Figure 13

2D magnetised torus evolution. Evolution of the 2D magnetised torus with resolution \(1{,}024\times512\) for times \(t/M\in\{300,1{,}000,2{,}000\}\). We show logarithmic rest-frame density (top), logarithmic plasma β (middle) and the logarithm of the magnetisation parameter \(\sigma=b^{2}/\rho\) (bottom). Magnetic field lines are traced out in the first panel using black contour lines. One can clearly make out the development of the MRI and evacuation of a strongly magnetised funnel reaching values of \(\beta< 10^{-5}\) and \(\sigma\approx10^{3}\).