May 19, 2009JWST Partner's Workshop1 NIRCam Status Marcia Rieke University of Arizona JWST Partner’s Workshop Ottawa, Canada May 19, 2009 JWST-PRES-012902

May 19, 2009 JWST Partner's Workshop 1

NIRCam Status

Marcia RiekeUniversity of Arizona

JWST Partner’s Workshop

Ottawa, Canada May 19, 2009

JWST-PRES-012902


Read Noise with ASICs

State Read Noise Electrons*

CDS Electrons*

Set 06 Only J3 = C042 Running 8.9 21.6 Set 07 All running in synch 8.2 21.7 Set 08 All running, not in synch 8.4 22.1 Set 09 All running out of synch, ASIC

exp/idle start delay of 9 usec 8.1 21.6

Set 10 Detector victim = C042 13.8 21.8 Set 11 C042 alone, single-ended 14.1 38.2 Set 12 ASIC input shorted 2.7 9.6

A set consisted of 30 80-sample ramps.

Data taken using development unit ASICs and Qual FPA


How to Use Subarrays

An open question in using the subarray readout mode is whether special calibrations are needed for each subarray location and size or whether data can be extracted from full frame data. • For 2-sample (CDS) data, we may recommend taking darks before the exposure

– SCAs run from an ASIC may not have the reset anomaly that we see running in buffered mode w/ a Leach controller

• Reference pixels do not provide any benefit.

– Again need to be careful about possible ASIC vs Leach or buffered vs unbuffered mode caveats

• Flats can be used from full frame data.

• no ref pix corr

• ref pix corr


Illuminated Subarrays

Arrays run simultaneously so LED variations are seen in all.

NIRCam will use a subarray or “window” readout mode to extend dynamic range. It may be the principal mode for observing transits by extra-solar planets.

A 128x128 subarray was used with four SCAs (two shown here) in our test dewar. Illumination was provided by 2micron LED, and a series of 2-sample ramps were taken.


Subarray Flatfielding

Gray scale and plot show the result of ratioing subarray to full frame data. Neither image was linearity-corrected. The variations of +/-2% agree with expectations from counting statistics. Full frame flats appear to be fine for use with subarrays.

0.90

0.92

0.94

0.96

0.98

1.00

1.02

1.04

1.06

0 20 40 60 80 100 120 140 160

Pixel Number

Rat

io


C038 C045

C044 C043

FM1 Dark (black is good)

B1B3

B4 B2

B1B3

B4 B2

FM1 Illuminated(white is good)

Red box is coronagraphy field.

Flight Short Wavelength FPAs are in Assembly


C074C105

C104 C101

A4 A2

A1A3

FM2 Dark

(black is good)

FM2 Illuminated

(white is good)

Red box is coronagraphy field.


Flight Wide Filters• Plot below shows the transmission functions for the flight candidates. Dashed line is the requirement.

• Out of band blocking is also excellent.

Req.


ETU Optic Test Pupil Wheel ConfigFWA ETU Optic Test

PW2 – FLAT FIELDPINHOLES

PW3 – Uncoated

Fused Silica

PW10 – Uncoated

Fused Silica

PW11 – WEAK LENS -

6

PW12 – ETU DHS 2

PW1 – CIRCULARAPERTURE

PW9 – WEAK LENS -

7

PW7 – FILTER

SURROGATE

PW6 – DHS MASS

SURROGATE

PW4 – FILTER

SURROGATE

PW8 – OUTWARDPINHOLES

PW5 – FILTER

SURROGATE


ETU Optic Test Filter Wheel ConfigFWA ETU Optic Test

FW8 – FILTER F187N

FW12 – DHS FILTER

F150W2

FW11 – FILTER

F070

FW9 – IMAGING

PUPIL

FW1 – FILTER

SURROGATE

FW10 – FILTER

SURROGATE

FW7 – WEAK LENS

- 8

FW3 – FILTER F115W

FW4 – FILTERF070W

FW5 – FILTERF200W

FW6 – FILTERF212N

FW2 – FILTER

SURROGATE

Optics used in acceptance test


DHS Element in ETU Pupil Wheel


• Precision alignment and KOH bonding of ETU PIL optics is complete• Assembly is being integrated with mechanism for further environmental tests

ETU Pupil Imaging Lens Assembly


ETU Short Wave Fold Mirror Assembly

WFE Pre-Vibe: 11.4 nm rms

WFE Post-Vibe: 11.8 nm rms

Vibration ConfigurationSWFM Assembly


ETU SWFM Cryo-cycling Results

Mirror exceeded spec in first Cycle, then maintained acceptable surface figure through Cycles 2 and 3

Note: chart shows only data points taken at points of thermal equilibrium

ETU SWFM Surface Figure vs Temperature

0

50

100

150

200

250

300

350

1/21/090:00

1/22/090:00

1/23/090:00

1/24/090:00

1/25/090:00

1/26/090:00

1/27/090:00

1/28/090:00

1/29/090:00

1/30/090:00

1/31/090:00

0

5

10

15

20

25

30

SWFM Temp

Surface Figure (Window subtracted)

Requirement17.8 nm (CA)

Bottom of 3rd Cycle: 13.8 nm rms


Progress on Wavefront ErrorRecall that the NIRCam optical train as first realized in the Pathfinder did not meet its wavefront error requirement.

Several causes were identified: 1) Mount-induced distortion 2) Coating-induced distortions 3) Poor alignment of lenses within a triplet An improved alignment scheme is helping, and the coating problem has been traced to thermal shock at JDSU. A new bonded mount design is the last improvement.


