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WIYN: NOAO User’s CommitteeOctober 13, 2004
Wisconsin, Indiana, Yale, NOAO
Photo by Amy Eckert, Discover Magazine
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Instrumentation at WIYN Currently supported general-use instruments
MiniMosaic (4Kx4K) imager OPTIC (4Kx4K) imager [50% availability from J. Tonry] WTTM (2Kx2K) tip/tilt corrected imager [always on] Hydra [always on] Densepak Sparsepak
Near-term upgrades Hydra rebuilt last year for reliability and maintenance Bench upgrades for throughput gains of 2-3X
VPH gratings (740 line in-hand; 3550 line in 6 months)
New CCD (finer pixels, faster readout, better red/blue)
Short FL, off-axis collimator
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Off-axis collimator design completed awaiting final consensus between project scientist and optical designer
740 line VPH grating ready to be tested – deferred to react to CCD failures and to focus on Hydra commissioning
3550 line VPH grating designed by Matt Bershady R > 20,000 at 510.6 nm; optimized for 450-550 nm glass purchased (250mm x 500mm x 30mm) Fabrication by CSL (Belgium); delivery by December 2004
Project web page updated Web Page
CCDs being tested (2600x4000 x 12 micron), contract with Univ of Arizona in place to thin, package, and test CCDs
Status – Bench
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Instrumentation on 2+ Year Track
WHIRC – Funded by STScI, WIYN, and (hopefully) NSF 2Kx2K NIR imager for WTTM 0.09” pixels for near-diffraction limited imaging Expected availability – mid-2006 Being built at STScI (Margaret Mexiner, Don Figer)
QUOTA – NSF funded 8Kx8K imager with OT CCDs (OTAs) 16 arcmin FOV Expected availability – mid-2006
ODI – Funding from WIYN (thus far), but NSF proposals to be written
32Kx32K imager with OTAs Details to follow
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WHIRC SummaryWIYN High Resolution InfraRed
Camera
Wavelength range 0.8 – 2.5 m
Plate scale 0.09”/pixel
Object plane From WTTM
Focal plane Hawaii 2RG (2K2 with 18 m pixels)
Image size Diffraction– or WTTM–limited PSF
Pupil location Accessible for cold Lyot stop
Achromaticity (goal)No refocusing between filters(WTTM prohibits telescope refocusing)
FiltersUp to 14 filters (J, H, Ks, numerous narrowband, eg. Brγ, HeI, H2, CO, perhaps some redshifted)
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WHIRC Performance - K
H Band, Center of Field
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0.00 0.05 0.10 0.15 0.20 0.25 0.30
Radius (arcsec)
EE
WIYNWTTMWHIRC 0.12"/pxlWHIRC 0.06"/pxlDiffr. limitHST
1 = 1.493 m
2 = 1.649 m
3 = 1.806 m
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QUOTA and ODI
ODI (2005) 32K x 32K Array -- Uses 64 OTAs
QUOTA (2004) “Quad Orthogonal Transfer Array” –
8K x 8K prototype to test new CCDs, controllers, software
Uses 4 OTAs – each is 4Kx4K
16”
Diagonal ~22.5 inches; Corrector ~26 inches diam
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Motivation:Excellent Image Quality Over 1°
WIYN produces great images WIYN has a natural 1° field of view Based on Tip/Tilt Performance at WIYN (Claver)
Tip/tilt improves seeing by ~15% in FWHM (typically about 0.14”) RIZ medians become ~ 0.52”, 0.43”, 0.35” Atmosphere decorrelates at 2 arcmin: degrades 0.32” images 10%
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OTCCD pixelstructure Basic OTCCD cell
Orthogonal Transfer Array (OTA)
OTA:8x8 array of OTCCDs
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Summary of OTA Properties
64 independent 480x494 CCDs Individual addressing of CCDs 2 arcmin field of view at LSST Bad columns confined to cells Point defects are tolerated
Cells with bright stars guide stars, or read fast, up to 30 Hz, to avoid blooming, or for time studies
8 video channels – 2s readout
Intercell gaps (0.1-0.3 mm; 1-3”); dithering required
Inter-OTA spacings: ~2 mm (20”)
5cm
12 um pixels = 0.11” at WIYN
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QUOTA and ODI:Orthogonal Transfer CCD Arrays
A collaborative effort between: MIT Lincoln Laboratory (Burke) Semiconductor Technology Associates (Bredthauer)
Univ of Hawaii / PanSTARRS (Tonry, Luppino) WIYN Observatory (Jacoby) Univ of Arizona / Imaging Technology Laboratory (Lesser)
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OPTIC: The OTA’s Ancestor Example – 300s R-band image
3 of 4 guide regions selected Read at 10-50 Hz Tip/tilt correct remaining pixels
CCD Format 2 – 2Kx4K OT CCDs 4 high-speed read zones 4 science zones
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OPTIC: A Time Domain Application
