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Characterization of OCam and CCD220, the fastest and most sensitive camera to date for AO wavefront sensiNG---Philippe Feautrier, Jean-Luc Gach, Philippe Balard, Christian Guillaume, Mark Downing, Norbert Hubin, Eric Stadler, Yves Magnard, Michael Skegg, Mark Robbins, Sandy Denney, Wolfgang Suske, Paul Jorden, Patrick Wheeler, Peter Pool, Ray Bell, David Burt, Ian Davies, Javier Reyes, Manfred Meyer, Dietrich Baade, Markus Kasper, Robin Arsenault, Thierry Fusco and José Javier Diaz Garcia philippe.feautrier@obs.ujf-grenoble.fr P. Feautrier - OCam and CCD220
EMCCD: Electron Multiplying CCD F: excess noise factor F = 1.4 M: mean gain P. Feautrier - OCam and CCD220
White-Yellow GS Red GS Strehl ratio Strehl ratio EMCCD RON=0 EMCCD RON=0 Thick CCD RON=2 Thick CCD RON=3 RON=2 RON=5 RON=3 RON=5 GS Magnitude. GS Magnitude. EMCCD low read noise wins • Low read noise of EMCCD is clearly better for white-yellow guide star • and better even for red GS if RON of Thick CCD > 2e. • Conclusion low RON (~ 0.1e-) is better than higher red response. • Reason e2v-EMCCD was chosen. P. Feautrier - OCam and CCD220
The e2v CCD220 EMCCD • 240 x 240 pixels with 24 µm pitch • 8 EMCCD outputs split frame transfer • Nominal frame rate: 1500 frames/sec • Peltiercooled @ - 45 °C P. Feautrier - OCam and CCD220
Ocam and CCD220 P. Feautrier - OCam and CCD220
System gain e/adu calibration System Gain = Reset current/ frame rate/charge of e = 20 adu/e Multiplication x1 Use of reset drain (per frame) current measurement embedded in OCam P. Feautrier - OCam and CCD220
0.32e 1300 fps Noise Histogram P. Feautrier - OCam and CCD220
CCD220 Quantum Efficiency Peak 94% at 650 nm P. Feautrier - OCam and CCD220
Measurement of Dark and multiplication gain G Statisticsfrom 1000 dark images Sdark : dark signal T : threshold G : multiplication gain N : fraction of pixels above T P. Feautrier - OCam and CCD220
Standard Si CCD220 Temperature: -40°C Frame rate: 1300 fps Gain, dark, noise 0 1 2 3 7 6 5 4 P. Feautrier - OCam and CCD220
Ocam technology in Europe ESO WFS camera basedon the Ocamtechnology. OCam2: WFS camera for Grantecan Delivery of 2 systemsNov 2010 P. Feautrier - OCam and CCD220
OCam2 is the commercial version of Ocam I • Improved reliability • Improved performances • Improved environmental conditions (can work with air and water temperature up to 40°C) • Detector safety (over-illumination) • More compact for integration on telescope OCam I P. Feautrier - OCam and CCD220
Other applications for OCam2 Civil aviation DROP DROP = OCAM + TELESCOPE + ROBOT + Image Analysis Runway survey from control tower at 2-3 km Avoid again Concorde crash… P. Feautrier - OCam and CCD220
Performances summarry P. Feautrier - OCam and CCD220
Exhibition Booth 306 www.firstlight.fr P. Feautrier - OCam and CCD220