Journals

Showing 991 - 1000 of 1605 Journals Results
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. …

Published
2011

Among dust particles of various origins collected in the MAST vessel, large quantities of carbon nanoparticles are observed. They are produced in the coldest plasma regions from the nucleation of carbonaceous species originating from physical and chemical erosion of the graphitic plasma facing components. On the other hand, laboratory plasmas studi…

Published
2011

Experiments have been performed on MAST using internal (n=3) resonant magnetic perturbation coils. The application of the RMPs to L-mode discharges has shown a clear density pump out when the field line pitch angle at the low field side of the plasma is sufficiently well aligned with the applied field. The application of the RMPs before the L-H tra…

Published
2011

Intensities and detailed spectral shapes of γ-ray emission peaks were successfully reproduced using a physics model combining the kinetics of the reacting ions with a detailed description of the nuclear reaction differential cross sections for populating the L1-L8 14 N excitation levels yielding the observed γ-ray emission. The results provide a …

Published
2011

Angular scanning of electron Bernstein wave emission (EBE) has been conducted in MAST. From EBE measurements over a range of viewing angles, the angular position and orientation of the B-X-O mode conversion (MC) window can be estimated, giving the pitch angle of the magnetic field in the MC layer. The radial position of the corresponding MC layer i…

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