▎ 摘　　要

We study inelastic energy relaxation in graphene for low energies to find out how electrons scatter with acoustic phonons and other electrons. By coupling the graphene to superconductors, we create a strong dependence of the measured signal, i.e., critical Josephson current, on the electron population on different energy states. Since the relative population of high-and low-energy states is determined by the inelastic scattering processes, the critical current becomes an effective probe for their strength. We argue that the electron-electron interaction is the dominant relaxation method and we estimate a scattering time tau(e-e) = 0.1 ... 1 ps at T = 500 mK, 1-2 orders of magnitude smaller than predicted for normal two-dimensional diffusive systems.