A cryogenic payload for the 3rd generation of gravitational wave interferometers

► Cryogenics is one of key technologies of a third generation of interferometric gravitational wave detectors as in LCGT and ET projects. ► The results reported in this paper are the basis towards the realization of a full cryogenic interferometer. ► The behavior of a suspension prototype is studied both for optimizing the heat extraction from the mirror and the mirror control.