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
FLITECAM Team
UCLA:
• 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
AKM 2
SPIE 27 Aug. 2002
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/LN2 system
– Grism Spectroscopy (R~2000)
– Co-mounts with HIPO
• First light: ~Q3 2002
(ground based)
• Delivery to SOFIA: Q1 2004
• Must be fully FAA certified
AKM 3
Z(up)
Y(side)
X(aft)
SPIE 27 Aug. 2002
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 4
SPIE 27 Aug. 2002
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 5
SPIE 27 Aug. 2002
Image Quality
• SOFIA seeing ~2-3 arcsec
• FLITECAM PSF:
0.2 - 0.5 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 6
SPIE 27 Aug. 2002
Thermomechanical
Optical Design
• Large crystal lenses have to be cooled
in controlled fashion to avoid
thermomechanical shock
• Collimator: LiF, BaF2, 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 7
SPIE 27 Aug. 2002
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 8
SPIE 27 Aug. 2002
Dummy Collimator
•Brad Picirillo of OSI provided spare
unpolished LiF lens for dummy
collimator
77 K end
~165 mm • Put in two additional glass blanks to
simulate thermal characteristics of
BaF2 and ZnS lenses
• Epoxied thermometers to spare LiF:
front/back center, and front edge
Thermometers: front center,
front edge, back edge
Glass blanks
LiF spare lens
• Additional thermometers on
collimator housing and optical
baseplate
• This allowed us to monitor gradients
vs. cooldown rate
AKM 9
SPIE 27 Aug. 2002
Thermomechanical
Optical Design cont’d.
LiF Lens Gradients vs. Temperature
Temperature Differential (K)
2
• Cooldown rates controlled by
isolating selected components with
G10
1.5
1
0.5
• Time constants calculated and
measured to determine safe rates
0
300
250
200
;
150
100
50
-0.5
-1
-1.5
-2
Temperature (K)
Edge to center gradient
Front center to back center gradient
AKM 10
• 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!
SPIE 27 Aug. 2002
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 11
SPIE 27 Aug. 2002
Completed Software
• Java platformindependent
• 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 12
SPIE 27 Aug. 2002
Electronics
• Detector head and electronics purchased
from Mauna Kea Infrared
On-Cryostat Electronics
• 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
AKM 13
Multiplexer
CW Rack SHARC Processor
SPIE 27 Aug. 2002
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 14
SPIE 27 Aug. 2002
FLITECAM
FAA Cryogen Container Testing
DAR witnessed testing
at PCI on 28 March 2002
LN2 Container Pressure Test
• measuring the deformation of
container under pressure
• checking conformance with
drawings
AKM 15
SPIE 27 Aug. 2002
FLITECAM Assembly
AKM 16
SPIE 27 Aug. 2002
Milestones
CY 01
CY 02
1 2 3 4 5 6 7 8 9 101112 1 2 3 4 5 6 7
Fwd
Top Level SOFIA Milestones
Bulkhead
FY01>
Complete
CY 03
FLITECAM Del’y FLITECAM
to SSMOC 3/30/04 Acceptance 10/1/04
Integration
and test
FLITECAM Cryostat
8110-3 20/9/01
Cryostat
CY 04
8 9 101112 1 2 3 4 5 6 7 8 9 101112 1 2 3 4 5 6 7 8 9 101112
Aircraft
TA Ground OFR
Obs. Flt. Perf. Flight
ORR
Structures mod.
Acceptance Review
Test Done Test
9/28
Complete
Test &Review
Integration
and test
Electronics
Optics
Alignment and test
System Level Tests
Software Development
First Light
in Lab?
Integration
and test
Ongoing Software development and Validation
FLITECAM/HIPO INTEGRATION
IT & V
Phase
Telescope
Deployment
Aug 02
FLITECAM/HIPO Deployment
to JAITV Jun 03
1 2 3 4 5 6 7 8 9 101112 1 2 3 4 5 6 7 8 9 101112 1 2 3 4 5 6 7 8 9 101112 1 2 3 4 5 6 7 8 9 101112
AKM 17
SPIE 27 Aug. 2002
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
AKM 18
SPIE 27 Aug. 2002