Quick readout of selected regions Enables the 10-50 Hz time domain for CCDs Example – planet transits
0.3s samples binned to 60s Relative accuracy ~ 6E-4 Approaches HST (1E-4)
Planet Transit
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STA CCD Array Configuration
8x8 Array of elements 480 x 494 Subcells allow for
increased busing area 3840 x 3952 pixels per OTA 336μ x 132μ streets (30x11
pix)
49.48 mm
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Packaging
Designed by G. Luppino and M. Lesser Fabricated by Kyocera; being assembled by Luppino
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Handling
Provides safe handling Allows for rapid installation and testing of OTA
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Building ODI
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QUOTA and ODI
ODI (2005) 32K x 32K Array -- Uses 64 OTAs
QUOTA (2004) “Quad Orthogonal Transfer Array” –
8K x 8K prototype to test new CCDs, controllers, software
Uses 4 OTAs – each is 4Kx4K
16”
Diagonal ~22.5 inches; Corrector ~26 inches diam
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Detector Development Status Foundry run started in Jan 2004; all wafers received in August Divided lot into 3 silicon groups to guard against flaws
8 wafers of ~30 -cm material (thin to ~15 m) 8 wafers of ~150 -cm material (thin to ~23 m) 8 wafers of ~5000 -cm material (thin to ~45 m)
Under evaluation, revealing problems in logic: Logic not switching cleanly – current leakage is occurring.
(Similar problems with MIT/LL devices, too) Good news
The “going-in” worry (4-phase design for OT) was non-issue! We have only OTCCDs outside of Lincoln!
Lincoln/PanSTARRS test devices work – revolutionary concept of an OTA has been proven.
Yields are ~70% (before thinning and packaging) J. Tonry has offered to explore running our CCDs
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STA/Dalsa 6-inch Wafers
2600x4000 pixels 12 microns
Great for spectroscopy applications
2X USNO CCDs 1Kx2K
800x1200 pixels
2 OTAs, STA LogicDesign
1 OTA, Lincoln Logic Design
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Expected Device Properties
Pixel rates > 0.7 Mpix/s (readout of array in 3 seconds) Read noise 6-8 e- (degraded by long video lines on chip) Pixel size is 12 m; MITLL also running 10 m pixels Thinning depends on resistivity (thus, so does QE, MTF vs ) Blooming is different than usual CCD with channel stops –
“puddling” of charge instead of trails is cosmetically cleaner
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QUOTA and ODI Timelines
Ramp-up of personnel (mechanical engineering, programmers): now
Conceptual Design Review (CoDR) for ODI: Dec 16-17 QUOTA purchases (dewar, filters, shutter, CryoTiger):
March 2005 Second foundry run completes: April 2005 ODI PDR: Sept 2005 QUOTA integration: Dec 2005 QUOTA commissioning: Mar 2006 ODI details available, but commissioning: mid-2008
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Conceptual Design Review
In October 2003, Board asked for CoDR within a year
Filters
Shutter
Dewar
Corrector Element #1
ADC + Corr Element #2
Dewar & Window (Corr Element #3)
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ODI Optical System
Basic design is complete, toleranced, and mechanically analyzed
Element 1
Element 2
Element 3
Fused Silica
ADC: fused silica + LLF6HT
Filter
Focal Plane
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Deflection Of Dewar WindowUnder 6000 Lbs of Atmospheric Force
.0028” (71 microns) deflection at center
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Detector Development - Demonstration
Example of an image using an MIT/LL OTA showing the controller board at Hawaii. Image provided by John Tonry. Concept of OTA is demonstrated.
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Detectors: Next Steps
Package thick OTA Continue testing and evaluation at Hawaii and WIYN If usable at all, test single OTA on telescope (0.9m) Begin Phase II of CCD contract – for a half-lot of wafers
with design revisions (12 wafers 36 OTAs) Plan minimum changes that yield science-grade OTAs Estimated cost $100K Estimated turnaround is 3-4 months
We have 8 promising 2600 x 4000 pixel CCDs for Bench, Future Echelle, KPNO, IU, SALT – cost recovery possible
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WIYN in 5 Years
Hydra on Fixed Port ODI on other Fixed Port Cass Port (in service for 2 years)
Yale dual-beam slit spectrograph (in commissioning) Densepak Sparsepak?
New Port (“folded cass”) WHIRC on WTTM Densepak? Small university instruments