Interaction of relativistic magnetized electrons with obstacles

Using a laser pulse from the OMEGA EP laser system focused to an intensity of $\sim10^{19}$Wcm$^{-2}$ we generate hot electron plumes on the surface of 25$\mu$m thick Al targets with high magnetization due to self-generated fields, given by $\sigma_{cold} = B^2/\mu_0n_em_ec^2 \approx 1$. These plumes expand at $\sim$c and interact with obstacles in the form of holes, or ``blobs'' of glue on the target. This interaction is probed using time-resolved proton radiography which allows for the measurement of fields in the plane of the target. The proton radiographs are analyzed using standard radiograph inversion codes and are compared to 2D and 3D particle-in-cell simulations.