Transcript ppt
LSST Camera Detector Status Sensor development on the schedule critical path – – – – – – – High QE to 1000nm • Thick silicon - 100µm thick and BB AR coating PSF << 0.7” (0.2”) • High resistivity substrate (> 5 kohm∙cm) • Small pixel size (0.2” = 10 µm) Fast f/1.2 focal ratio • Sensor flatness < 5µm p-v • Package with piston, tip, tilt adj. to ~1µm Wide FOV • ~ 3200 cm2 focal plane • > 189 Science-sensor mosaic High throughput • > 90% fill factor • 4-side buttable package, sub-mm gaps Fast readout (1 s) • Segmented sensors - ~3200 total output ports • 150 I/O connections per sensor Low read noise • < ~ 5 rms electrons R&D Program • Funding secured by Keck Foundation to keep development moving. • Three phase development - Study phase sensor evaluation begun at BNL • Prototype phase: Contracts with two vendors signed Multi-port 4K x 4K = 16M Pixel CCD Detail of output port Detail of one edge July 7, 2008 J. Geary, “LSST Strawman CCD Design”, Dec. 2004 SLAC Annual Program Review 3 Sensor development plan • Technology study – – – – • Prototype – – – – • understand and model device characteristics engage qualified vendors address the most pressing technical challenges early establish test lab at BNL multivendor competition fabricate sensor meeting all LSST specifications demonstrate yield and quality control ramp up test capability within LSST collaborating institutions Production – – – manufacture, test, and deliver 200+ science-grade sensors 24-month production period single- or dual-source 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 Modeling and trade studies Technology Study 3 Vendors Prototypes 2 Vendors DOE MIE Funding Sensor procurement starts July 7, 2008 4 BNL and sensor group are providing leadship for schedule driven sensor development • Request for proposals for prototype science CCDs – issued Feb. 2008 – contract award June/July 2008 • 5 high-resistivity, thick CCDs from study program have been extensively characterized – design models validated – behavior of dark current, quantum efficiency, and point spread function vs. thickness, temperature, and electric field – flatness and surface morphology – antireflection coating -50V • CCD controllers for 4 new test labs under construction – UC Davis, SLAC, Paris, Purdue – allows full-speed testing of segmented sensors • Components for CCD/electronics chain testing in assembly X-ray images -10V