Grism cryogenic mount for the Euclid-NISP mission

摘要

The spectroscopic channel of the Euclid Near Infrared SpectroPhotometer (NISP) relies on four grisms mounted on a wheel via Invar mounts. The mount design was studied to maintain the optical performances and alignment at cryogenic operating temperature (120K), and to survive launch vibrations. We designed two stages of radially compliant blades: one set of 9 blades is bonded to the Silica grism and the second set of 3 blades is located at interface points with the wheel. Severe packaging and mass constraints yielded us to design a ring mount with strong weight relief. In fall 2013 we proceeded to thermal cycling (323K-105K), vibration tests (10.7 g rms) to successfully qualify the grism mount in the Euclid environment. Thanks to detailed finite element analyses, we correlated simulations and tests.