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Key R&D Activities for the LSST Camera
DOE HEP Program ReviewJune 13, 2007
Kirk Gilmore (SLAC)
LSST Camera Manager
2
BrandeisJ. Bensiger, K. Hashemi, H. WellensteinBrookhaven National LabS. Aronson, C. Buttehorn, J. Frank, J. Haggerty, P. Kuczewski, M. May, P. O’Connor, V. Radeka, P. TakacsFlorida StateH. WahlHarvard UniversityN. Felt, J. Geary (CfA), J. Oliver, C. StubbsLawrence Livermore National LabS. Asztalos, K. Baker, L. Hale, S. Olivier, D. Phillion, L. Seppala, W. Wistler
Oak Ridge National Laboratory P. Stankus, G. Young, V. Cianciolo,
C. Britton (joint faculty UT) N. Ericson (joint faculty UT)Ohio State UniversityK. Honscheid, R. Hughes, B. WinerPurdueI. Shipsey, J. PetersonRochester Institute of TechnologyD. Figer
Stanford Linear Accelerator CenterG. Bowden, P. Burchat (Stanford), D. Burke, M. Foss, K. Gilmore, G. Guiffre, M. Huffer, S. Kahn (Stanford), P. Kim, T. Lavine, S. Marshall, M. Nordby, M. Perl, L. Price, A. Rasmussen, D. Rich, R. Schindler, L. Simms (Stanford), T. Weber
University of California, Berkeley
J.G. Jernigan
University of California, Davis
P. Gee, A. Tyson
University of California, Irvine
D. Kirkby
University of California, Santa Cruz
T. Schalk
University of Illinois, Urbana-Champaign
J. Thaler
University of Pennsylvania
M. Newcomer, R. Van Berg
University of Washington
L. Rosenberg
University of Tennessee
B. Blalock, R. Chun
Wayne State
D. Cinabro
LSST Camera Team Members
DoE HEP Program ReviewJune 13, 2007 3
Camera R&D Overview• Detector requirements: Detector requirements: ((Radeka/Geary - BNL/SAO))
– 10 10 m pixel size Pixel full-well > 90,000 em pixel size Pixel full-well > 90,000 e– – High QE 400 – 1000 nm High QE 400 – 1000 nm– Low noise (< 5 eLow noise (< 5 e–– rms), fast (< 2 sec) readout, stable T (-90 C) rms), fast (< 2 sec) readout, stable T (-90 C)
• Package large number of detectors, with integrated readout electronics, Package large number of detectors, with integrated readout electronics, with high fill factor and serviceable design with high fill factor and serviceable design (O’Connor/Oliver - BNL/Harvard)
• Sensor and focal plane precision alignment/stabilility/motion controlSensor and focal plane precision alignment/stabilility/motion control Sensor flatness 5u p-v, focal plane flatness 10u p-v Sensor flatness 5u p-v, focal plane flatness 10u p-v ((Takacs/Rasmussen/Schindler - BNL/SLAC/SLAC))
• Cryostat contamination control -Cryostat contamination control - (Schindler - SLAC)(Schindler - SLAC)
• Fabricate large diameter (75cm) filters with uniform coatings Fabricate large diameter (75cm) filters with uniform coatings ((Olivier - LLNL))
• Data Acquisition/ Camera Control ProtocolData Acquisition/ Camera Control Protocol - - ( (Schalk - UCSC))
• Constrained volume (camera in beam) Constrained volume (camera in beam) ((Nordby - SLAC))–Makes shutter, filter exchange mechanisms challengingMakes shutter, filter exchange mechanisms challenging
4
Camera: International R&D ContributionsFilter mechanism:M. Nordby (SLAC)The LPNHE team is taking responsibility of studying and prototyping ... P. Antilogus (LPNHE) will act as contact scientist and G. Daubard (LPNHE) as technical contact.
