[90.03] Status of the HST Wide Field Camera 3
J.W. MacKenty (STScI), R.A. Kimble (NASA/GSFC), WFC3 Team
The Wide Field Camera 3 is under construction for a planned
deployment in the Hubble Space Telescope during Servicing Mission 4.
In early 2005, WFC3 will replace the aging WFPC2 instrument in the
HST radial bay.
WFC3 provides two imaging channels. The UVIS channel features a
4096 x 4096 pixel CCD focal plane with sensitivity from 200 to 1000 nm.
Equipped with 47 filters and an ultraviolet grism, the UVIS channel
provides unprecedented sensitivity and field of view in the near
ultraviolet for HST. The IR channel features a 1014 x 1014 pixel
HgCdTe focal plane covering 850 to 1700 nm. With 17 filters and 2
grisms, this provides HST with a powerful near infrared capability.
Science Oversight Committee
SOC Member
Bruce Balick
Howard Bond
Daniela Calzetti
Marcella Carollo
Michael Disney
Michael Dopita
Jay Frogel*
Donald Hall
Jon Holtzman
Gerard Luppino
Patrick McCarthy
Robert O’Connell (Chair)
)Francesco Paresce
Abhijit Saha
Joseph Silk
John Trauger
Alistair Walker
Brad Whitmore
Rogier Windhorst
Erick Young
Affiliation
University of Washington
Space Telescope Science Institute
Space Telescope Science Institute
Columbia University
University of Wales At Cardiff
Institute of Advanced Studies
Mt. Stromlo & Siding Spring Observatory
Ohio State University (now NASA HQ)
University of Hawaii
New Mexico State University
University Of Hawaii
Carnegie Observatories
University of Virginia
European Southern Observatory
National Optical Astronomy Observatory
University of California, Berkeley
Jet Propulsion Laboratory
NOAO CTIO
Space Telescope Science Institute
Arizona State University
University of Arizona
• WFC3 is a facility instrument being developed on
behalf of HST user community
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–
–
–
Will replace WFPC2 in Hubble during SM4 (February 2005)
Assures excellent HST imaging science to end of mission
International Scientific Oversight Committee (SOC)
Integrated Product Team: GSFC, STScI, Ball Aerospace, …
• Randy Kimble (GSFC) Instrument Scientist [replaced Ed Cheng
9/02]
• John MacKenty (STScI) Deputy Instrument Scientist
• WFC3 a “panchromatic” camera for HST
– Two channels cover Near-UV to Near-IR
– UVIS CCD channel backs up ACS from 200 to 1000 nm
• Provides powerful new wide field imaging from 200 to 400 nm
– NIR HgCdTe channel extends NICMOS Infrared capabilities
• 10242 detector offers 7x NICMOS FOV from 850 to 1700 nm
WFC3
UVIS
WFC3
IR
SOFA
UVIS
Shutter
UVIS
Detector
UVM1 &
Corrector
Mechanism
Calibration
Subsystem
UVM2
IRM1
IR Cold
Enclosure/
RCP/Filters/
Detector
IR Fold
Mirror
IRM2 &
Corrector
Mechanism
Pickoff Mirror
Channel Select
Mechanism
Detector Heat Pipes
Not Shown - WFC3 will reuse the
EVA Radiator Handhold, Stowage
Fixture and POM cover.
Radiator Truss
Assembly
LVPS
MEB #2
Electronics
Radiator
DEB (under MEB)
Main (Detector)
Radiator w/
Light Baffle
Blind Mate Connector
Optical Bench
MEB #1
Mechanism
Cover
CEB
WF/PC I H/W reuse
HST Heritage
New H/W
C-Latch
Enclosure
A-Latch
Pick-Off
Mirror
Re-flight of WF/PC-1 Hardware
UVIS Filter Assembly
External Enclosure
Thermal Radiator
1
0.9
WFC3 Wide UV Filters
0.8
Transmission
0.7
0.6
0.5
0.4
UVIS 03
(F275W)
F218W
UVIS 15
(F300X)
0.3
F225W
0.2
F275W
F300X
0.1
0
1500
2000
2500
3000
Wavelength (A)
3500
4000
4500
Optical Alignment and
Characterization Complete
Meets or Exceed Requirements
Flight IR Filter Wheel
F164N
Blank
F160W
F125W
F167N
G141
F126N
F110W
F132N
F105W
F130N
F098W
F128N
G102
F127M
F139M
F093M
F153M
STATUS
WFC3 in Integration and
Test Phase at GSFC
Optical Assembly delivered
by Ball Aerospace Dec 02
w/ Electronics and Software
Optical Alignment complete
UVIS Detectors in testing
IR Detectors in fabrication
On schedule for Fall 03
final System Level tests
Optical Bench
IR Cold enclosure
With Filter Wheel
Main Computer under Test at Ball Aerospace
UVIS Channel
•
•
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•
Focal Plane Array:
FOV:
Wavelength Range:
Spectral Components:
Two 2K x 4K E2V (Marconi) CCDs
162 x 160 arcsec (39 mas pixels)
200-1000nm
42 filters, 5 quad filters, and 1 UV grism
Quantum Efficiency
Flight Build 1 CCDs QE
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
180
380
580
780
980
Wavelength (nm)
CCD Detectors have 2.1 to 2.5 e- readnoise (3-3.5 e- w/ electronics)
Excellent initial Charge Transfer Efficiency
Provision for low noise (10-15 e- rms) Charge Injection
mitigates nearly all radiation induced charge transfer loss
IR Channel
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•
•
•
Focal Plane Array:
FOV:
Wavelength Range:
Spectral Components:
1K x 1K Rockwell HgCdTe Hawaii-1R
123 x 139 arcsec (120 x 130 mas pixels)
850-1700nm
15 filters and 2 grisms
Mounted on 6 stage TEC
Similar to CCD operation
Does not require cryogen
MUX has 5 rows of reference
pixels on each edge to
provide zero level tracking
Quantum Efficiency
IR Detector #64
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
750.00
950.00
1150.00
1350.00
1550.00
1750.00
Wavelength (nm)
1300 nm flat field
IR Detector Status
Tuned long wavelength cutoff at 1.73 microns (150K operation)
Dark Current better than specification (0.1 to 0.2 e-/s/pix)
Past difficulties with stability appear fixed in most recent lot
Readnoise of 21-23 e- (correlated double sample)
Exceeds specification of 15 e- but much improved
Operability and uniformity excellent