TIPS meeting – Feb 21, 2002
WFC3 Status (detectors)
M. Robberto
UVIS CCD
IR FPA / Mux
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
1
CCD Status
• Marconi has completed all deliveries.
– Original order of 6 devices.
• One (# 23) damaged back in Nov 01 and returned to Marconi for analysis
• Four (# 18 & # 178 and # 37 & # 40) selected for flight and characterized.
• One held in reserve.
– Supplemental order of 2 devices.
• Both (# 48 and #50) received, characterization of #38 underway in the
DCL.
– Closeout meeting held on 15 January 2002.
– Last detectors #37, #40, #50 shipped at Ball next week
• These are exceptional devices, with extremely uniform
behavior from device to device.
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
2
WFC3 CCD Innovations
• Low readout noise.
– Improves narrow-band and UV imaging sensitivity and enables shorter
sub-exposures in a long integration (providing more redundant images or
more thorough drizzling).
– Will challenge the instrument electronics.
• High near-UV QE.
– Major WFC3 scientific thrust is enabled.
• Extremely uniform detector spatial response.
– Simplifies calibration and improves photometric accuracy.
• Charge injection for CTE degradation mitigation.
– Slows down effective device aging.
• Fringing characterization and prediction for long wavelength
observations.
– Improves accuracy of narrow-band and narrow-line observations.
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
3
Marconi CCDs Have
Very Low & Consistent Readout Noise
Read Noise For Marconi CCD43 Engineering Grade Devices
#187
#165
#188
#152
#189
#166
Units Spec Marc. DCL Marc. DCL Marc. DCL Marc. DCL Marc. DCL Marc. DCL
RN (A) e3
1.6
2.9
2.6
3
1.7
3.2
2.4
3.5
3.3
(B) e
3
1.7
1.8
2.6
2.9
1.6
3
1.6
3.5
3.6
Read Noise For Marconi Flight Candidate Devices
#136
#178
#018
#023
#037
#040
#050
Units Spec Marc. DCL Marc. DCL Marc. DCL Marc. DCL Marc. DCL Marc. DCL Marc. DCL
RN (A)
(B)
-
e
e-
3
3
3
3.5
3
2.2
3.1 <2.7
3
2.3
3.1 <2.7
Flight pair number 1
2.9
3
2.8
3.4
2.1
3.1
3.5
3.1
2.2
3.1
--- Flight pair number 2 candidates ---
By comparison, the SITe devices in the ACS instrument have
read noises in the range 4.5-5.5 e"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
4
Marconi CCDs Exceed Expectations for
High UV QE
Pair Number 1 flight CCDs versus the Specification
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
5
IR-FPA Status
Detector
#
Produced
11
13-Mar-01
14
30-Mar-01
15
18-Apr-01
18
20-Apr-01
20
20-May-01
21
25-May-01
22
13-Jun-01
24
14-Jun-01
25
6-Jul-01
27
19-Jul-01
30
1-Aug-01
31
23-Aug-01
32
4-Oct-01
33
13-Sep-01
34
14-Oct-01
MILESTONES
Due
Delivered
9-Apr-01 27-Apr-01
23-Apr-01 27-Apr-01
23-Apr-01 16-May-01
4-Jun-01 8-Jun-01
4-Jun-01 8-Jun-01
4-Jun-01 8-Jun-01
6-Jul-01 18-Jul-01
6-Jul-01 18-Jul-01
6-Jul-01 18-Jul-01
3-Aug-01 7-Sep-01
3-Aug-01 7-Sep-01
3-Aug-01 12-Oct-01
4-Oct-01 26-Oct-01
4-Oct-01 12-Oct-01
4-Oct-01 26-Oct-01
Test report
26-Mar-01
10-May-01
30-May-01
11-Jul-01
18-Jul-01
20-Jul-01
1-Sep-01
1-Sep-01
1-Sep-01
15-Oct-01
8-Nov-01
1-Oct-01
8-Nov-01
9-Nov-01
9-Nov-01
Comments
pixel crosstalk
pixel crosstalk
QE non-uniformity at cutoff
at Ball, integrated into qual unit
warm image shows unbonded pixels
Flight backup candidate
Flight backup candidate
Flight candidate
Flight candidate
 In addition, MUX #10 was delivered to Ball and is being integrated into
the surrogate IR detector build
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
6
Rockwell Test Results
FPA #
Parameter
Gain
Read noise
Dark Current
Units
e-/mV
e-/pix
e-/pix/sec
e-/pix/sec
Persistence
after 96 min
QE @ J
%
QE @ 1.5 m
%
Operability
%
keFull Well
Parameter
Gain
Read noise
Dark Current
11
361
65
0.5
14
0.6
15
300
40
0.049
18
321
47.2
0.34
20
315
47
0.37
21
274
39
0.104
22
315
43
0.388
24
315
47.5
0.357
1.42
45.2
58.8
0.504
47.1
50
>99.7
>102
>99.1
>100
72.7
86.1
27.9
31.2
24
27.1
20.6
33.8
42.7
64.6
0.165
32
44.4
>99
>97
>99
>99
>97
>90
>97
>85
Units
25
e /mV
308
e /pix
e /pix/sec 0.153
e-/pix/sec
Persistence
after 96 min 0.499
QE @ J
%
50.6
QE @ 1.5 m
%
68.2
Operability
%
>99.2
ke
Full Well
>104
27
499
68.8
0.136
30
350
57.7
0.133
FPA #
31
347
44.7
0.037
0.207
39
53.6
0.43
43.8
55.9
0.067
61.3
81.1
0.083
25.4
39.3
0.125
55.1
76
0.055
28.4
38.9
>99.7
>150
>99.8
>110
>99.7
>100
>99.7
>110
>99.7
>100
>99.6
>132
32
300
33.9
0.086
33
332
48.1
0.129
34
360
42.1
0.041
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
7
RSC Dark Current and QE
Results
min
The dark current
and QE
performance of
the detectors
showed dramatic
improvement
over the course
of the program
100%
100%
min
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
8
Dark current
1
y = 3E-17e0.2313x
0.01
10
0.001
140
145
150
155
160
165
Temperature (K)
FPA15:
