PACS IBDR

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PACS IBDR

• Budgets and Interfaces

Reinhard Katterloher
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Instrument Interfaces to S/C

• Mechanical interface FPU to OB
• Mechanical interface WE to SVM
• Mechanical interface BOLA to CVV
• Thermal interface FPU to S/C cooling system, FPU
  requires temperature level 0 and 1
• Electrical interface WE to S/C
• Electrical interface FPU to WE
• Optical interface FPU to telescope beam
• Optical interface FPU alignment cube to outside
  CVV alignment tools

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FPU and Interfaces Schematic
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FPU OB interface (view to PACS FPU from
below)
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Thermal Budget and Interface FPU - S/C cryostat

• FPU requires two temperature levels- level 0 at
  nominal 1.7K (max. 1.75K accepted)- level 1
  around 4K (max. 5.0K accepted)
• Other temperatures inside the FPU are produced
  autonomously (2.2K blue array/ 0.3K bolometers)
• Thermal coupling to level 0 via 4 heat straps
• Thermal coupling to level 1 via 3 heat straps
• FPU is thermally decoupled from OB by CFRP feet
• Thermal loads and final heat fluxes can be
  calculated using the PACS TMM combined with the
  cryostat TMM

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Dissipated Heat Loads (input to TMM)
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Electrical Budget and interface FPU WE S/C

• Harness as specified in PACS-MA-SP-001 has-
  total inside CVV 1100 wires 227 shields 30
  tbc overshields- total outside CVV/BOLA 1148
  wires 233 shields 30 tbc overshields
• Power consumption of WE see separate table
• Science data rate in PACS prime mode is 120 kbps
  average per day

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Mass and Size of Units
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Power Consumption on SVM
Peak power consumptions and inrush currents are
provided in IID-B CR-0011A Power dissipation in
BOLA on CVV is 0.2W