We have developed a filter exchange unit (FEU) and a shutter of Hyper Suprime-Cam (HSC). FEU consists of two parts; the alignment mechanism of the filter in the optical path and a jukebox of the filters. The alignment mechanism can guarantee 10 μm position stability with respect to the focal plane CCDs. On the exchange sequence, a motorized cart grabs and pushes the filter from the jukebox. Each jukebox has 3 slots and we have two identical jukeboxes. The operation is fully automated and the entire exchange sequence takes 16 minutes. Also, we developed the focal-plane shutter with 1,030 mm diameter envelope and 60 mm thickness while having 600 mm aperture. We report the detail of design and implementation of the shutter and FEU, and installation procedure of FEU.
Hyper Suprime-Cam (HSC) is the next generation wide-field imager for the prime focus of Subaru Telescope,
which is scheduled to receive its first light in 2011. Combined with a newly built wide-field corrector, HSC
covers 1.5 degree diameter field of view with 116 fully-depleted CCDs. In this presentation, we summarize the
details of the camera design: the wide-field corrector, the prime focus unit, the CCD dewar and the peripheral
devices. The wide-field corrector consists of 5 lenses with lateral shift type doublet ADC element. The novel
design guarantees the excellent image quality (D<sub>80</sub> <0".3) over the field of view. On the focal plane, 116 CCDs
are tiled on the cold plate which is made of Silicon Carbide (SiC) and cooled down to -100 degrees by two pulse
tube coolers. The system is supported by the prime focus unit which provides a precise motion of the system to
align the wide-field corrector and the CCD dewar to the optical axis of the telescope.
The next generation wide field camera HSC (Hyper Suprime-Cam) on Subaru telescope is planned to
cover 1.5 degree diameter field with a focal plane size about 650mm. To minimize the impact to the telescope,
the design for the elements of the camera is constraint to the tight space and weight limits. In order to fit the
available space, the screen winding shutter and petal shape filter exchanger are designed for the HSC. The
CFRP is used for the structure to minimize the load. In this report, the design and analysis for the shutter and
filter exchanger system will be presented. The result for the shutter membrane tests will also be discussed.