include runaway losses in the model.

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Magnetohydrodynamic simulations of massive gas injection into Alcator C-Mod and DIII-D plasmas

Cited by 70 publications

References 15 publications

Progress in understanding disruptions triggered by massive gas injection via 3D non-linear MHD modelling with JOREK

Progress in understanding disruptions triggered by massive gas injection via 3D non-linear MHD modelling with JOREK

20 years of research on the Alcator C-Mod tokamak

Simulation of runaway electron generation during plasma shutdown by impurity injection in ITER

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