WFC3
Ambient Calibration #2 Results
H. Bushouse
TIPS May 17, 2007
1
Ambient Cal #2 Overview
• WFC3 ambient calibration #2 ran from April 13-19, 2007
– WFC3 in the GSFC SSDIF clean room
– Latched into Radial Instrument Alignment Fixture (RIAF) and
“CASTLE” optical stimulus
– UVIS channel operations only (IR can’t be cooled sufficiently in
ambient)
– UVIS-2 detector with CCD’s at -54 C (vs. -83 C flight temp)
• Goals:
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Verify re-integrated instrument operations
Verify successful lien closures
First look at UVIS-2 in (nearly) flight-like conditions
Verify operations of ground support equipment to be used in thermalvac #2
– Train and verify operations of support personnel
TIPS May 17, 2007
2
Instrument Preparations for
Ambient Cal #2
WFC3 closeout just prior to top cover installation
WFC3 top cover installed
WFC3 lift from Low Level Positioner (LLP)
WFC3 inserted into Radial Instrument
Alignment Fixture (RIAF)
TIPS May 17, 2007
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Accomplishments
• ~30 SMSs, ~110 hours, 1525 images
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Optical stimulus verification
UVIS-2 detector alignment check
System throughput with UVIS-2
Filter ghost check (lien related)
CCD electronic crosstalk check (lien related)
UVIS grism calibration: throughput, dispersion, and flat fields
Internal Calibration Subsystem check (lien related)
UVIS-2 bias, dark, readnoise, gain measurements
UV flats signal level check
Encircled energy check
CCD charge injection test
First test of CCD Extended Pixel Edge Response (EPER) mode
• Excellent job by I&T, Ops, CASTLE & Sci Cal teams
TIPS May 17, 2007
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Thanks are due …
• IS’s
– S. Baggett, T. Brown, H. Bushouse, G. Hartig, A.
Martel, L. Petro, M. Robberto
• DA’s
– E. Barker, M. Cracraft, B. Hilbert, S. Holfeltz, D.
Karakla, J. Kim, K. Lindsay, D. Long, R. Lucas, J.
Mack, H. McLaughlin, C. Pavlovsky, B. Shaw, E.
Smith, M. Sosey
TIPS May 17, 2007
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Instrument Science Reports
• ISR 2007-15: WFC3 Ambient-2 Testing: UVIS Readnoise
S. Baggett 11 May 2007
• ISR 2007-14: WFC3 Ambient-2 Testing: Calibration Subsystem Performance
S. Baggett 7 May 2007
• ISR 2007-13: UVIS CCD EPER CTE measurements
M. Robberto 30 Apr 2007
• ISR 2007-11: WFC3 Ambient-2 Testing: UVIS Gain Results
S. Baggett 27 Apr 2007
• ISR 2007-10: WFC3 Ambient Testing: UVIS Dark Current Rate
B. Hilbert 26 Apr 2007
• ISR 2007-09: UVIS Channel Filter Ghosts after Filter Replacement
T. Brown 26 Apr 2007
• ISR 2007-08: Searching for Scattered Light on the WFC3 UVIS-2 Detector
T. Brown 24 Apr 2007
• ISR 2007-07: WFC3 System Throughput on the UVIS Build 2 Detector
T. Brown 19 Apr 2007
TIPS May 17, 2007
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System Throughput with UVIS-2
From STScI
Instrument
Science Report
WFC3-2007-07
(Tom Brown)
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UVIS-2 QE better than predicted
Response of both CCDs comparable to UVIS-1 chip 1
UVIS-2 curves subject to small revision at proper operating temp
Optics throughput appears to have held up well since 2004 TV#1
TIPS May 17, 2007
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UVIS Detector Throughput
UVIS Detector
Comparison
Comparison
(UVIS-1 QE) / (UVIS-2 QE)
1.8
1.6
1.4
1.2
1
0.8
0.6
200
300
400
500
600
700
800
900
1000
Wavelength (nm)
Ratio of Higher QE CCDs
Ratio of Average QEs
• UVIS-1 wins in blue; UVIS-2 wins in red
• F225W only important filter for which response differs by >10%
TIPS May 17, 2007
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Excellent Read Noise w/ UVIS-2
• Like UVIS-1, UVIS-2 demonstrates “goal” level read
noise of 3 e- rms, vs. spec of 4; very important in UV
Gain = 1 e-/DN
UVIS-2 (ambient) UVIS-1 (ambient)
Amp A
2.95
3.02
Amp B
2.94
2.97
Amp C
2.81
2.86
Amp D
2.90
2.99
Amp A
3.35
3.21
Amp B
3.34
3.25
Amp C
3.26
3.23
Amp D
3.53
3.28
Gain = 1.5 e-/DN
S. Baggett
TIPS May 17, 2007
9
UVIS Crosstalk Satisfactorily
Resolved
• Extended source crosstalk (which could result from very
low level signals) is now undetectable (<0.1 e-)
– Combination of hardware change and timing pattern change
– New timing patterns show slightly improved read noise as well
(had been concerned they might have higher noise)
• No crosstalk in 2-amp readouts (i.e. from CCD to CCD)
• In 4-amp readout, small level of crosstalk remains from
saturated sources only
– New timing patterns slightly improve that level as well
– What remains is not a significant issue
preliminary analysis by S. Baggett
TIPS May 17, 2007
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UVIS Crosstalk Satisfactorily Resolved (2)
Performance w/Hardware Rev &
New CCD Timing Patterns
Original Problem
window-CCD ghost
filter-CCD ghost
crosstalk
source
stimulus artifacts
TIPS May 17, 2007
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Internal Cal Subsystem Illumination
Improved
