FLITECAM: The first light camera for SOFIA Amanda Mainzer, I. S. McLean, T. Aliado, E. E. Becklin, G. Brims, J. Goulter, E. Kress, N. Magnone, J. Milburn, G. Skulason, M. Spencer UCLA SPIE 27 August 2002

AKM 2 SPIE 27 Aug FLITECAM Team Dr. Ian McLean, Principal Investigator Amanda Mainzer, Instrument Scientist Ted Aliado, Mechanical/Fabrication Dr. Eric Becklin, SOFIA Project Scientist George Brims, Systems Engineering John Goulter, Mechanical/Regulatory Evan Kress, Mechanical Nick Magnone, Mechanical/Fabrication John Milburn, Software Gunnar Skulason, Electronics Michael Spencer, Electronics UCLA:

AKM 3 SPIE 27 Aug FLITECAM Summary First Light Test/Experiment CAMera/ for SOFIA Features: –1- 5 µm with InSb 1024 x 1024 array –FOV: 8´ diameter (inscribed on detector) –Scale: 0.47´´ per pixel –LHe/LN 2 system –Grism Spectroscopy (R~2000) –Co-mounts with HIPO First light: ~Q (ground based) Delivery to SOFIA: Q Must be fully FAA certified Y(side) X(aft) Z(up)

AKM 4 SPIE 27 Aug FLITECAM’s Field of View Originally going to use 512x512 array Between PDR and CDR, switched to 1024x1024 array to image the entire 8 arcmin SOFIA field of view

AKM 5 SPIE 27 Aug Optics Modes: - Imaging - Grism (R~2000) - Pupil viewing Optical design: - Collimator triplet - F/5 imaging camera - 4 fold mirrors - Dual filter wheel - 3 pupil viewing lenses - Filters: ZJHKK’LM + selected narrow band

AKM 6 SPIE 27 Aug Image Quality SOFIA seeing ~2-3 arcsec FLITECAM PSF: arcsec across entire 8 arcmin field of view FLITECAM designed to fully evaluate SOFIA image quality Box = 2x2 pixels 1 pixel = 0.47 arcsec

AKM 7 SPIE 27 Aug Thermomechanical Optical Design Large crystal lenses have to be cooled in controlled fashion to avoid thermomechanical shock Collimator: LiF, BaF 2, ZnS all with diameter ~165 mm Spring-loaded “finger” mounts isolate lenses and prevent thermomechanical shock Lenses manufactured by Brad Picirillo of Optical Solutions Inc. of New Hampshire LiF lens Spring-loaded “fingers”

AKM 8 SPIE 27 Aug Thermomechanical Performance Large LiF and BaF2 lenses particularly susceptible to thermal & mechanical shock Spares difficult & expensive to obtain - 9 month lead time! To verify success of our mounting/thermal isolation scheme, we constructed a dummy collimator

AKM 9 SPIE 27 Aug Dummy Collimator 77 K end Thermometers: front center, front edge, back edge LiF spare lens Glass blanks ~165 mm Brad Picirillo of OSI provided spare unpolished LiF lens for dummy collimator Put in two additional glass blanks to simulate thermal characteristics of BaF 2 and ZnS lenses Epoxied thermometers to spare LiF: front/back center, and front edge Additional thermometers on collimator housing and optical baseplate This allowed us to monitor gradients vs. cooldown rate

AKM 10 SPIE 27 Aug Thermomechanical Optical Design cont’d. Cooldown rates controlled by isolating selected components with G10 Time constants calculated and measured to determine safe rates Thanks to Brad Picirillo of OSI for providing spare LiF! Will eventually test spare LiF to destruction Results show that cooldown rates of up to 13 K/hr are safe! Edge to center gradient Front center to back center gradient

AKM 11 SPIE 27 Aug Warm First Light To avoid long iterative cryogenic cycles, found focus warm Confirmed warm focus with warm Zemax optical model Warm best focus location agreed with warm focus model to within depth of focus Set focus to predicted cold focus location

AKM 12 SPIE 27 Aug Completed Software Java  platform- independent Software controls temperature sensors, vacuum gauge, helium level sensor, detector heater, and mechanisms Astronomical Observation Requests (AORs) will be written using a modified version of SPOT (SIRTF Planning and Observation Tool)

AKM 13 SPIE 27 Aug Electronics Detector head and electronics purchased from Mauna Kea Infrared These systems are being packaged into 19” racks for ground-based operations: – Data acquisition system – Mechanism controllers – Temperature controllers – Pressure monitors – LHe level monitor – Power controller Multiplexer CW Rack SHARC Processor On-Cryostat Electronics

AKM 14 SPIE 27 Aug Cryogenics LN2/LHe cryostat manufactured by Precision Cryogenics of Indianapolis, IN 20 L of LN2, 20 L of LHe FAA regulations: cryostat can only be filled when plane is on the ground Will fill before each night’s observing Cylindrical design dictated by SOFIA volume allocation Cryostat can either look up or horizontal - can be used on ground

AKM 15 SPIE 27 Aug DAR witnessed testing at PCI on 28 March 2002 LN 2 Container Pressure Test measuring the deformation of container under pressure checking conformance with drawings FLITECAM FAA Cryogen Container Testing

AKM 16 SPIE 27 Aug FLITECAM Assembly

AKM 17 SPIE 27 Aug Milestones

AKM 18 SPIE 27 Aug Commissioning Three fall observing runs scheduled at 3-m Shane Telescope at Lick Observatory Shane telescope’s F/17 optics well-matched to SOFIA’s F/19.6 First run starts Sept. 13! Will observe a variety of star forming regions Observations will constitute part of A. Mainzer’s Ph.D. thesis