Eddington Kick-Off

. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)

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EddiCam: The Eddington Photometric Camera

Preliminary Design Layout

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)

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Eddicam

Planet finding CCD layout Asteroseismology layout

FiltersFrame transfer covers

Eddington Kick-Off

. 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)

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)

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Eddicam

Eddicam Preliminary Layout

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. Vienna, September 17th, 2001 T.Muñoz/C.Laviada (INTA)

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Eddicam CCD Mask Assy Mechanical Concepts:

Slidding Concept

Cam/Rotating Concept

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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

Eddington Kick-Off

. 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