• Severe glints reduced; see F390M flats below
• Count rate specs achieved
• As shown previously w/UVIS-1, Deuterium flats much improved in
uniformity (2× vs. 5-10×)
F390M (inverse) flat before
TIPS May 17, 2007
F390M flat now
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UVIS Grism Throughput Measured
UVIS grism
is WF/PC-1
spare; very
little
surviving
data
Data
provided to
SOC for ERS
planning
H. Bushouse
TIPS May 17, 2007
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CCD Charge Injection Working Properly
Mean charge injection
signal level
~16,000 e-/pix
Noise in a single
column ~15 e- rms
Much greater CTE
benefit than from a
lamp pre-flash of
equivalent noise level
TIPS May 17, 2007
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Improved Filter Ghost Performance
Confirmed
• Ambient cal measurements confirm the improved ghost performance
of the filters replaced in the SOFA
• Biggest success stories: F225W (<0.4% vs. 15%), F606W
(elimination of point-like ghosts), F280N (0.6% vs. 10-50% in ghost
and horrific scattered light flares)
Old
F225W
New
F225W
TIPS May 17, 2007
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UVIS-2 Detector Alignment
• UVIS-2 aligned at Ball on 30 Jan ’07
– used new, direct, “through the window” alignment transfer from
UVIS-1 to UVIS-2
• UVIS-2 within tolerance in 4 degrees of freedom, out in 2
• Additional adjustment of tip/tilt is desirable, if misalignment is
confirmed in upcoming TV#2 testing
UVIS-2 Alignment Summary
Apr '07
(Post-align) Tolerance
QX (o)
0.332
±0.20
QY (o)
-0.397
±0.20
QZ (o)
X (mm)
Y (mm)
Z (mm)
-0.032
0.251
0.032
0.276
±0.500
±0.300
±0.300
±0.850
TIPS May 17, 2007
16
UVIS-2 Misalignment Consequences
• At best focus, the performance degradation due to the current
level of tip/tilt misalignment is negligible, however …
• OTA breathing exacerbates the misalignment, causing a small
loss of performance over field, especially at short wavelengths
– Slight EE loss in small apertures
– PSF change (due to field dependent astigmatism inherent in optical
design)
TIPS May 17, 2007
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What’s Next?
• IR-1 detector package installation
– Received at GSFC yesterday (5/16); installation today
• System Level Thermal-Vac #2
– WFC3, with UVIS-2 and IR-1, into SES chamber ~5/29
– Ambient system functionals and alignment check ~6/1-6/5
– Vacuum testing for following ~75 days
• 24/7 support from STScI IS’s, DA’s, and Ops
– Proto-flight qualification of instrument
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Thermal cycling
Performance of all thermal systems
Full science calibration of UVIS and IR channels
CEI specifications verification
TIPS May 17, 2007
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IR FPA QEs
100
Quantum Efficiency (%)
90
80
70
IR3
60
50
IR1
40
IR2
30
20
10
0
200
IR Channel Wavelength Range
400
600
800
1000
1200
1400
1600
1800
Wavelength (nm)
FPA 64
FPA 129
TIPS May 17, 2007
FPA 150
FPA 160
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Backup slides
TIPS May 17, 2007
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UVIS-2 Misalignment EE Penalty
OTA SM
despace:
+3m
Nom
-3m
Detector
alignment:
Optimal
Optimal
As-is
As-is
TIPS May 17, 2007
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PSF Change with OTA Breathing
UVIS-2 CASTLE 633nm UV-11
-3m
0m
TIPS May 17, 2007
+3m
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FPA 160 Dark Current
% of Pixels Above Dark Rate
100
90
80
70
60
50
40
30
20
10
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Dark Current (e-/sec/pix)
FPA 64
FPA 129
TIPS May 17, 2007
FPA 150
FPA 160
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FPA 160 Persistence
TIPS May 17, 2007
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FPA 160 Read Noise
CDS Noise (e- rms)
FPA 64 (IR2)
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FPA 129 (IR1)
22
FPA 150 (IR3)
24
FPA 160
25
FPA 165
24
TIPS May 17, 2007
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FPA 165 QE
TIPS May 17, 2007
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SMGT preparations
• Revised SMGT Part 2 SMS
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Added UVIS Anneal exposures
Revised management of tungsten & D2 lamps
Corrected UVIS quad filter commanding
Duration of SMS is 20.5 hours
• Delivered SMS 3/30/2007 for test
– SMS ran successfully in VSTIF 4/23/2007
– Science data ftp’ed to STScI for OPUS processing
• Revised SOGS Support Schedules for SM4 Functional Test
– Science data from Early VEST test ftp’ed to STScI for OPUS processing
• Prepared OPUS for processing of VSTIF and Early VEST data
– Anomalies identified from February VSTIF run corrected
– Software testing and delivery complete by 5/2/2007
TIPS May 17, 2007
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SMGT Part 2 SMS Content
Visit
01
02
03
05
06
04
07
08
09
10
11
12
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14
15
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Content/purpose
Recovery from SAF E mo de.
