scholarly journals Projections of H-mode access and edge pedestal in the SPARC tokamak

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
J. W. Hughes ◽  
N. T. Howard ◽  
P. Rodriguez-Fernandez ◽  
A. J. Creely ◽  
A. Q. Kuang ◽  
...  
Keyword(s):  
Plasma Discharge ◽  
Tokamak Plasma ◽  
Strong Equilibrium ◽  
Full Field ◽  
Auxiliary Power ◽  
Peak Energy ◽  
Edge Localized Mode ◽  
Edge Localized Modes ◽  
Localized Mode ◽  
Mitigation Techniques

In order to inform core performance projections and divertor design, the baseline SPARC tokamak plasma discharge is evaluated for its expected H-mode access, pedestal pressure and edge-localized mode (ELM) characteristics. A clear window for H-mode access is predicted for full field DT plasmas, with the available 25 MW of design auxiliary power. Additional alpha heating is likely needed for H-mode sustainment. Pressure pedestal predictions in the developed H-mode are surveyed using the EPED model. The projected SPARC pedestal would be limited dominantly by peeling modes and may achieve pressures in excess of 0.3 MPa at a density of approximately 3 × 1020 m−3. High pedestal pressure is partially enabled by strong equilibrium shaping, which has been increased as part of recent design iterations. Edge-localized modes (ELMs) with >1 MJ of energy are projected, and approaches for reducing the ELM size, and thus the peak energy fluence to divertor surfaces, are under consideration. The high pedestal predicted for SPARC provides ample margin to satisfy its high fusion gain (Q) mission, so that even if ELM mitigation techniques result in a 2× reduction of the pedestal pressure, Q > 2 is still predicted.

Edge-localized mode control by electron cyclotron waves in a tokamak plasma

2012 ◽  
Vol 52 (3) ◽  
pp. 032004 ◽  
Author(s):  
J.X. Rossel ◽  
J.-M. Moret ◽  
S. Coda ◽  
O. Sauter ◽  
T.P. Goodman ◽  
...  
Keyword(s):  
Electron Cyclotron ◽  
Tokamak Plasma ◽  
Mode Control ◽  
Edge Localized Mode ◽  
Localized Mode ◽  
Electron Cyclotron Waves

scholarly journals Structure and dynamical steady state of the peeling mode in edge-localized mode-free, high-confinement tokamak plasmas

2021 ◽  
Author(s):  
Kensaku Kamiya ◽  
Kimitaka Itoh ◽  
Nobuyuki Aiba ◽  
Naoyuki Oyama ◽  
Mitsuru Honda ◽  
...  
Keyword(s):  
Steady State ◽  
Direct Evidence ◽  
Limit Cycle Oscillation ◽  
Tokamak Plasmas ◽  
Mode Structure ◽  
Laboratory Plasma ◽  
Edge Localized Mode ◽  
Edge Localized Modes ◽  
Localized Mode ◽  
Cycle Oscillation

Abstract Explosive dynamical events in controlled-nuclear-fusion devices (known as edge-localized modes) display many similarities to solar-flare events on the sun, revealing a new connection between laboratory plasma physics and astronomy. However, to date there has been no direct evidence for the peeling mode structure, due to the lack of decisive diagnostics. Here we report the first evidence for the structure and dynamical steady state of a peeling mode for low-n edge-harmonic oscillations (EHOs) in the quiescent H-mode. EHOs are dominated by the fundamental mode (1fEHO) at both the low- and high-field sides. 1fEHO edge perturbations are confirmed to have kink parity and exhibit the frozen-in-condition predicted by a linear stability analysis. The envelope signal of the 1fEHO mode exhibits repeated cycles of growth and damping to the order of a few hundred Hz associated with small changes in an edge gradient, and results are quantitatively consistent with a limit-cycle-oscillation model.

