Shocks in highly supersonic astrophysical jets at all scales are excellent scenarios for studying non-thermal processes. In this seminar I will present our recent results on diffusive shock acceleration and magnetic field amplification in jets from protostars and active galactic nuclei. In the former case, the coexistence of an adiabatic and a radiative shock is a promising scenario for enhancement of the gamma-ray emission.
Furthermore, the parameters for scaled laboratory experiments are very much in line with plasma conditions achievable in high-power laser facilities opening the door to new means for studying protostellar jets. In the latter case, we find that the maximum energy of electrons accelerated in the hotspots of powerful radiogalaxies cannot be constrained by synchrotron losses as usually assumed, unless the jet density is unreasonably large. I will present a mechanism for limiting the maximum energy of electrons to the observed values (TeV), and show that the same constraint applies also to protons. Last but not least, I will show that shocks in the backflows of powerful radioglaxies can accelerate particles up to the Hillas energy even when the turbulence is not sufficiently strong for Bohm diffusion to apply. This result places radiogalaxies as strong candidates for Ultra High Energy Cosmic Ray sources.