Standardized CCD and MCT detector mounting configurations B

Standardized CCD and MCT detector mounting configurations B. C. Bigelow, UM Physics 2/2/05 2/3/05 Bruce C. Bigelow -- UM Physics

Si. C Focal Plane Concept • Consider Si. C for focal plane baseplate — Si. C superior to Moly in virtually all material properties — Si. C 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 Si. C material, and optically flat mirrors established — Substantial weight savings for focal plane assembly, bipods, etc. 2/3/05 Bruce C. Bigelow -- UM Physics 2

Si. C Focal Plane Concept • Consider Si. C for focal plane baseplate Material Molybdenum Si. C (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/m. K) 138 300 Properties 2/3/05 Bruce C. Bigelow -- UM Physics 3

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

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

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

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