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CCFE-PR(17)482017
The ITER tokamak needs to sustain a plasma in a regime of high energy confinement (H-mode) to exceed fusion breakeven where power output exceeds input. H-mode plasmas are typically unstable to edge localised modes (ELMs), in which plasma escapes and strikes the plasma facing components. Scaled up to ITER, the energy released by ELMs can cause criti…
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CCFE-PR(17)462017
Tokamak plasma current start-up assisted by Electron Bernstein waves (EBW) has been demonstrated successfully in a number of experiments. The dynamic start-up phase involves a change in field topology, as the initially open magnetic field lines form closed flux surfaces (CFS) under the initiation of a plasma current. This change in field topology w…
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CCFE-PR(17)112017
This work presents the first evidence of helical flow in RFX-mod q(a) < 2 tokamak plasmas. The flow pattern is characterized by the presence of convective cells with m = 1 and n = 1 periodicity in the poloidal and toroidal direction, respectively. A similar helical flow deformation has been observed in the same device when operatedfas a Reversed…
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CCFE-PR(17)042017
Ion cyclotron emission (ICE) is detected during edge localised modes (ELMs) in the KSTAR tokamak at harmonics of the proton cyclotron frequency in the outer plasma edge. The emission typically chirps downward (occasionally upward) during ELM crashes, and is driven by confined 3MeV fusion-born protons that have large drift excursions from the plasma…
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CCFE-PR(16)622016
Spherical tokamaks (STs) typically have lower magnetic fields than conventional tokamaks, but similar mass densities. Suprathermal ions with relatively modest energies, in particular beam-injected ions, consequently have speeds close to or exceeding the Alfven velocity, and can therefore excite a range of Alfvenic instabilities. STs heated with neu…
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CCFE-PR(16)322016
A Fusion Nuclear Science Facility (FNSF) could play an important role in the development of fusion energy by providing the nuclear environment needed to develop fusion materials and components. The spherical torus/tokamak (ST) is a leading candidate for an FNSF due to its potentially high neutron wall loading and modular configuration. A key consid…
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CCFE-PR(16)162016
Divertor detachment in the TCV tokamak has been investigated through experiments and modelling. Density ramp experiments were carried out in ohmic heated L-mode pulses with the ion B drift directed away from the primary X-point, similar to previous studies [pitts2001]. Before the roll-over in the ion current to the outer strike point, C III and D? …
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CCFE-PR(16)612016
In the last three years, magnetic reconnection research in the MAST spherical tokamak achieved major progress by use of new 32 chord ion Doppler tomography, 130 channel YAG and 300 channel Ruby Thomson scattering diagnostics. In addition to the previously achieved high power plasma heating during merging, detailed full temperature profile measureme…
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CCFE-PR(16)532016
Fispact-II is a code system and library database for modelling activation-transmutation processes depletion-burn-up, time dependent inventory and radiation damage source terms caused by nuclear reactions and decays. The Fispact-II code, written in object-style Fortran, follows the evolution of material irradiated by neutrons, alphas, gammas, proto…
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CCFE-PR(16)282016
A poloidal tilting symmetry of the local nonlinear _f gyrokinetic model is demonstrated analytically and verified numerically. This symmetry shows that poloidally rotating all the flux surface shaping effects with large poloidal mode number by a single tilt angle has an exponentially small effect on the transport properties of a tokamak. This is sh…
Showing 191 - 200 of 530 UKAEA Paper Results