Abstract
We present a design of an optical cell dedicated to study the water properties near the liquid-gas critical point using the DECLIC-CNES instrument on board the International Space Station. This designed cell satisfies safety requirements for high pressure and high temperature operating conditions of the high temperature insert (HTI). This design is optimized for using high-resolution and high-speed optical diagnostics, local temperature controls and measurements of the DECLIC instrument, in particular to observe and to analyze the thermal and density response of critical water after a transient heating produced by one heat pulse actuator. Illustrations of the high-level performances are provided by the preliminary results obtained during the Earth's tests of the flight model of the HTI insert.
