1. Standardized CCD and MCT detector mounting configurations
B. C. Bigelow, UM Physics
2/2/05

2. SiC Focal Plane Concept
Consider SiC for focal plane baseplate
SiC superior to Moly in virtually all material properties
SiC has 5 times the specific stiffness, and 1/3 the density of Moly
Standard detector packages with spring preload mountings allow use of current detector package materials
No thermal compensator / flexure mounts required
Space heritage for SiC material, and optically flat mirrors established
Substantial weight savings for focal plane assembly, bipods, etc.
2/3/05
Bruce C. Bigelow -- UM Physics

3. SiC Focal Plane Concept
Consider SiC for focal plane baseplate
Material
Properties
Molybdenum
SiC (CVD)
E (GPa)
330.0
466.0
Yield (MPa)
415.0
470.0
Density (kg/m^3)
10220
3210
CTE (RT, PPM/K)
5.35
2.20
K (RT, W/mK)
138
300
2/3/05
Bruce C. Bigelow -- UM Physics

4. Bruce C. Bigelow -- UM Physics
Focal Plane Concept
CTE comparison (courtesy of Pat Jelinsky):
2/3/05
Bruce C. Bigelow -- UM Physics

5. SiC Focal Plane Concept
2/3/05
Bruce C. Bigelow -- UM Physics

6. SiC Focal Plane Concept
2/3/05
Bruce C. Bigelow -- UM Physics

7. SiC Focal Plane Concept
Conclusions
SiC is a viable option for focal plane baseplate
Standardized detector packages are compatible with SiC
Substantial weight savings are possible
Lots more to do if SNAP project is interested in SiC:
Add spectrograph, guider detectors, BITE optics, etc.
Add cold shield, “concentrator” electronics, radiator interface, etc.
Detailed design of baseplate
FEA of baseplate
2/3/05
Bruce C. Bigelow -- UM Physics