Preheating device for Isentropic Compression Experiments on GEPI

GEPI is a 3 MA, 500 ns, high-pulsed power driver operated by the CEA and primarily used for launching ramp compression waves in planar loads with stress levels up to 100 GPa. In order to enhance the ability to explore metallic phase diagrams over a wide range of thermodynamic paths, we have recently developed a device capable of pre-heating samples up to 1200 K. This device is based on inductive heating under primary vacuum and ensures a temperature uniformity of \textpm 10K across the sample. The main features of this heating device are presented, along with the various technical solutions which significantly simplified its insertion in a robust and reliable experimental configuration. Several experiments, carried out to date on various materials including iron and copper ramp-compressed starting from different initial temperatures, are presented as illustration.