CR-SPLIT 0 - 7, various apertures, filters.
1-hr exposure, Take Data Flag dropped.
CTE; DARK and Tungsten targets.
User & predefined sub-aperture; Selected ampl ifiers.
On-chip binning; Ampl ifier gain; Occulted target.
Selected ampl ifiers.
Deuterium lamp , high current.
Predefined dither patterns.
User sub-aperture.
Deuterium lamp , low and medium current.
Quad filters.
Quad filters.
CCD charge injection.
Deuterium lamp , low current.
UVIS optics alignment and focus.
Anneal.
Anneal with TEC disabled.
Bias exposure.
Transition UVIS to IR. Tungsten lamp . RAPID.
Transition IR t o UVIS. Dark target.
STEP200, STEP400, STEP600. Occulted target. Grating.
SPARS10. Various aperture s. Dither patterns.
SPARS25, SPARS50, SPARS100. Sub-arrays.
Predefined dither patterns.
SPARS200, STEP25, STEP50, STEP100. Sub-array.
MIF900, MIF1200, MIF1500.
IR optics alignment and focus.
SMOV special comm andin g for memory dump.
Config.
SC
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
UVIS
SC
SC
UVIS
IR
UVIS
IR
IR
IR
Dur.
[hr]
0.11
5.13
1.13
0.39
0.41
0.61
0.15
0.07
0.75
0.13
0.05
0.25
0.23
0.70
0.05
0.79
0.04
0.01
0.13
1.18
0.14
0.43
0.54
0.29
IR
IR
IR
SC
0.20
0.19
0.81
0.08
TIPS May 17, 2007
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Preparation of
SMGT Part 2 SMS
Anomaly
Subsystem
Assignee
Status
Update UVIS & IR filters (F588NF200LP &
F098WF140W)
Errors in SIAF aperture specifications
APT, IM
ESS
Closed
TRANS
OBS/TEL
Closed
Incorrect reporting: errors for NICMOS; CRSPLIT exp.
ANNEAL not used
Detector temperature set-points raised for
ambient
Mosaic dithers generate pointing warnings
Tungsten lamp on during readouts
Patch SMS for CS 3.0 D limits
Error inhibiting 6-stage TEC for ambient tests
APT
OED
Closed
N/A
IM
INS/WFC3
OED
Closed
Closed
APT
TRANS
IM
IM
OED
INS/WFC3
OED
OED
Closed
Closed
Closed
Closed
TIPS May 17, 2007
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SMGT VSTIF Results
Anomaly
Subsystem
Assignee Status
UVIS full-frame exposures fail in Generic Conversion
OPUS/GC
DPT
Closed
Errors in IR dark reference file keyword values
CDBS
INS/WFC3 Closed
Incorrect IR dark reference file selection for subarrays
CDBS
INS/WFC3 Closed
IR subarray format not listed in science image headers
KWDB
DPT
Closed
Incorrect WFC3 SIAF values
SIAF
OBS/TEL Closed
Incorrect CCD amp selection for UVIS Quad filters
Commanding
SCSB
Closed
Inadequate representation of UVIS Quad filters in use
OPUS/GC INS/WFC3 Open
Generic Conversion still using old IR readout times
OPUS/GC
DPT
Closed
Incorrect PRIMESI keyword values
OPUS/GC
DPT
Closed
Incorrect PHOTMODE keyword values
CALWF3
INS/WFC3 Closed
CALWF3 IR dark frame selection enhancement
CALWF3
INS/WFC3 Closed
Updated IR dark calibration reference files needed
CDBS
INS/WFC3 Closed
TIPS May 17, 2007
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