UKAEA Papers

Showing 1241 - 1250 of 1892 UKAEA Paper Results
2012

At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70–500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The …

Published
2012

Parallel transport associated with Type I ELM filaments in the scrape-off layer (SOL) is studied by means of three computational approaches – fluid, Vlasov and particle-in-cell (PIC). These techniques are benchmarked for convective transients by analyzing power fluxes at the target. In spite of kinetic effects due to fast electrons which are not …

Published
2012

In preparation for ITER, JET has been upgraded with a new ITER-like wall (ILW), whereby the main plasma facing components, previously of carbon, have been replaced by mainly Be in the main chamber and W in the divertor. As part of the many diagnostic enhancements, a new, survey, visible spectroscopy diagnostic has been installed for the characteriz…

Published
2012

We present a combined experimental and computational study of high-temperature magnetic properties of Fe-Cr alloys with chromium content up to about 20 at.%. Magnetic Cluster Expansion method is applied to model the magnetic properties of random Fe-Cr alloys, and in particular the Curie transition temperature, as functions of alloy composition. We …

Published
2011

Major developments on MAST have enabled important advances in support of ITER and the physics basis of a spherical tokamak (ST) based component test facility (CTF), as well as providing new insight into underlying tokamak physics. For example, L-H transition studies benefit from high spatial and temporal resolution measurements of pedestal profile …

Published
2011

The behaviour of the turbulence in magnetic fusion plasmas is discussed in the framework of dimensional analysis. Three main dimensionless parameters are identified, which directly affect the adiabatic response of the plasma and hence control the electron response. They were originally introduced by Scott [B. Scott, Plasma Phys Control. Fusion, 39,…

Published
2011

Mechanisms of arc formation have been analyzed and the critical electric fields for the multipactor effect calculated, compared to the experimental values and found to be within the normal operational space of the LH system on JET. It has been shown that the characteristic electron energy (20-1000)eV for the highest multipactor resonances (N=4-9) a…

Published
2011

Axisymmetric plasma equilibria with toroidal flow are investigated using a two-fluid analysis, taking into account the presence of momentum and current drive, together with dissipative effects. The equilibria are described by a set of three equations describing the spatial variation of poloidal magnetic flux, plasma pressure and toroidal magnetic f…

Published
2011

In the traditional picture of plasticity in bcc metals, edge dislocations have been assumed to play a minor role due to their high mobility with respect to screw dislocations, which then control plastic flow. 1 2 111{110} edge dislocations indeed fit this description, as it has been shown by way of numerous atomistic simulations. However, 1 2 111{1…

Published