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2005
The mechanism of four nonlinearly interacting drift or Rossby waves is used as the basic process underlying the turbulent evolution of both the Charney-Hasegawa-Mima-equation CHME and its generalized modification GCHME. Hasegawa and Kodama’s concept of equivalent action or quanta is applied to the four-wave system and shown to control the distrib…
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2005
The European Activation File is the source of nuclear data for fusion activation calculations that has been developed in Europe. In order to trust the calculations made with the data, validation is essential. A key part of this is the comparison of the EAF data with integral experiments made in fusion relevant neutron spectra on a wide range of mat…
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2005
The usual calculation of Dreicer [Phys. Rev. 115 , 238 (1959); 117 , 329 (1960)] generation of runaway electrons assumes that the plasma is in a steady state. In a tokamak disruption this is not necessarily true since the plasma cools down quickly and the collision time for electrons at the runaway threshold energy can be comparable to the cooling …
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2005
The interpretation of EBW emission from spherical tokamaks is nontrivial. We report on a 3D simulation model of this process that incorporates Gaussian beams for the antenna, a full wave solution of EBW-X and EBW-X-O conversions using adaptive finite elements, and EBW ray tracing to determine the radiative temperature. This model is then used to in…
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2005
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2005
The statistical properties of the dissipation process constrain the analysis of large scale numerical simulations of three-dimensional incompressible magnetohydrodynamic ( MHD ) turbulence, such as those of Biskamp and Müller [ Phys. Plasmas 7 , 4889 ( 2000 )] . The structure functions of the turbulent flow are expected to display statistical self…
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2005
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2005
Frequency sweeping (chirping) of high frequency magnetohydrodynamic modes is widely observed in tokamak plasmas. In this paper observations of chirping in neutral-beam-heated plasmas in the Mega-Amp Spherical Tokamak (MAST) [A. Sykes, R. J. Akers, L. C. Appel and et al. , Nucl. Fusion 41 , 1423 (2001)] are considered, and it is shown that these may…
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2005
Operation with tritium plasma led to contamination of the JET in-vessel components with tritium at a level exceeding 12kBq/g, which is the Low Level Waste (LLW) threshold in the UK. Carbon tiles used at JET for protecting the pumped divertor and inner wall against heat and neutron flux create one of the Intermediate Level Waste (ILW) streams to dea…
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2005
Recently, it was shown that intermittency observed in magnetic fusion devices is caused by large-scales events with high radial velocity reaching about 1/10th of the sound speed s called avaloids or blobs [G. Antar and et al. , Phys. Rev. Lett. 87 065001 (2001)]. In the present paper, the poloidal distribution of turbulence is investigated on the M…
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