Journals

Showing 991 - 1000 of 1482 Journals Results
2009

The generation of zonal magnetic fields in laboratory fusion plasmas is predicted by theoretical and numerical models and was recently observed experimentally. It is shown that the modification of the current density gradient associated with such corrugations can significantly affect the stability of the tearing mode. A simple scaling law is derive…

Published
2009

Beam emission spectroscopy BES of the energetic deuterium D 0 heating beams can provide a means of characterizing the density turbulence in tokamak plasmas. First such measurements have been performed on the MAST spherical tokamak using a trial BES system, which shares the collection optics of the charge-exchange recombination spectroscopy system. …

Published
2009

In this paper, significant results in the heating and current drive domains obtained at JET in the past few years following systems upgrade and dedicated experimental time, will be reviewed. Firstly, an overview of the new Ion Cyclotron Resonance Frequency (ICRF) heating capabilities will be presented i.e. results trom the ITER-Like ICRF antenna (I…

Published
2009

Many of the ITER diagnostic systems will be mounted in the equatorial and upper ports of the torus, supported by removable structures known as 'port plugs'. The port plugs support the diagnostics and provide functions of baking, cooling, and neutron shielding. They must operate reliably in the demanding ultra-high vacuum, high radiation environment…

Published
2009

Electron Bernstein waves (EBW) have the potential to provide highly localized heating and current drive (CD). EBWs are predominantly electrostatic and they damp on electrons near electron cyclotron harmonics without momentum injection into the plasma. These features represent a powerful tool for understanding transport and stability phenomena by lo…

Published
2009

Finite temperature magnetic properties of iron thin films are investigated, up to ferro/paramagnetic transition. The coupled dynamics of atoms and magnetic moments is treated using large-scale spin-lattice dynamics (SLD) simulations. A comprehensive study of surface and bulk magnetic properties is conducted, to investigate their dependences on temp…

Published
2009

It has been suggested that radial transport in turbulent plasmas may be nonlocal and non-Markovian. In this paper the transport of test particles in the global, electromagnetic, three-dimensional code CUTIE [A. Thyagaraja and et al. , Phys. Plasmas 12 , 090907 (2005)] is characterized. This code includes a nonlinear feedback mechanism between the m…

Published
2009

This paper reports on a modern implementation of a Langmuir probe method that was first proposed in the 1950’s. The system directly measures the first and second derivative of the I-V characteristic and determines the EEDF. This probe offers many advantages over existing systems that rely on numerical differentiating and data smoothing techniques…

Published
2009

Over the past two decades, the increase in neutral-beam heating and particle production in magnetically confined fusion plasmas has led to an increase in energetic particle driven mode activity, much of which has an electromagnetic signature which can be detected by the use of external Mirnov coils. Typically, the frequency and spatial wave number …

Published
2009

Using the JET A2 ICRF antennas [1], experiments were carried out to assess the performance of three different dipole phasing configurations relevant for the operation of the ICRF antenna in ITER. Three similar discharges with dipole, "symmetric dipole" and "super dipole" phasings were compared. In the "super dipole" case, higher coupling was confir…

Published