scholarly journals Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

2014 ◽  
Vol 21 (6) ◽  
pp. 062302 ◽  
Author(s):  
S. C. Chapman ◽  
R. O. Dendy ◽  
T. N. Todd ◽  
N. W. Watkins ◽  
A. J. Webster ◽  
...  
Keyword(s):  
Signal Phase ◽  
Edge Localized Mode ◽  
Localized Mode ◽  
Relationship Of

scholarly journals Particle Dynamics in the RMP Ergodic Layer under the Influence of Edge Plasma Turbulence

10.14311/1831 ◽  
2013 ◽  
Vol 53 (4) ◽  
Author(s):  
Matúš Kurian ◽  
Ladislav Krlín ◽  
Pavel Cahyna ◽  
Radomír Pánek
Keyword(s):  
Plasma Turbulence ◽  
Edge Plasma ◽  
Tokamak Plasma ◽  
Edge Region ◽  
Ion Dynamics ◽  
Plasma Dynamics ◽  
Complex Processes ◽  
Edge Localized Modes ◽  
Particle Simulations ◽  
Practical Implications

The complex processes in edge tokamak plasma are affected (among others) both by resonant magnetic perturbation (RMP) and by plasma turbulence. RMP is nowadays considered to be a candidate for the mitigation of the edge-localized modes (ELMs). The effect of plasma turbulence inthe edge region has not been studied yet. Since both RMP and plasma turbulence should influence plasma dynamics, studies of their simultaneous effect have potential practical implications. Using a simplified model of the turbulence and single-particle simulations, we discovered that its effect at realistic amplitudes changes the ion dynamics significantly. We expect that the turbulence has a similar effect on electrons, thus potentially influencing the ELM mitigation mechanism.

scholarly journals Edge-localized mode dynamics and transport in the scrape-off layer of the DIII-D tokamak

2005 ◽  
Vol 12 (7) ◽  
pp. 072516 ◽  
Author(s):  
J. A. Boedo ◽  
D. L. Rudakov ◽  
E. Hollmann ◽  
D. S. Gray ◽  
K. H. Burrell ◽  
...  
Keyword(s):  
Edge Localized Mode ◽  
Localized Mode

Physical design of a new set of high poloidal mode number coils in the EAST tokamak

2022 ◽  
Author(s):  
Liang Liao ◽  
Yunfeng Liang ◽  
Shaocheng Liu ◽  
Huaxiang Zhang ◽  
Xiang Ji ◽  
...  
Keyword(s):  
Magnetic Topology ◽  
Magnetic Perturbation ◽  
Perturbation Field ◽  
Low Field ◽  
Flexible Working ◽  
Magnetic Spectrum ◽  
Edge Localized Mode ◽  
Field Edge ◽  
Localized Mode ◽  
Spectrum Characteristic

Abstract An external resonant magnetic perturbation (RMP) field, an effective method to mitigate or suppress the edge localized mode (ELM), has been planned to be applied on the ELM control issue in ITER. A new set of magnetic perturbation coils, named as high m coils, has been developed for the EAST tokamak. The magnetic perturbation field of the high m coils is localized in the midplane of the low field side (LFS), with a spectrum characteristic of high m and wide n, where m and n are the poloidal and toroidal mode numbers, respectively. The high m coils generates a strong localized perturbation field. Edge magnetic topology under the application of high m coils should have either a small or no stochastic region. With the combination of the high m coils and the current RMP coils, flexible working scenarios of the magnetic perturbation field are available, which is beneficial for ELM control exploration on EAST. Numerical simulations have been carried out to characterize the high m coil system, including the magnetic spectrum and magnetic topology, which shows a great flexibility of magnetic perturbation variation as a tool to investigate the interaction between ELM and external magnetic perturbation.

Direct evidence of E × B flow changes at the onset of resonant magnetic perturbation-driven edge-localized mode crash suppression

2019 ◽  
Vol 59 (6) ◽  
pp. 066033 ◽  
Author(s):  
Jaehyun Lee ◽  
Y.M. Jeon ◽  
Y. In ◽  
G.Y. Park ◽  
G.S. Yun ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Magnetic Perturbation ◽  
Edge Localized Mode ◽  
Localized Mode ◽  
Flow Changes
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