UKAEA Journals

Showing 1 - 8 of 8 Journals Results
2016
CCFE-PR(16)19

ELM control may be essential to develop ITER scenarios with a reasonable lifetime of divertor components, whilst ELM pacing may be essential to develop stationary ITER scenarios with a tungsten divertor. Resonant magnetic perturbations (RMPs) have mitigated ELMs in high collisionality plasmas in JET. The efficacy of RMPs in mitigating the ELMs is f…

Preprint Published
2015
CCFE-PR(15)84.

Within the single fluid resistive magnetohydrodynamic model, systematic toroidal modelling efforts are devoted to investigate the plasma response induced screening of the applied external 3D magnetic field perturbations in the presence of sheared toroidal flow. One particular issue of interest is addressed, when the local flow speed approaches zero…

Preprint Published
2014

The three dimensional plasma boundary displacements induced by applied nonaxisymmetric magnetic perturbations have been measured in ASDEX Upgrade, DIII-D, JET, MAST and NSTX. The displacements arising from applied resonant magnetic perturbations (RMPs) are measured up to ±5% of the minor radius in present day machines. Good agreement can be found …

Published
2013

All current estimations of the energy released by type I ELMs indicate that, in order to ensure an adequate lifetime of the divertor targets on ITER, a mechanism is required to decrease the amount of energy released by an ELM, or to eliminate ELMs altogether. One such amelioration mechanism relies on perturbing the magnetic field in the edge plasma…

Published
2013

Sustained ELM mitigation has been achieved using RMPs with a toroidal mode number of n=4 and n=6 in lower single null and with n=3 in connected double null plasmas on MAST. The ELM frequency increases by up to a factor of eight with a similar reduction in ELM energy loss. A threshold current for ELM mitigation is observed above which the ELM freque…

Published
2011

Recent experiments show the impact of Resonant Magnetic Perturbations on the density [O Schmitz et al Plasma Phys. Control. Fusion 50 124029 (2008); T E Evans et al Nucl. Fusion 48 024002 (2008); A Kirk et al Nucl. Fusion 50 024002 (2008); Y Liang et al Phys. Rev. Lett. 98 265004 (2007)], leading to a so-called density pump-out. Previous comparison…

Published
2010

Multiple resonances in the edge-localized mode (ELM) frequency (f ELM ) as a function of the edge safety factor q 95 have been observed for the first time with an applied low n (1/41; 2) field on the JET tokamak. Without an n 1/4 1 field applied, f ELM increases slightly from 20 to 30 Hz by varying the q 95 from 4 to 5 in a type-I ELMy H-mode plasm…

Published
2007

Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external n 1 perturbation field generated by four error field correction coils located far from the plasma. During the application of the n 1 field the ELM frequency increased by a factor of 4 and the amplitude of the D signal decreased. The energy loss per ELM…

Published