EUCLID GRISM WHEEL ASSEMBLY

摘要

This paper present a subsystem of the Near Infrared SpectroPhotometerrn(NISP) instrument of the Euclid mission:rnthe Grism Wheel Assembly (GWA). The Grating WheelrnAssembly (GWA) will provide the required grism interchangingrnfunctionalities. The mechanism will positionrninto the optical beam four different grisms: two groups ofrngrisms with different passband coating, each group willrnconsists into two identical grism with orthogonal dispersingrndirection respect to the optical beam. The main propertiesrnand performances of this subsystem will be shownrnsummarizing the study done into the Phase A. The "DogrnClutch Cryomechanism" is an evolution of the actuatorrndeveloped for the ground based astronomical instrumentrnVLT-VISIR properly adapted to the Euclid requirements.