Filter Wheel
The filter wheel has 18 positions: 10 imaging filters, 4 coronagraphic diaphragms/filters, 1 neutral density filter, 1 double prism, 1 lens and 1 clear/blind position (counterweight of prism). The system has to operate in the cryovacuum of 7k during a ground-test (3 years) and also in space (up to 10 years). The design is based on the ISOPHOT wheel mechanisms flown on ESA’s Infrared Space Observatory (ISO). The filter wheel assembly houses a wheel disc carrying all the optical elements. Rotation is realised by a central two-phase torque motor (allows for bi-directional movement). The system is electrically supplied by the ICE.
The picture belows shows the CEA Filter Wheel Assembly delivered to MPIA
The picture belows shows the Filter Wheel motor in the construction phase at MPIA
Filter wheels are designed and built at the Max-Plank-Institut fur Astronomie
Max-Plank-Institut of Astronomie