DC= 0.04e/s @ 150K
1
10
0.1
0.01
135
140
145
150
155
160
temperature (K)
FPA18:
DC= 0.34e/s @ 150K
165
dark current (e/s)
0.0001
135
dark current (e/s)
dark current (e/s)
0.1
1
0.1
0.01
144
146
148
150
152
154
temperature (K)
FPA22:
DC= 0.39e/s @ 150K
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
9
156
FPA31 dark current ramps
FPA31
exposure
FPA31010800s
7200s Exposure
Dark Current vs Read Number
d07_150k_dk_00XX.fits
59000
01
02
03
58000
04
05
06
Mean Sci Pix (DN)
57000
07
08
09
56000
10
11
12
55000
13
14
15
54000
16
18
20
53000
22
1
3
5
7
9
Read Num ber
11
13
15
17
24
C. Hanley 11 Jan 2002
• Ramp slope decreases with time
• Second read decreases with time
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
10
FPA31 dark current settling time
Cycle power
FPA31
Mean Signal in Last Read vs Time
59000
A sequence of 20 ramps 3 hr
long, each with 1+16 samples
(one every 675s)
58000
Mean Sci Pix (DN)
57000
56000
55000
54000
53000
0
50000
100000
1day
150000
Time (seconds)
200000
250000
2days
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
11
FPA31 dark current settling time
Cycle power
FPA31 Dark Current Over Time
0.2
{
CEIS
0.1
0
Dark Current (e-/s)
-0.1
-0.2
-0.3
-0.4
-0.5
FPA31 dark current settles
after ~ 2 days
-0.6
-0.7
-0.8
0
50000
100000
1day
150000
Time (seconds)
200000
250000
2days
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
12
FPA31 dark anomaly
FPA31 appears to have
two populations of pixels,
each with their own dark
current behavior.
November 01 data
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
13
FPA31 dark – 2 populations
1hr
1hr
1hr
October 24 data
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
14
Dark current summary
• FPA31 dark current is ~0.05e/s/pix, once the FPA is set.
• Settling time is ~36 hr.
• For the first ~36 hr the dark current is dominated by a large
drift in the output signal.
• Irregular behavior still present after 36 hr on short ramps.
• The drift is similar to the “reset anomaly”, but it has larger
time-scale and is related to the FPA power cycling. Reset
anomaly can be corrected.
• Power cycling of IR FPA is not expected to routinely occur
on WFC3.
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
15
Quantum efficiency
FPA31
1.0
0.9
0.8
0.7
Q1
Q2
0.6
Q4
0.5
Q3
OK
0.4
$
0.3
$$
0.2
0.1
0.0
500
700
900
1100
1300
1500
1700
1900
January 11 data
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
16
Readout noise
active area
electrons
electrons
inboard
36
12
34
10
32
8
30
SB Jan 16,2001
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
17
Readout noise
Summary of the RON measured on active pixels
•
•
•
•
•
FPA#15:
FPA#18:
FPA#22:
FPA#25:
FPA#31:
32 e/pix/read
30 e/pix/read
30 e/pix/read
28 e/pix/read
31 e/pix/read
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
18
Reference pixels
4507 horizontal
1507 horizontal
1014  1014
active pixels
1507 vertical
4507 vertical
1014  5 reference pixels
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
19
Fixing reference pixels
Vertical reference pixels are “light sensitive”
Adding a delay time at the beginning of each line read eliminates the effect
50
1ms
0ms
45
2ms
3ms
8ms
40
35
adu
30
Horizontal
25
Vertical
20
15
10
5
0
0
6
12
18
24
30
Fowler DCS
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
20
Reference pixels drift in 60hr
59000
dark
57000
vertical
horizontal
Reference pixels are stable within ~100e
over a time-scale of ~2.5 days
53000
51000
49000
47000
45000
0
50
100
150
200
250
300
sample
46200
horizontal
vertical
46150
46100
counts
counts
55000
46050
46000
45950
45900
0
50
100
150
200
250
300
sample
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
21
CONCLUSIONS
FPA 31 has been deeply investigated
• QE above Performance Specs at l>1.35m
below Minimum Specs at l<1.2m
• Dark Current meets specs by a factor ~4, but
– Needs ~ 36hr to settle
– Irregular behavior common for short exposure times
•
•
•
•
•
RON ~30 electrons/read
Linearity and well depth
Amplifier glow
Cosmetic
Reference pixels
OK
NO
??
NO
NO
OK
OK
OK
OK
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
22
• One between FPA#31 or FPA#33 to be delivered next
week
• Rockwell has produced two extra non-flight parts,
FPA#35, #36 currently under test. Preliminary data
confirm QE and RON measured at DCL.
• Rockwell has delivered to UH (D. Hall) a detector with
5m material and HI-1R MUX for RON test.
• Rockwell has agreed to grow LOT 5. Expected 6-8 weeks
for PECs/test device data and 4 months for flight parts.
• Contractual issues worked on.
• New plan for 2nd detector build under discussion with
BALL.
"Data contained herein is exempt from ITAR regulations under CFR 125.4(13) -- data approved for public disclosure."
February 21, 2002
TIPS meeting
23