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2011
Pedestal profiles that span the ELM cycle have been obtained and used to test the idea that the pedestal pressure gradient in MAST is limited by the onset of Kinetic Ballooning Modes (KBMs). During the inter-ELM period of a regularly type I ELM-ing discharge on MAST, the pressure pedestal height and width increase together while the pressure gradie…
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2011
It is well known that stabilization of the resistive wall mode (RWM) may allow fusion power to be significantly increased for a given magnetic field in advanced tokamak operation. The principle of stabilization of the RWM by rotation has been established both experimentally and theoretically. Recent experimental results have indicated stabilization…
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2011
Stabilization of the resitive wall mode (RWM) may allow fusion power to be doubled for a given magnetic field in advanced tokamak operation. Experimental evidence from DIII-D and other machines suggests that plasma rotation can stabilize the RWM. Several authors (Finn 1995 Phys. Plasmas 2 3782, Bondeson Xie 1997 Phys. Plasmas 4 2081) have construct…
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2011
Derek Robinson was a leading UK plasma physicist of his generation. After an early success in measuring the electron temperature in the ZETA plasma through the Thomson scattering of laser light, he became a key member of the team from Culham Laboratory sent to Moscow in 1968 to verify the high temperatures claimed by the Russians for their T3 tokam…
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2011
It is shown that drift wave plasma turbulence in the electromagnetic regime can significantly affect the zonal flow dynamics and drive zonal fields. A new interpretation of the effect of the zonal fields on the zonal flow stability is given as previous analytic predictions are shown to be inadequate for accurately describing the numerical results. …
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2010
A Thomson scattering diagnostic designed to measure both edge and core physics has been implemented on MAST. The system uses eight Nd:YAG lasers, each with a repetition rate of 30 Hz. The relative and absolute timing of the lasers may be set arbitrarily to produce fast bursts of measurements to suit the time evolution of the physics being studied. …
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2009
The formation of neoclassical tearing modes (NTMs) severely limits the performance of a tokamak plasma by increasing the radial particle and heat fluxes from the core and can even lead to a plasma disruption. Indeed, NTMs are a serious consideration for the next step device, ITER. The appearance of a finite NTM magnetic island requires an initial â…
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2009
The H-mode pedestal characteristics on MAST are measured in a variety of Connected Double Null (CDN) and Single Null Divertor (SND) discharges. In CDN discharges the edge density pedestal width in spatial co-ordinates is similar on both the high and low field sides suggesting that the width may be determined by neutral penetration. However, in SND …
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2009
Tearing mode stability is normally analysed using MHD or two-fluid Braginskii plasma models. However for present, or future, large hot tokamaks like JET or ITER the collisionality is such as to place them in the banana regime. Here we develop a linear stability theory for the resonant layer physics appropriate to such a regime. The outcome is a set…
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2009
This workshop on transport in fusion plasmas is the thirteenth in a series. Previously they have been held under the auspices of the EU and US Transport Task Forces (TTFs), with J Connor as the EU TTF chair. However, the EU Transport Task Force has now been subsumed into the EFDA (European Fusion Development Agreement) Topical Group for Transport (…
Showing 81 - 90 of 136 UKAEA Paper Results