Shutter Development:M. Nordby (SLAC)Bonn Group is studying Gordon Bowden (SLAC) design. Dialog between Bonn and SLAC started.Klaus Reif of the University of Bonn is main contact and head of shutter group
Filter development:K. Gilmore (SLAC)LSST is currently looking for qualified vendors to evaluate filters.R. Pain (LPNHE) and the LPNHE/Lyon teams will help coordinate SAGEM evaluation
Analog signal processing ASIC:J. Oliver (Harvard)A joint LAL+LPNHE team will take responsibility of prototyping the FE ASIC.P. Antilogus (LPNHE) will act as contact scientist and V. Tocut (LAL) as technical contact.
Software slow control:T. Schalk (SLAC/UCSC)The IN2P3 groups will evaluate a possible contribution in the control software and hardware of the camera. P. Antilogus (LPNHE) will act as contact for this effort.
Instrumental calibration:D. Burke (SLAC):The LPNHE group will participate in the definition of an instrumental calibration strategy for LSST.P. Astier (LPNHE) will act as contact scientist for this effort.
DoE HEP Program ReviewJune 13, 2007 5
Sensor Fabrication and Delivery Schedule_______________________________________________
• Contracts with four vendors for study phase • Goals:
– technology development leading to back-illuminated sensors with thick, fully depleted substrate and transparent conductive window– large-format, small pixels Schedule– flat, 4-side-buttable package 1. Study - Jan06-Feb07 2. Prototype - Jul07-Aug09 3. Production - Oct09-Sep12
Risks
1. CCD performance2. Mulit-port R.O.3. Flatness4. Packaging
DoE HEP Program ReviewJune 13, 2007 6
Shutter Reliability_______________________________________________
- Required cycle life is long- Belt-drive system could behave
differently depending on orientation- Blade dynamics could be an issue at
high-speed- Wear and near-constant motion could
produce particulates that wouldcontaminate L3 lens and filters
Shutter Assembly Closed
Motors with 3 drive pulleys of different diameters
Shutter Assembly Open
Drive rail contains ball-roller track with 6 carriages for each of the blades
Blades are contoured to fit around convex crown of L3 to save Z-space
Blades stack beyond field of view when not in use
Guide rail channel tracks cam followers in blades to reduce sagging of blades
DoE HEP Program ReviewJune 13, 2007 7
Filter Fabrication_______________________________________________
R&D: Coating of large filters requires large coating facilities with precision process controls to meet LSST filter coating specs.
0.0
20.0
40.0
60.0
80.0
100.0
300 400 500 600 700 800 900 1000 1100 1200
Wavelength (nm)
Tra
nsm
issi
on
u g r i z Y
DoE HEP Program ReviewJune 13, 2007 8
Electronics Packaging in a Constrained Volume
_______________________________________________
The Raft-Tower is comprised of sensors, structures requiring precise alignment, and high-density front-end electronics boards.
Raft TowerRaft TowerFront-side
View
FEE Boards
Raft
Flex cables and Thermal Straps
Front-end ASIC
DoE HEP Program ReviewJune 13, 2007 9
DAQ/CCS Communications Protocol R&D
• Determine functionality of controls and data acquisition
• Prototype test stand to establishcommunication configuration
• Prototype system to facilitate sensor and raft development
OCS
SAS SDS FCS
DM
MCM
DAQ Client interface
Subsystem modules
Control interface
CCS
Controls Architecture
Controls Reference Design Subsystems
Science Array (SAS)Data Acquisition (SDS)Wavefront Sensor (WFS)Wavefront Data Acquisition (WDS)Guide Sensor (GSS)Guide Sensor Data Acquisition, Analysis (GAS)Focal Plane Actuation Unit (FPU)Shutter Controller Unit (SCU)Filter Controller (FCS)Thermal Control (THC)Vacuum Control (VCS)Power and Signal Controller Unit (PSU)
DoE HEP Program ReviewJune 13, 2007 10
Filter Exchange Mechanism R&D
Prototype Questions• Five filters just fit in the
camera• Double-rail mechanism
could bind in operation• Clamps and locking pins
could fail
Filter Changer and Carousel Assemblies
Rails and ball screw provide linear actuationYoke
Linkage converts linear actuation to follow filter path
Double-rail provides X, Z, and tilt motion of filter
Filter clamp into base cradles
Carousel ring bearing mounts to back flange
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