FPU Struts, Filter Wheel, Calibration Source

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FPUStruts, Filter Wheel, Calibration Source

• D.Kampf, Dr. Roland Graue
• Kayser-Threde GmbH

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FPU Suspension

• Mechanical/thermal Decoupling Isostatic
  Suspension with 6 Struts
• X-Translation, Rotation about Z 3 Struts
• Z/Y - Translation and Rotation 1 Strut/2 Struts
• Dimensions
• Cross Section/Length Ratio 50 mm2/70 mm
• Material (Baseline) Stainless Steel
  for Struts and Fittings
• Mass (w/o contingency) 1.5 kg

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Photoconductor Detector Suspension

• Mechanical/Thermal Decoupling Isostatic
  Suspension with 6 Rods
• X-Translation, Rotation about X 3 Struts
• Z/Y - Translation and Rotation 2 Struts/1
  Strut
• Dimensions
• Cross Section 13 x 2 mm2
• Length approx. 40 mm
  excl. Fittings
• Material (baseline) UD Kevlar 49 (0o
  -Orientation)
• Epoxi Matrix
• Ti 6 Al - 4V Fittings
• Mass (w/o Contingency) 0.42 kg

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Filter Wheel Assembly Design

• Unlimited Angle of Rotation
• 2 Preloaded, Dry, Gold coated Bearings (GRW)
• Rotor for 2 (optional 4) filters
• Cryotorquer Drive
• Total Mass 0.580 kg
• Rotor Inertia 0.11 gm2
• Dynamic Straylight Baffle

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Filter Wheel Cryotorquer Drive

• Brushless Motor with Magnets Positioned at the
  Rotor
• Cryotorquer Drive Design
• 12 Poles
• 24 Magnets (Samarium-Cobalt)
• 2 Phases (Each Redundant)
• 12 x 180 Cu-Coil Windings
• Stator with 4 Hall - Sensors, Two for Each of the
  Coil Package

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FW Assembly
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FW Bearing / Housing
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Cross section of the motor
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(No Transcript)
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Part-winding 1 (Phase 1)
Part-winding 2 (Phase 2)
Arrangement of the coils
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Principle of driving
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Technical description
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Filter Wheel Cryotorquer Drive - Contd

• Temperature Range (op.) 3 - 313 K
• Rotor Positioning by One Hall Sensor (Red.) and
  One Magnet at Each Stop (Powerless Dormitory Mode
  During Measurement Time)

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Cryotorquer Breadboard
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Filter Wheel Torquer Status

• Breadboard Tested at LHe-Temperatures
• Torquer Constant 0.3 Nm/A (Per Stator Package)
• Operational Current 0.25 A (Per Phase and Stator
  Package)
• Power Dissipation lt10 mWs (per Position Change)
• 25 mW (max)

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Filter Wheel Assembly

• Mass
• Stator 75 g
• Rotor 265 g
• Bearings 20 g
• Filter Wheel 100 g
• Mechanical Support 120 g
• 
  __________________________________________________
  _______
• Total (w/o Contigency) 580 g

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Flow diagram for Q-tests cryomotor
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Calibration Sources

• Outer Diameter 50 mm
• Aperture Diameter 12 mm
• Temperature 90 - 115 K
• Long Term Stability 25 mK (13 bit Resolution)
• Mass (w/o contingency) 0.14 kg (2)

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Assembly
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Baffle
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PT500/1000 Suspension
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Calibration Source Design

• Redundant Heat Source and Temperature Sensor (PT
  100/ PT 500 tbc), 4 wire method
• Aluminum Semispheres Coated with Highly
  Reflective Surface (Ni, Gold)
• Highly Reflective Scatter Plate (Ni, Gold) with
  200 µm rms Surface Roughness
• Collimating Source Mirrors to Increase the Flux
  Homogeneity

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ICD Status