Transcript ppt
LSST Camera Filter Status SDSS Band-pass Transition Half Maximum Transmission Wavelength (nm) g r i z Blue side 402 552 693 840 Red side 548 693 851 LSST Band-pass Transition Half Maximum Transmission Wavelength (nm) u g r i z y1 y2 y3 Blue side 330 400 552 691 818 960 970 970 Red side 400 552 691 818 922 1030 1020 1050 G-Balmer break @400. OI line@ 557 R-matches SDSS I-red side short of sky emission @826 Z-red side stop before H2O bands Y–options detailed Optical Design: Filter Reference Design Filter band-pass characteristics are defined based on a combination of scientific considerations U G R I Z Y • 75 cm dia. • Curved surface • Filter is concentric about the chief ray so that all portions of the filter see the same angle of incidence range, 14.2º to 23.6º Half-Maximum Transmission Wavelength Red Comments Side 400 Blue side cut-off depends on AR coating 552 Balmer break at 400 nm 691 Matches SDSS 818 Red side short of sky emission at 826 nm 922 Red side stop before H 2O bands 1070 Red cut-off before detector cut-off Blue Side 330 400 552 691 818 930 LSST Ideal Filters 100.0 80.0 Transmission * Uniform deposition required at 1% level over entire filter 60.0 u g r i z Y 40.0 20.0 0.0 300 400 500 600 700 800 Wavelength (nm) 900 1000 1100 1200 LSST Filter Set LSST Ideal Filters 100.0 Transmission 80.0 60.0 40.0 u g r i z Y 20.0 0.0 300 400 500 600 700 800 Wavelength (nm) 900 1000 1100 1200 Filter prototype RFP going out to vendors * * * Discussions initiated with multiple vendors – JDS Uniphase – Infinite Optics – SAGEM – Barr – Goodrich – Asahi Spectra 300cm coating chamber Substantial industrial base exists to coat large, thin filters Industry estimates of cost and schedule to coat these large, thin optics have been used as input for LSST camera optics schedule and budget – These estimates include a risk reduction study during the R&D phase NOVA Laser Fusion Optics Leak Update QuickTime™ and a decompressor are needed to see this picture. QuickTime™ and a decompressor are needed to see this picture. Orig Design Updated Design Y-Band Options (Y2, Y3 and Y4) QuickTime™ and a decompressor are needed to see this picture.