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2006
The Kamaboko III negative ion source, which was designed and built by JAERI, Naka, Japan, is a model 25% in linear dimensions of the reference design ion source for the International Thermonuclear Experimental Reactor ITER neutral beam injectors. The ion source is a magnetic multi-pole, arc discharge, source with 12 tungsten filaments. Cesium is ad…
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2006
Present day tokamaks are capable of generating toroidal flows approaching the ion sound speed. Such toroidal rotation is known to have a stabilising effect on resistive wall modes[1]. Here the effects of plasma rotation and diamagnetic drifts on the n = 1 internal kink mode and high n ballooning modes are presented with specific comparison to exper…
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2006
Optical interferometers are normally used in magnetically confined plasmas to measure the refractive index of the plasma by comparing the phase shift variation between a reference and a probe laser beam, from which the line-integrated electron density can be derived. Unfortunately, interferometric measurements are affected by fringe jumps, which ar…
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2006
Understanding the phenomenology captured in direct numerical simulation (DNS) of magnetohydrodynamic (MHD) turbulence rests upon models and assumptions concerning the scaling of field variables and dissipation. Here compressible MHD turbulence is simulated in two spatial dimensions by solving the isothermal equations of resistive MHD on a periodic …
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2006
The technology underlying a ceramic capacitive diaphragm gauge CDG manometer has been investigated for use as a microbalance for measurement of dust accumulation in next-step fusion devices such as ITER. Initial trials have confirmed in principle the use of CDG devices as dust microbalances and both the gauge head and electronics have been adapted …
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2006
The ability to predict the stability of fast-particle-driven Alfvén eigenmodes in burning fusion plasmas requires a detailed understanding of the dissipative mechanisms that damp these modes. In order to address this question, the linear gyro-kinetic, electromagnetic code L IGKA [1] is employed to investigate their behaviour in realistic tokamak g…
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2006
It is widely believed that transport barriers in tokamak plasmas are caused by radial electric-field shear, which is governed by angular momentum transport. Turbulence is suppressed in the barrier, and ion thermal transport is comparable to the neoclassical prediction, but experimentally angular momentum transport has remained anomalous. With this …
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2006
A new edge Thomson scattering diagnostic has been implemented at MAST to complement an existing high spatial resolution ruby laser system and the high time sampling core Nd:YAG system. The Nd:YAG system comprises of four independently controllable lasers. Scattered light from these lasers is viewed at large scattering angle 153° by a special optic…
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2006
This paper discusses an approach to modelling Edge Localised Modes (ELMs) in which toroidal peeling modes are envisaged to initiate a constrained relaxation of the tokamak outer region plasma. Relaxation produces both a flattened edge current profile (which tends to further destabilise a peeling mode), and a plasma-vacuum negative current sheet whi…
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2006
During a recent reversed toroidal field (B T) campaign at the Joint European Torus (JET), experiments were performed to investigate the effect on sawteeth of neutral beam injection (NBI)-driven toroidal plasma rotation counter to the direction of the toroidal plasma current and B T . A power scan at constant density has permitted analytical continu…
Showing 2251 - 2260 of 2590 UKAEA Paper Results