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Don Mitchell 30 SEP 2019. CMB-S4 and Hex Camera Design Comparisons. Overview – Hex Camera Shown. Overview CMB-S4 Shown. Overview – Size Comparison. CMB-S4 ~10,000 Lbs 85 Detector modules. Hex Camera ~16,000 Lbs 133 Detector modules. Overview – Size Comparison.
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Don Mitchell 30 SEP 2019 CMB-S4 and Hex CameraDesign Comparisons
Overview – Hex Camera Shown Don Mitchell | CMB-S4 and TMA Design Comparisons
Overview CMB-S4 Shown Don Mitchell | CMB-S4 and TMA Design Comparisons
Overview – Size Comparison CMB-S4 ~10,000 Lbs 85 Detector modules Hex Camera ~16,000 Lbs 133 Detector modules Don Mitchell | CMB-S4 and TMA Design Comparisons
Overview – Size Comparison Both systems use the same detector module design Don Mitchell | CMB-S4 and TMA Design Comparisons
Typical Outer Lens Layout on Front Plate Don Mitchell | CMB-S4 and TMA Design Comparisons
Outer Lens / Clamp Design Don Mitchell | CMB-S4 and TMA Design Comparisons
Outer Lens / Clamp Design Don Mitchell | CMB-S4 and TMA Design Comparisons
Outer Lens Clamp • Aligns on center of mounting hole • Curved features auto-center each window • Bottoms out when fully in position • Rubber pads prevent over-stressing window Don Mitchell | CMB-S4 and TMA Design Comparisons
Hex Camera Module Overview 50k 4k 1k 100mk Don Mitchell | CMB-S4 and TMA Design Comparisons
12.7 mm thick plates: 100 MPa < 138 Mpa(allowable) Don Mitchell | CMB-S4 and TMA Design Comparisons
Hex Front Plate: FE Analysis Summary 31.75 mm thick front plate111.38MPa < 138 MPa Don Mitchell | CMB-S4 and TMA Design Comparisons
Overview: CMB-S4 Don Mitchell | CMB-S4 and TMA Design Comparisons
CMB-S4 Front Plate: FE Analysis Summary • 3” thick plate • 3/4” between ports • 137 MPa, 2.77 mm Quarter Symmetry Don Mitchell | CMB-S4 and TMA Design Comparisons
300k Vessel Assembly • Front Plate: 2,882 lbs • Central Vessel: 3,779 lbs • Rear Plate: 1,450 lbs • Vessel total weight: 8,111 lbs Don Mitchell | CMB-S4 and TMA Design Comparisons
50k Shield Assembly • Estimated weight of the 50k shield made of aluminum is 315 lbs. Don Mitchell | CMB-S4 and TMA Design Comparisons
4k Shield Assembly • Estimated weight of the 4k assembly made of aluminum is 365 lbs. • Estimated weight of 85 lens on 4k plate is 67 lbs (material of lens considered is silicon). Don Mitchell | CMB-S4 and TMA Design Comparisons
1k Shield and Rear Detector Assembly • Estimated weight of the 1k plate, 1k shield and 85 focal plane Cone made of aluminum is 352.4 lbs. • Estimated weight of rest of material connected to 1k plate (lyot, lens, carbon fiber rod) is 80 lbs. Don Mitchell | CMB-S4 and TMA Design Comparisons
100 mK Cooling Bar Weldment • Estimated weight of the 100mk copper weldment is 180 lbs. Don Mitchell | CMB-S4 and TMA Design Comparisons
Miscellaneous • G10 plates • Carbon Fiber Rods • Electronics • Cables • etc. Don Mitchell | CMB-S4 and TMA Design Comparisons
Serviceability • With the rear plate and rear shields removed, each detector module can be easily removed and serviced. • Cable connections and 100mk heat sinks are accessible. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation 50k shield shown installed – supported by 300k vessel with G10 support posts. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Begin constructing the coldmass.1k shield plate with cable and 100mk connection hardware. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Install detector modules Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation 1k shield shown with detector modules installed. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Install the 100mk cooling weldment – shown. Also install cables – not shown. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Install the 1k cover plate and carbon fiber connecting rods. – Rods used to connect 1k assembly to 4k plate. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Attach 1k assembly to 4k plate. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Install 4k side and rear shields. Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation • Install coldmass into the vessel – supported by G10 connecting plates • Install cooling straps • Connect all cables Don Mitchell | CMB-S4 and TMA Design Comparisons
Installation Install front and rear plate assemblies. Don Mitchell | CMB-S4 and TMA Design Comparisons
Various section views Don Mitchell | CMB-S4 and TMA Design Comparisons
Various section views Don Mitchell | CMB-S4 and TMA Design Comparisons
Pros and Cons: Hex Camera Design Pros: • Modular, pull entire module to service and swap-out • Easier shipping to remote site Cons: • Loss of tight packing factor between modules • All services must be rear-mounted • Access for cryogenics is very limited • Tight installation of heat shields – multiple shields (7 sets) • Larger cryogenic loads with multiple losses to 300k • Complicated design to fit all components – very tight! • Overall heavier design than CMB-S4 Don Mitchell | CMB-S4 and TMA Design Comparisons
Pros and Cons: CMB-S4 Design Pros: • One assembly – lighter than hex camera design • Ease of serviceability from rear access • External vessel faces are accessible for mounting cryogenic, electronic, and alignment systems • Room for heat shields, cables, etc. • Good Packing factor • Compact design with fewer losses to 300k - less cooling Cons: • Large, singular assembly to handle • Mounted Cryocoolers and Dil-Fridge have limited angular operating positions Don Mitchell | CMB-S4 and TMA Design Comparisons