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2013
Numerical simulations of interchange turbulence in the Scrape-Off Layer are performed in a regime relevant for a specific L-mode MAST (Mega Ampere Spherical Tokamak) discharge. Such a discharge was diagnosed with a reciprocating arm equipped with a Gundestrup probe. A detailed comparison of the average and statistical properties of the simulated an…
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2013
The maintenance requirements for the equipment in the ITER Neutral Beam Cell requires components to be lifted and transported within the cell by remote means. To meet this requirement, the provision of an overhead crane with remote handling capabilities has been initiated. The layout of the cell has driven the design to consist of a monorail crane …
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2013
The LIDAR Thomson scattering concept was proposed in 1983 and then implemented for the first time on the JET tokamak in 1987. A number of modifications were performed and published in 1995, but since then no major changes were made for almost 15 years. In 2010 a refurbishment of the diagnostic was started, with as main goals to improve its performa…
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2013
In the merging-compression method of plasma start-up, two flux-ropes with parallel toroidal current are formed around in-vessel poloidal field coils, before merging to form a spherical tokamak plasma. This start-up method, used in the Mega-Ampere Spherical Tokamak (MAST), is studied as a high Lundquist number and low plasma-beta magnetic reconnecti…
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2013
In body-centered-cubic (bcc) crystals, 1/2{111} screw dislocations exhibit high intrinsic lattice friction as a consequence of their nonplanar core structure, which results in a periodic energy landscape known as the Peierls potential UP. The main features determining plastic flow, including its stress and temperature dependences, can be derived di…
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2012
The VUV/XUV spectral region is particularly rich in lines emitted by plasmas with temperatures = 30 keV used in fusion research. Examples are presented of analyses of JET tokamak data involving C VUV/XUV radiation. In the first, the C IV divertor emission is modelled, with agreement between theory and experiment to within the measurement accuracy o…
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2012
The application of resonant magnetic perturbations with toroidal mode number n = 4 or n = 6 is observed to result in a significant increase in ELM frequency, despite a reduction in the edge pressure gradient. A picture for how type-I ELMs are mitigated, or destabilised, when magnetic perturbations are applied is proposed. Despite the magnetic pertu…
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2012
In fusion negative ion sources, the negative ions are formed on the caesiated plasma grid predominantly by hydrogen atoms from the plasma. The space charge of the negative ions leaving the wall is not fully compensated by incoming positive ions and at high enough emission a virtual cathode is formed. This virtual cathode limits the flux of negative…
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2012
The paper is a tribute to Nicol Peacock and has a focus on interests and developments at Culham Laboratory from ~ 1970 when Nicol led the UKAEA spectroscopy team. The paper charts a little of the evolution of these models and their data through the seventies and eighties on into this century at Culham. The paper concludes with the state of efforts …
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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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