We propose to investigate the lateral transport of hot electrons along the wire surface driven by the RELAX 100 TW laser. By fielding the standard diagnostics of small angle X-ray scattering (SAXS), X-ray phase contrast imaging (PCI) and X-ray emission spectroscopy simultaneously, we plan to study the following multi-time scale processes ranging from femtoseconds to several tens of picoseconds: i) propagation and decay time of fast lateral and return currents along the target surface; ii) Ohmic heating, z-pinch effects and plasma expansion driven by the return current; iii) kinetic instability and MHD instability during the plasma expansion. SAXS and PCI provide complementary information of plasma dynamic density gradients sensitive to few nm and sub-micron respectively, while the plasma temperature will be characterized by the X-ray emission spectroscopy. The first proof-of-principle results obtained from our recent community experiment #2621 have demonstrated the feasibility.