Nuno F. Loureiro

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Two-dimensional numerical simulations of the effect of background turbulence on 2D resistive magnetic reconnection are presented. For sufficiently small values of the re-sistivity (η) and moderate values of the turbulent power (), the reconnection rate is found to have a much weaker dependence on η than the Sweet-Parker scaling of η 1/2 and is even(More)
An efficient, iterative semi-implicit (SI) numerical method for the time integration of stiff wave systems is presented. Physics-based assumptions are used to derive a convergent iterative formulation of the SI scheme which enables the monitoring and control of the error introduced by the SI operator. This iteration essentially turns a semi-implicit method(More)
Recent work demonstrated that breaking the up-down symmetry of tokamak flux surfaces removes a constraint that limits intrinsic momentum transport, and hence toroidal rotation, to be small. We show, through MHD analysis, that ellipticity is most effective at introducing up-down asymmetry throughout the plasma. We detail an extension to GS2, a local δf(More)
The recent realization that Sweet-Parker current sheets are violently unstable to the secondary tearing (plasmoid) instability implies that such current sheets cannot occur in real systems. This suggests that, in order to understand the onset of magnetic reconnection, one needs to consider the growth of the tearing instability in a current layer as it is(More)
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