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2003
We investigate the distribution of fluctuations in solar irradiance when integrated over the full disk, obtained using extreme ultraviolet / soft X-ray observations from the SOHO CELIAS / SEM instrument. This time series sums over both the contributions of single distinguishable flares, and of many other processes. By detrending we select events wi…
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2003
The existing regulatory framework in France provides a full and coherent licensing basis to permit ITER to be build and operated at Cadarache. The specific sitting studies including the submission of the first step of licensing documentation for ITER offers an early assessment of fusion power plants. The regulatory procedure begins with the release…
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2003
The transport of angular momentum due to neutral atoms in the tokamak edge is calculated and shown to be sensitive to the poloidal location of the neutrals. In the absence of external momentum sources, the edge plasma is predicted to rotate spontaneously in the opposite direction to the plasma current, at a speed proportional to the radial ion temp…
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2003
The original description of alpha particle driven instabilities in the Tokamak Fusion Test Reactor in terms of toroidal Alfven eigenmodes (TAEs) remained inconsistent with three fundamental characteristics of the observations: (i) the variation of the mode frequency with toroidal mode number, (ii) the chirping of the mode frequency for a given toro…
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2003
Studies of type 1 ELMy H-mode pedestals are carried out using 0 D and 1.5 D approaches. In the 0 D study, predicted pedestal temperatures are compared with 533 data points. The pedestal temperature models, with pedestal width based on magnetic and flow shear stabilization and neutral penetration, yield an RMSE of 32% and 53.4%, respectively, when c…
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2003
The linear stability of high-toroidal-number drift-ballooning modes in tokamaks is investigated with a model that includes resistive and viscous dissipation, and assumes the mode frequency to be comparable to both the sound and diamagnetic frequencies. The coupled effect of ion drift waves and electron drift-acoustic waves is shown to be important,…
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2003
Ever since conception of the Vacuum Arc Centrifuge (VAC) in 1980, periodic fluctuations in the ion saturation current and floating potential have been observed in Langmuir probe measurements in the rotation region of a VAC. Our theoretical and experimental research suggests that these fluctuations are in fact a pressure-gradient driven drift mode. …
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2003
The Berk–Breizman augmentation of the Vlasov–Maxwell system is widely used to model self-consistent resonant excitation and damping of wave fields by evolving energetic particle populations in magnetic fusion plasmas. The key model parameters are the particle annihilation rate, which drives bump-on-tail structure, and the linear wave damping ra…
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2003
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2003
Combined operation of Lower Hybrid (LH) and Ion Cyclotron Resonance Frequency (ICRF) waves can result in a degradation of the LH wave coupling, as observed both in the Tore Supra and JET tokamaks. The reflection coefficient on the part of the LH launcher magnetically connected to the powered ICRF antenna increases, suggesting a local decrease in th…
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