Short Wave Bonded ZnSe Singlet

“Optic Saver” Standoff

-40. -24. -8. 8. 24. 40.0.-40.

-32.

-24.

-16.

-8.

0.

8.

16.

24.

32.

40.

NIRCam Mono OTE Rev E long-wave LW and short-wave SW CFG 1SURFACE NOS 118 THROUGH 119LENS Y,Z PROFILEOffset (X,Y) 0.0000 0.0000X-SCALE = 8.00000 MMY-SCALE = 8.00000 MM

Lockheed Martin Adv. Tech. Center1645 HRS 7 May 09Torben B. Andersen


Surface figure cooldown of SW ZnSe S1

Surf fig rms = 2.85nm

Zernike coeffs for surface S1 deformation (mm) N M A(N,M) 0 0 -5.183155E-10 { Piston 1 0 1.300426E-10 { X-tilt 1 1 -1.121232E-09 { Y-tilt 2 0 -5.291451E-09 { Astigmatism +-45 2 1 1.448882E-06 { Focus shift 2 2 1.274113E-09 { Astigmatism 0 or 90 3 0 -3.222958E-11 { Trefoil Y 3 1 2.269643E-08 { Coma 3rd ord Y 3 2 2.980256E-09 { Coma 3rd ord X 3 3 -8.016083E-06 { Trefoil X 4 0 1.895118E-09 { Tetrafoil Y 4 1 -7.188401E-10 4 2 2.088516E-07 { Spherical 3rd + Focus 4 3 2.122979E-09 4 4 -4.484867E-09 { Tetrafoil X 5 0 -2.934174E-09 { Pentafoil Y 5 1 -4.836911E-11 5 2 7.533641E-09 { Coma 5th ord Y 5 3 -3.353857E-09 { Coma 5th ord X 5 4 -3.639932E-07 5 5 4.083817E-10 { Pentafoil X 6 0 1.082787E-09 { Hexafoil Y 6 1 2.653164E-09 6 2 -5.562098E-09 6 3 -5.657147E-08 { Spherical 5th + 3rd + Focus 6 4 2.971023E-09 6 5 8.877737E-10 6 6 -4.649130E-06 { Hexafoil X


Surface figure cooldown of SW ZnSe S2

Surf fig rms = 2.74nm

Zernike coeffs for surface S2 deformation (mm) N M A(N,M) 0 0 2.525041E-10 { Piston 1 0 2.993422E-10 { X-tilt 1 1 7.632050E-10 { Y-tilt 2 0 -5.971137E-09 { Astigmatism +-45 2 1 -3.263482E-06 { Focus shift 2 2 5.627774E-09 { Astigmatism 0 or 90 3 0 -4.283727E-10 { Trefoil Y 3 1 1.133856E-07 { Coma 3rd ord Y 3 2 5.183714E-08 { Coma 3rd ord X 3 3 -5.874208E-06 { Trefoil X 4 0 8.810965E-10 { Tetrafoil Y 4 1 1.763393E-09 4 2 8.018278E-07 { Spherical 3rd + Focus 4 3 -4.894394E-10 4 4 -9.632704E-10 { Tetrafoil X 5 0 1.724538E-10 { Pentafoil Y 5 1 -6.425059E-10 5 2 5.631900E-09 { Coma 5th ord Y 5 3 2.292512E-09 { Coma 5th ord X 5 4 -2.042380E-07 5 5 8.014672E-11 { Pentafoil X 6 0 -1.364540E-09 { Hexafoil Y 6 1 3.202912E-09 6 2 -7.377090E-10 6 3 1.018624E-06 { Spherical 5th + 3rd + Focus 6 4 3.032352E-09 6 5 -1.312308E-09 6 6 -2.458051E-06 { Hexafoil X


Differences in transmitted WFE in NIRCam SW Path at 2.0m for 5 field points from cool-down

mount-induced surface figure changes

SW ZnSe lens

rms = 2.08nmrms = 2.15nm

rms = 2.09nmrms = 1.97nm

rms = 2.48nm

Prediction is 2.48 nm versus 8.02 budget allocationPrediction is 2.48 nm versus 8.02 budget allocation


Test Article

Margin of Safety Tests

Bonding Tests

Epoxy samples for testing.

• Sample lens substrates with metal pucks attached have successfully been cryo-cycled to 16K

• Characterization of epoxy samples for CTE and other properties is underway

• Margin of safety test has been designed with testing to occur in June


ETU Build Flow

Cold Alignment Cycle 1



CheckStability

Nudge

Install PIL,

FPA

Install Baffle Covers

AT

AT

AT

FPA & Wavefront

Sensing TestsATAT

AT

Module B Plug ‘n’

Play, Pt 1

AT

TRR

TRR

OMA Tolerance

Review

OMACalibration

Review

WFE Review

OMA Build

OMA Calibration

OMATRR

WarmAlignment Data

Review

Predict WFE, focus with

OMA

OMA Tolerance Analysis

Predict WFE with p-SMART

Module B Plug ‘n’

Play, Pt 2

p-SMART Test

SFPA / SMART Metrology

AlignmentPlan Review

Monte Carlo Analysis Review

WFS ReviewModule

Integration

August

Delivery to GSFC in Oct.

Documents

May 19, 2009JWST Partner's Workshop1 NIRCam Status Marcia Rieke University of Arizona JWST Partner’s Workshop Ottawa, Canada May 19, 2009 JWST-PRES-012902