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Dietrich Baade & ODT: Optical Detector Systems at ESO
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Optical Detector Systems at the
European Southern ObservatoryDietrich Baade
&Optical Detector Team (ODT)
Work at ESO on infrared detectors covered in:
Dorn et al. Finger et al. Mehrgan et al. Beletic et al.
Dietrich Baade & ODT: Optical Detector Systems at ESO
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The ODT Themes
• Shift in emphasis from scientific imaging to signal sensing: Without AO, ELTs will not bring any improvement.
• The MAD adaptive optics system tests enabling technology with bright natural guide stars.
• The OPTICON project with e2v L3 Vision technology aims to push this towards the ultra-low noise domain.
• The New General detector Controller (NGC) is a key stepping stone.
• More to come
VLT 2nd generation instruments:• X-shooter – the 0.3-to-2.4 μm rapid-response spectro-cannon• MUSE – the cosmic inventory taker
VLT projects in their own right but with an additional view of getting ready for OWL:
OmegaCAM for the VLT Survey Telescope (VST)
Dietrich Baade & ODT: Optical Detector Systems at ESO
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Multi-conjugated Adaptive Optics Demonstrator
• MAD tests two wavefront-sensing (WFS) concepts:
Reiss et al.
o star oriented, using multiple Shack-Hartmann (SH) systemso layer oriented (LO), using multiple pyramids
• 3 SHWFS + 2 LOWFS detector systems with e2v CCD39 devices (80 x 80 pixels)• Only one method used at a time• One FIERA controller• Up to 400 frames/s (500 frames/s with 2x2 binning)• Considerably exceeds original FIERA spec of 1 Mpixel/s • Read noise: ~7 e-
Dietrich Baade & ODT: Optical Detector Systems at ESO
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Next-generation Wavefront Sensing: OPTICON and e2v L3 Vision Technology
AO systems for 2nd-gen. VLT instruments and OWL require:• >1,000 actuators (→ >1,000 x 6x6 pixels)• ~1 kHz frame rate• negligible read noise even when photon noise ~100%• high movability (→ no real cryogenics → dark current) OPTICON project received funding from EU Commission CCD220 being developed by e2v
1 system foreseen for HAWK-I, 4 for MUSE
Downing et al.
StoreArea
Image Area
240x12024□µm
StoreArea
Image Area
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OP 1
OP 2 GainRegisters
OP 3
OP 4 GainRegisters
OP 8GainRegisters
OP 7
OP 6GainRegisters
OP 5
StoreAreaStoreArea
Image Area
240x12024□µm
StoreArea
Image Area
240x12024□µm
OP 1OP 1
OP 2 GainRegisters
OP 2 GainRegisters
OP 3OP 3
OP 4 GainRegisters
OP 4 GainRegisters
OP 8GainRegisters
OP 8GainRegisters
OP 7OP 7
OP 6GainRegisters
OP 6GainRegisters
OP 5OP 5
Dietrich Baade & ODT: Optical Detector Systems at ESO
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OmegaCAM (1° x 1° imager)
• Three FIERAs and 32 (+4) e2v CCD44-82 devices
• Very robust since first switch-on
• The coordination of autoguiding, closed-loop wavefront sensing, and shutter control is one of the show pieces.
• Built as designed
• Commissioning in 2006
• Strict attention to safety
• Extensive detector characterization on ESO’s test bench
• Innovative cooling system very effective
Iwert et al.
Lizon et al.
Christen et al. (2x)
Dietrich Baade & ODT: Optical Detector Systems at ESO
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X-shooter
• Basically a single-mode VLT Cassegrain instrument for singular events (`point and shoot´)
• Simultaneous wavelength coverage 0.3 – 2.4 μm• First ESO instrument to bridge the 1-micron barrier• 2 optical arms (e2v CCD44-82 and MIT/LL CCID-20)• 1 IR arm (Rockwell Hawaii-2 RG)
• 1 IRACE and 1 FIERA controller each• FIERA software defines 2 fully independent virtual cameras on one common DFE• Approaching Final Design Review• Commissioning in 2008
Dietrich Baade & ODT: Optical Detector Systems at ESO
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• First optical instrument to use NGC
• 2nd-generation cryostat head
• Prototype detector system at the end of 2006
Multi-unit Spectroscopic Explorer (MUSE)
• Twenty-four separate detector systems
• 4K x 4K CCDs (or 2 x 1 mosaics)
• 465 – 930 nm: high red response is mission critical
• Need to save mass and volume
• Must ease AIT
• Reliability will be vital
Reiss et al.
Dietrich Baade & ODT: Optical Detector Systems at ESO
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PULPO2 housekeeping unit with enhanced • shutter ( ) and temperature control• temperature and pressure monitoring
Cryostat Cleanliness and Control
Plasma cleaning: • fast, effective, low risk, low operating cost• excellent results with big OmegaCAM cryostat
Deiries et al.
Geimer et al.
H20 exorcism• baking of CCDs in gas stream • accidental (re-)discovery
Reif et al.
Dietrich Baade & ODT: Optical Detector Systems at ESO
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New General detector Controller (NGC)
• In the decade since 1998, a total of 30 FIERA and IRACE systems will be deployed.
• Extremely successful (nearly negligible telescope downtime) but some other limitations:
Meyer et al. Cumani et al.
• mass, volume, power dissipation
• obsolete components
• voltage range and swing
• speed, number of channels
• 2 successes (= 2 costs)
Reyes et al.
a
• Proto-type of joint successor NGC has seen `first light´• First deployments: KMOS (2009) and MUSE (2011)