Eddington Kick-O ff . Vienna , September 17th, 2001 T.Muñoz/C.Lavia da (INTA) 1 EddiCam: The Eddington Photometric Camera Preliminary Design Layout
Dec 26, 2015
Eddington Kick-Off
. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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EddiCam: The Eddington Photometric Camera
Preliminary Design Layout
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
DPEPCE
CCU ROE
SHUTTER
COVERSCCDs
HEAT PIPES
Incoming light
FEE
LEDs
HEAT PIPES
Heaters
EddiCamCamera Unit
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
• CCD baseline characteristics– Format: 740 x 2900 pixels
– Pixel size: 27 x 27 µm2
– Chip size: 20 x 80 mm2
– Full well capacity: 1.6 Me-
– Minimum line readout time: 13 µs
– Frame transfer time: 20 ms
– Readout noise: 10 - 15 e- at 0.5 MHz
– Operational temperature: -80 / -100 C
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Planet finding CCD layout Asteroseismology layout
FiltersFrame transfer covers
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
• CCD array preliminary design– 16 + 4 CCDs covering the full FOV
– CCDs working in frame transfer mode for asteroseismology (short integrations on bright stars)
– CCDs working in full frame mode for planet finding(long integrations on weaker stars)
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
• CCD mosaic proposed by Marconi:
– 20 CCDs on individual INVAR packages
– Each CCD individually mounted on a large INVAR
baseplate
– All CCDs within ±10 µm from the baseplate:
no individual focussing required
– Flatness variation < 3 µm from +20 to -100 C
– Butting gap around 500 µm
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Prototype of CCD array proposed by Marconi
Eddington Kick-Off
. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Detail of individual CCD chip package
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
• EddiCam Camera Unit Preliminary Layout
– CCD Support Assembly– CCD Mask Assembly– Calibration Assembly– FEE Box– Support Structure
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Eddicam Preliminary Layout
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
CCD Support Assy
Calibration Assy
FEE Box
Support Structure Assy
CCD Mask Assy
Eddicam Explode View
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam CCD Support Assembly Primary Missions:
• Provide an accurate and stable support to the CCD Mosaic• Provide an effective thermal path between CCD´s and the heat sink I/F• Provide a cold trap for decontamination purpose
Bottom Face ViewTop Face View
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Cold Trap
CCD MosaicInvar Plate
Cold RingFlexible Thermal Links
CCD Support Assy Explode view
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam CCD Support Assembly Hot Points:
• Required flatness of the mosaic plane• Required alignment between CCD´s• Maximum butting gap (design based on three side buttable CCD)• Thermal stability control ( 0.1K/h):
-Completely passive (by mean of thermal equilibrium and thermal inertia)-Thermally controlled by mean of sensors/heaters
• Flexible thermal links: Copper/Aluminium straps Carbon Fibre straps(?)
Micro heat pipes• Thermal Switches for the baking mode(?):
CCD Mosaic cooling path disconnection could be required
Eddington Kick-Off
. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam CCD Mask Assy Missions:•Change between planet finding and asteroseismology operational modes
CCD Mask Assy Hot Points:• Single or Multiple actuation:
driver for actuator concept• Mask-CCD´s gap:
potential straylight sourcebaking mode
• If lubrication required:cleanliness control problem
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam CCD Mask Assy Mechanical Concepts:
Slidding Concept
Cam/Rotating Concept
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Calibration Assy Missions:•Provide dust protection during the AIV and Launch Phases•Provide a flat field light on the CCD plane for calibration
Calibration Assy Hot Points:• Single or Multiple actuation: Driver for actuator concept• If lubrication required: Cleanliness control• Straylight•If spectral information required: Devices included in this assy
High Impact on preliminary configuration concept
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
FEE Box:•Provide mechanical support to each preamps boards•Provide a dedicate thermal control system for heat dissipation•Provide protection against radiation
FEE Box Hot Points:• Mass and Envelope•Accessibility and integration with CCD´s•Thermal conductivity between electrical connections•Thermal isolation from CCD´s Supportand cooling design
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. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)
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Eddicam
Support Structure Assy Missions:•Provide a stiff and stable connection to the telescope•Provide support to the different elements of the camera unit•Provide support to the electrical and thermal devices from the telescope•Provide allocation to the refocusing system(?)
Support Structure Assy Hot Points:• High stable structure• Heat pipes and harness path from telescope to the unit•Focusing system: high impact on preliminary design