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NIRCam Monthly Science Team Telecon

March 6, 2008

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JWST Project Status

• Project team is working hard to finish preparations for the Mission Preliminary Design Review to be held March 31 – Apr 4. NIRCam has been involved in a number of discussions about

modification of the wavefront sensing process driven by the realization that some aberrations have a strong field dependence. Likely solution is to use data from the FGS in addition to that from NIRCam.

• ISIM financial problems were resolved without changing the flight NIRCam at all. Some extra ETU and flight alignment checks were removed from the plan. ISIM-level ETU testing was also removed.

• Pam Sullivan, the ISIM Manager, is leaving to become deputy project manager on another GSFC mission. Jamie Dunn, her deputy, will become the ISIM Manager.

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NIRCam Status• Key deliveries are happening

All but 2 filters have passed their pre-ship reviews at Barr. F466N and F470N have some visible hazing and slightly low transmission (58% vs 60% req) which is being investigated.

New LN2 shroud for the thermal-vac chamber has been received. Testing shows that the chamber can be cooled to as low as 11K so we have some margin.

Many items for building ground support equipment are arriving• John Miles will become the LM ATC Integration and Test Lead

for NIRCam.• Pathfinder optics are now assembled and aligned and will

undergo cold test shortly• LW grism production is proceeding very well • Preparations for Qual FPA build are finished

Fit check of dummy FPA into GL dewar went smoothly with no handling problems.

Qual SCAs tested and report writing is in progress Metrology dewar ready

4

Bench Work

• ETU bench has been delivered but significant amounts of non-volatile residue were discovered. A procedure was developed to remove the material but is has been tedious and taken much more time than expected.

• Dress rehearsal for epoxy bonding the bench halves together went well as did the test of the emergency epoxy removal procedure

A minor mishap with an air hose removed a small (0.1”) chip from one rib. Fortunately no cracks formed and so this became a good reminder about how careful one must be when working around these benches.

Jigsaw configuration matches OBA

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Qual FPA

• Qual FPA structure has been populated with dummy SCAs as fit and procedure checks.

• Next step will be to mount the 4 Qual SCAs (C033, C034, C042, and C048) to the structure

• Qual will be subjected to metrology and performance tests both before and after vibe

• Have baseline performance data for the SCAs in hand

Top view w/ dummy SCAs.

Side view showing struts and cables.

Bottom view showing connectors and optical cube.

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SCA Production Issue: Edge Effects

Detector not connected to readout multiplexer around SCA perimeter – problem has been variabel with only some parts showing the problem.

Teledyne has stoped SCA production temporarily until they are convinced the problem is solved.

Investigation so far suggests that contamination during indium bump bonding is the likely culprit.

We are investigating data from repeated cooldowns on several parts to check whether additional pixels open up over time from repeated thermal cycles.

Could become a schedule threat for NIRCam if not resolved soon.

2K x2K HybridLacks interconnect

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C084 Preliminary Dark Current 5 micron SCA

Median dark current is 0.0126 e-/sec Two glowing areas apparent

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C084 Preliminary Total Noise 5 micron SCA

Median total noise is 6.57 e-

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ETU Calibration Source Parts

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ETU PAPPA

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Universal Nudger Handle Assy.

KnurledHandle

LEDWarning Light

ContactBody

M6 NudgerInterface

Straight StickNudger

Bent StickNudger

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Girls Scouts Greet the ETU Bench

Girl Scouts came to watch the delivery.

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IOA Mass History

170.00

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Dec-02 Jun-03 Jan-04 Aug-04 Feb-05 Sep-05 Mar-06 Oct-06 Apr-07 Nov-07 Jun-08

Mas

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Predicted Basic Allocation SRR PDR CDR