The IMACS dewar is being designed, fabricated, and assembled by Gerry Luppino (UH IfA) and GL Scientific, Honolulu, Hi.
The IMACS dewar incorporates several interesting features. Although no longer unusual, the dewar contains 8 SITe 2K x 4K pixel CCDs, arranged to form a 8K x 8K pixel focal plane array. The individual detectors will be aligned and coplanar to a few microns. The array will be cooled by a pair of APD CryoTiger closed-cycle coolers, which obviate the need for liquid nitrogen as a coolant. The focal plane array sits on a commercial, Physik Instrument X-Y stage, which provides +/- 100 microns of array position control for removing the effects of gravitational flexure. Finally, the array and X-Y stage sit on a large titanium flexure stage, which provides +/- 1 mm of focus motion control.
The latest fabrication images are shown below.
Focus drive components (ball screw, flange, bellows). 5/20/00
Focus drive bellows after e-beam welding. 5/20/00
Rear of dewar body showing vaccuum gauge and focus stage mounting flange. 5/20/00
Detector cooling straps (copper). 5/20/00
Front view showing main dewar body, handles, and array mounting plate. 4/24/00
Main body with side windows showing access to array, truss, and XY stage. 4/24/00
Side view through dewar body window. G10 truss is yellow. 4/24/00
Back view showing mounting surface for focus control stage, vaccuum fittings. 4/24/00
Array mounting plate and connectors to XY stage. 4/24/00
Dr. Luppino failed to mention that our dewar would be radioactive. This may simplify finding it in the dark... 4/24/00
A Mechanical Desktop (MD3) model of the IMACS dewar with side cover plates removed.
This image shows the dewar back plate supporting the focus and flexure control stages, which, via the yellow truss (G10 composite), in turn supports the focal plane array mounting plate (top, made of invar).
This image shows the large titanium focus stage (double flexure), the PI flexure control stage, and the G10 truss.
This image shows the back plate of the dewar, which supports the entire focal plane assembly, including the flexure and focus control stages.