CCD Mosaics at CTIO and SOAR. Abstract: Mosaics based on 2K x 4K CCDs are briefly reviewed. An 8Kx8K mosaic of SITe002A CCDs is in use at the 4m Blanco telescope. At the SOAR 4.1 m telescope E2V CCDs are used in an 4Kx4K Imager and another 4Kx4K mini- mosaic utilizing CCID20 detectors will be employed by the Goodman Spectrograph. A 62 CCD mosaic incorporating high resistivity CCDs from LBNL is part of the Dark Energy Camera project that should be available at the 4m Blanco telescope by Each of these four types of 2K x 4K CCDs have two output amplifiers and 15 micron pixels. 4m BLANCO: 8K x 8K MOSAIC-2 (Imager). 2xCCD44-82 (E2V) 3 edge buttable, CCD44-82s have an extra FET to buffer the output stage (hence 2 drain voltages). Setting V_OD too high causes amplifier glow. This CCD has two Outputs Gates and also a Dump Drain. M83 This SOI 5x5 arcminutes color image, obtained on February 16th 2005, is composed of two sets of 0.7 arcsec FWHM images taken at the B, V and R filters. A 20 arcseconds shift was applied between the two sets of observations in order to eliminate the central gap of the CCDs mosaic in the final image. SOAR IMAGER: 4k x 4k Mini-Mosaic of E2V CCDs A Mini-Mosaic made of two CCD44-82 detectors covers a 5.5 x 5.5 arcmin FOV at 0.08” / pix on the SOAR 4.1m telescope. It includes twin filter wheels -5 positions ea.- and a fast linear shutter. This Imager started operations in MOSAIC-2SOAR IMAGERGOODMAN SPECT.DECAM 8 three-side buttable SITe002A CCDs are used by Mosaic-2 to cover a FOV of 36’ x 36’, at a scale of 0.27”/ pix. Its shutter and a 14-filter track –running in a loop over the dewar top- are both pneumatically actuated. This wide field Mosaic Imager has been in regular use for the past 6 years at the 4m Blanco telescope and is typically scheduled 120 nights per year. Mosaic-2 is a copy of KPNO’s Mosaic-1. However to read out Mosaic-2 uses 16 channels whereas Mosaic-1 uses 8 channels. One Mosaic image represents 140 MB of data. The peak QE for SITe002As is 85% at 600 nm; the CCDs run at -95 o C. Fringing is < 5% in the I band, there is some low level crosstalk which gets successfully removed, there are no after- images. Grounding: CCDs are wired to the corresponding Arcon star point -at the Arcon backplane (=multilayer planar PCB)- and are isolated from the detector mount and dewar. Ricardo E. Schmidt, CTIO / NOAO SDW2005, Taormina. Collimator Articulated Camera SOAR Goodman Spectrograph: P.I.: Chris Clemens (UNC). With Long-slit & Multi-slit capabilities it uses a 4k x 4k Mini- Mosaic and covers an effective FOV of 7.2’ diameter on SOAR, at a scale of 0.15” / pix. Observing will start in CCID20 This system is optimized for the UV/Blue. The CCID20 requires sequencing of reset and drain voltages on power up and power down: of the two, the output drain should be the last to be turned on and the first to be turned off. The CCID20 uses high resistivity bulk silicon thinned to 40 µm and hence there is an asociated red QE boost and less fringing due to larger thickness. This 3 side buttable CCD is back-illuminated but not MPP. For the CCID20 we get a lowest noise of 1.9 e- at a conversion gain of 0.4 e- / ADU. We treated the CCID20 with dry air plus heat to solve some cosmetic problems and to get an increased QE. NOAO’s Monsoon controller will be used to read out the 62 CCDs. 18 CCDs will be treated as “6 groups of 3”, with the assumption that the same clock rails can be applied to groups of 3 CCDs. o T CCD will be read for each CCD and used for QE corrections. Dark Energy Camera, a collaboration -lead by Fermilab- to build a 62 CCD Imager. DECAM will be used for a 5000 sq. deg. survey to constrain the Dark Energy parameter w to ~ 5%. DECAM observing to start in LBNL high resistivity, n-type silicon CCD which can be fully depleted. Clock and bias voltages are reversed in sign from conventional CCDs. This 4 side buttable, back illuminated CCD has a QE> 50% at 1000 nm. These CCDs: 1) Use a buried p-channel 2) Use substrate bias voltage to fully deplete substrate and control PSF 3) Require special erase procedure The CCDs will be packaged by Fermilab. A scroll shutter design is being tested. Frontend electronics Feed through bd. The DECAM instrument will replace the Blanco 4m Prime Focus Cage DewarShielded cableSDSU-2 ctrlr. Heat exchanger 8K x 8K Mosaic Dewar and four ARCONs shown Controller 62 CCD Imager, FOV = 2.2 deg diam and active area diameter = ”/pix on 4m Blanco PF. 2 x CCID20 Cryotiger DECAM on 4m BLANCO A LabVIEW based GUI called ArcVIEW is used with this Imager. ArcVIEW uses a Client / Server scheme and runs in a Linux environment on a PC. An image binned 4x4 is read out in 6 sec RON of 3.8 e). 2Kx4K One Arcon At the telescope images show fringing of < 2% in the I band. No after- images are seen. 2K x 4K CCDs with 15 micron pixels8 x SITe 002A2 x E2V CCD x MIT/LL CCID2062 x LBNL 2Kx4K CCD technology (all w. 2 output amps) Thinned, n-channel Hi Rho (40 µm), n-chan. Hi Rho (250 µm), p-chan. Controller4 x ARCONSDSU-2 4 x MONSOON Video boards 4 channel 2 channel ea. 12 channel ea. Controller – Dewar connection Direct (connector–connector) 0.5m cable1.2m cable Electronics inside dewarNone t.b.d. Shared signals LG A/B,H+SW rails per 1/2H-reg RG L/R, DD/RD L per H-regRG per H-reg, P U/L per CCD Clock rails per 3 CCDs Detector coolingRadiative/conductive, LN2LN2Cryotiger Detector issues Slow parallels => long readout PSF = f (V_backside_bias =< 80V) Output amp glow for high V_OD Treat to improve QE and cosmetics Cryocooler Controller cooling PassiveLiquid coolant Liquid coolant (rack) Chip mount material; heater Invar; embedded pwr-Rs Al ; emb. Nickel-Chromium wire Invar; 8x FETs on PCBInvar; pwr-Rs Wiring inside dewar Constantan & Cu wires Wires (Constantan&Cu), flex Constantan & Cu wiresflex Times (dwell, pixel, readout) for bin 1x13.6 µs, 14 µs, 100s1 µs, 3.7 µs, 20 s 1 µs, 4 µs, 20s CCD responsivity, RON 1.8 µV/e, e/ADU 5 µV/e, e/ADU10 µV/e, 2 e/ADU3 µV/e, <10e Typical biases: V_OD, V_RD, V_OG 25 V, 14.3 V, 2 V (V JD =26V) 23.2V,10V,-4.7V OG1 & -3.7V OG V, 12.7 V, -1 V-22 V, V, 2.2 V 0.7m cable DEWAR FOR GOODMAN