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2013
Many models for anomalous transport consider the turbulent E × B transport arising from electrostatic micro-instabilities. In this paper we investigate whether the perturbed magnetic field that is associated with such instabilities at small but finite values of ß can lead to significant stochastic magnetic field transport. Using the tearing parit…
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2013
13MW of electron cyclotron current drive (ECCD) power deposited inside the q = 1 surface is likely to reduce the sawtooth period in ITER baseline scenario below the level empirically predicted to trigger neo-classical tearing modes (NTMs). However, since the ECCD control scheme is solely predicated upon changing the local magnetic shear, it is prud…
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2013
The materials engineering data base relevant to fusion irradiation is poorly populated and it has long been recognized that a fusion spectrum neutron source will be required, the facility IFMIF being the present proposal. Re-evaluation of the regulatory approach for the EU proposed DEMO device shows that the purpose of the source can be changed fro…
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2013
As part of preparations for the new Super-X divertor (SXD) on MAST, the influence of long divertor leg is modelled by SOL transport codes. The SOLPS5.0 package is used to study the effect of the expanded divertor in two dimensions and a comparison between the conventional geometry (standard short divertor) and the SXD geometry is presented. We focu…
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2012
Sawtooth control using electron cyclotron current drive (ECCD) has been demonstrated in ITER-like plasmas with a large fast ion fraction, wide q = 1 radius and long uncontrolled sawtooth period in DIII-D. The sawtooth period is minimized when the ECCD resonance is just inside the q = 1 surface. Sawtooth destabilization using driven current inside q…
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2011
Magnetohydrodynamic equilibrium states with a three-dimensional helical core are computed to model the MAST spherical tokamak and the RFX-mod reversed field pinch. The boundary is fixed as axisymmetric. The MAST equilibrium state has the appearance of an internal kink mode and is obtained under conditions of weak reversed central shear. The RFX-mod…
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2011
The aim of the Tore Supra tokamak is to address physics and technology issues of long pulse discharges. For this purpose, Tore Supra is equipped with two actively cooled Lower Hybrid Current Drive (LHCD) antennas (f = 3.7GHz), designed to operate in 1000s long pulses. One of these is the recently installed passive active multijunction (PAM) antenna…
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2011
The sawtooth instability in tokamak plasmas results in a periodic reorganization of the core plasma. A typical sawtooth cycle consists of a quiescent period, during which the plasma density and temperature increase, followed by the growth of a helical magnetic perturbation, which in turn is followed by a rapid collapse of the central pressure. The …
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2010
A long wavelength range infrared camera (LWIR) has been installed on MAST to compliment the existing medium wave infrared system. Simultaneous LWIR/MWIR temperature measurements have been made in the lower and upper divertors of MAST. As expected, the LWIR system is less sensitive to disturbances from hot spots on the surface. A thorough correction…
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2010
In this work, the radial transport of tracers in an H-mode run in the CUTIE code [A. Thyagaraja et al. , Phys. Plasmas 12 , 090907 (2005)] is analyzed globally. Several techniques are applied to the study of the trajectories performed by the tracers, measuring the degree of self-similarity in the motion and searching for long range spatial and temp…
Showing 81 - 90 of 107 UKAEA Paper Results