1. The James Webb Space Telescope & its Infrared Detectors Bernard J. Rauscher 1 & Mike Ressler 2 for the JWST Team 1 NASA Goddard Space Flight Center 2 NASA Jet Propulsion Laboratory 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 1

2. JWST’s Detector Partners 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 2 University of Arizona Raytheon Vision Systems University of Rochester The following individuals contributed material on JWST detectors to this presentation James Garnett, Rockwell Scientific Alan Hoffman, Raytheon Vision Systems Markus Loose, Rockwell Scientific Craig McMurtry, U. Rochester In addition, we have drawn on other JWST-related documents as needed. These are cited when it is practical to do so.

3. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 3 Presentation Overview JWST Science JWST Mission Instruments, Detectors, and ASICs Cosmic history from the Big Bang to today. JWST will elucidate the end of the dark ages and the beginnings of the galaxies that we see today. Spiral galaxy M81 seen in: (1) optical/Kitt Peak and, (2) 3.6  m, (3) 8  m, and 24  m and (d) composite Spitzer images. JWST’s near and mid-IR wavelengths offer a very different perspective on the Universe compared to optical!

4. Top JWST Goal - Find the First Light after the Big Bang How and from what were galaxies assembled? What is the history of star birth, heavy element production, and the enrichment of the intergalactic material? How were giant black holes created and what is their role in the universe ? Three instruments to do this: NIRCam (NASA/CSA), NIRSpec (ESA), MIRI (ESA/consortium/NASA), plus FGS-TF (CSA)     as seen by COBE Galaxies, stars, planets, life Galaxy assembly ? ?

5. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 5 JWST Science Birth of stars and protoplanetary systems Planetary systems and the origins of life Galaxies in the UDF End of the dark ages: first light and reionization The assembly of galaxies The Eagle Nebula as seen by HST The Eagle Nebula as seen in the near-infrared

6.  Mission Objective –Study the origin and evolution of galaxies, stars and planetary systems Optimized for infrared observations (0.6 –28  m)  Organization –Mission Lead: Goddard Space Flight Center –International collaboration with ESA & CSA –Prime Contractor: Northrop Grumman Space Technology –Instruments: –Near Infrared Camera (NIRCam) – Univ. of Arizona –Near Infrared Spectrograph (NIRSpec) – ESA –Mid-Infrared Instrument (MIRI) – JPL/ESA & European Consortium –Fine Guidance Sensor (FGS) – CSA  Description –Deployable telescope w/ 6.5m diameter segmented adjustable primary mirror –Cryogenic temperature telescope and instruments for infrared performance –Launch in 2012 to Sun-Earth L2 –5-year science mission (10-year goal) James Webb Space Telescope (JWST) today www.JWST.nasa.gov Concept DevelopmentDesign, Fabrication, Assembly and Test mission formulation authorized confirmation for mission implementation launch science operations...

8. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 8 0 JWST Inserted into L2 Orbit

9. ISIM Overview ISIM is: The JWST Science Instruments Associated Infrastructure: Structure, C&DH, & FSW Region 1 Science Instrument Optics Assemblies Near Infrared Camera (NIRCam) Near Infrared Spectrograph (NIRSpec) Mid Infrared Instrument (MIRI), & Dewar 1 Fine Guidance Sensor and Tunable Filter (FGS/TF) Optical Bench Structure Radiators and support structure (NGST-supplied) Region 2 Focal Plane Electronics (FPE) Instrument Control Electronics (ICE, MCE) Region 3 ISIM Command & Data Handling (C&DH) Electronics 1 The dewar was recently deleted. MIRI will use a cryocooler.

10. Fine Guidance Sensor (FGS) Ensures guide star availability with >95% probability at any point in the sky Includes Narrowband Imaging Tunable Filter Module CSA/EMS provided 2 (2048x2048) 68mas pixels John Hutchings, lead Mid-Infra-Red Instrument (MIRI) Distinguishes first light objects; studies galaxy evolution; explores protostars & their environs Imaging 1 (1024x1024) 110mas pixels Spectroscopy (R~3000) 2 (1024x1024) 200-470mas pixels 5 to 27 microns; Cooled to 7K by cryocooler ESA/JPL, George Rieke, Gillian Wright leads Instrument Overview Near Infra-Red Camera (NIRCam) Detects first light galaxies and observes galaxy assembly sequence 0.6 to 5 microns, 2 (4096x4096) 31mas pixels & 2 (2048x2048) 62mas pixels Supports Wavefront Sensing & Control Univ. of AZ - LMATC instrument; Marcia Rieke, PI Near Infra-Red Spectrograph (NIRSpec) Measures redshift, metallicity, star formation rate in first light galaxies 0.6 to 5 microns Simultaneous spectra of >100 objects 2 (2048x2048) 100mas pixels Resolving powers of ~100, ~1000, ~3000 ESA/Astrium provided, with NASA Detectors & Microshutter Former location of dewar

11. Rockwell Scientific selected for NIRCam, NIRSpec and possibly FGS –Total of 19 Hawaii-2RG sensor chip assemblies (SCAs) for flight and flight spare Raytheon Vision Systems selected for MIRI –Total of 6 SB-305 SCAs for flight and flight spare Infrared Detectors for JWST

12. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 12 Near-Infrared Detector Technology Development NICMOS 256x256 HgCdTe WFC3 1024x1024 JWST Proto-type 4Kx4K NICMOS and IRAC arrays demonstrated the basic detector architecture but with lower performance and smaller formats. TRL 4 achieved Feb 2002 with JWST performance levels achieved TRL 5 achieved Feb 2003 with JWST size 2Kx2K devices, mosaicing Astronomical Image with prototype, Sept. 2003

13. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 13 Image with JWST Prototype Detector NGC 891 test image with Rockwell HgCdTe 4Kx4K array, Sept. 2003 The first astronomical image to be obtained on JWST flight prototype near- infrared detectors. This three color image of the galaxy NGC891 was obtained using a 4096 x 4096 HgCdTe array produced by Rockwell Scientific Corporation under contract to JWST and the University of Hawaii KSPEC instrument on the UH 88 inch telescope.

14. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 14 Near-Infrared Detector Readout & Control SCA Control by Rockwell SIDECAR ASIC One ASIC per SCA Demonstrated performance met challenging JWST requirements in Feb., 2005 JWST will fly a total of 16 near-infrared SCAs and 16 SIDECAR ASICs

15. Near-Infrared SCA Performance with SIDECAR ASIC Quiescent lab conditions Raw data & noise measurements as reported by Rockwell Independent analysis of the same data at NASA/GSFC confirms Rockwell findings for CDS and MULTIACCUM*. Did not look at Fowler sampling Flight representative –2.5  m cutoff SCA –SCA to ASIC electrical interfaces –ASIC *For the data that were provided, we found that we needed one additional calibration step compared to Rockwell. The additional step was similar to correcting for a small pedestal drift. It was needed because the reference pixels did not perfectly track the regular pixels. Baseline NIRSpec mode shown in Red. Uses 88 non-destructive samples up t~1000 s ramp. The above figure was presented by Rockwell Scientific as part of an ASIC review package. Test data and analysis are by Rockwell staff. Total Noise per 1000 s

16. SIDECAR ASIC has demonstrated excellent noise performance that exceeds the requirements for all three near-infrared instruments (37 K SWIR H2RG + ASIC) SIDECAR ASIC Exceeds JWST Noise Requirements Noise at low bias 1 Noise at medium bias 1 JWST Requirement ASIC by itself (NIRSpec 4-22 multiaccum) 2.0 e-1.8 e- 2.4 e - (NIRSpec) ASIC + HAWAII-2RG CDS 16.5 e-16.2 e- 3 24 e- (extrapolated) ASIC + HAWAII-2RG Fowler 8-8 6.8 e-6.7 e- 9 e- (NIRCAM) ASIC + HAWAII-2RG (4 –22 multiaccum) 5.3 e-5.2 e- 2,3 6 e- (NIRSpec) 1 100 kHz pixel rate 2 MULTIACCUM-22x4 calculated using 4 out of 6 measured ramps due to larger frame-to-frame pedestal in remaining 2 ramps. 3 Analysis of test data independently confirmed by NASA/GSFC Test results & analysis reported on this slide provided by Rockwell Scientific. Except where indicated, they have not yet been independently confirmed by NASA/GSFC.

17. Near-Infrared Dark Current Tests Have Achieved the Required Levels Engineering Unit JWST-009, substrate removed SWIR array, dark current histogram and map Test results reported on this slide provided by Rockwell Scientific Test results & analysis reported on this slide provided by Rockwell Scientific. Except where indicated, they have not yet been independently confirmed by NASA/GSFC.

18. Visible QE Exceeds 80% at 800 nm Engineering Unit JWST-009, substrate removed SWIR array, QE histogram and map at 800nm - illumination non-uniformity not removed Test results reported on this slide provided by Rockwell Scientific Test results & analysis reported on this slide provided by Rockwell Scientific. Except where indicated, they have not yet been independently confirmed by NASA/GSFC.

19. Longer Wavlength QE Exceeds 80% As Expected Engineering Unit JWST-009, substrate removed SWIR array, QE histogram and map at 1230nm - illumination non-uniformity not removed Test results reported on this slide provided by Rockwell Scientific Test results & analysis reported on this slide provided by Rockwell Scientific. Except where indicated, they have not yet been independently confirmed by NASA/GSFC.

20. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 20 Mid-Infrared Technology Development Concept studies for a JWST mid-IR instrument begun in 1997 Tentative detector requirements laid out in these studies Craig McCreight led the Detector Working Group in 1999 –Looked at all technologies applicable to JWST –Concluded Si:As IBCs were most mature for mid-IR –Produced “Document 641” – JWST detector roadmap Contract with Raytheon in ~ 2000 to develop Si:As technology for JWST established by Craig JPL selected as U.S. MIRI lead in 2001 MIRI detector competition announced in early 2003 Raytheon competitively selected in May 2003 PDRs begun in August 2003 that finalized design Hybrid shown in a non-flight test mount

21. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 21 MIRI Focal Plane Primary Requirements Parameter Format Detector Material Noise (Fowler-8 sampling) Dark Current QE:5 – 6 um 6 – 12 um 12 – 26 um 26 – 28.2 um Requirement 1024 x 1024 Si:As IBC < 19 e- @ 7.1 K < 0.03 e-/sec @ 7.1 K > 40% > 60% > 70% > 5% (goal) Measured 1024 x 1024 Si:As IBC 10 e- @ 7.1 K <0.1 e-/sec @ 7.1 K (test limit) > 50%* > 60%* > 70%* (12 – 24 um) > 30%* (24 – 26 um) > 5%* * QE estimated from AR coat reflectance measurements and QE measurements on non-AR coated detectors See Hoffman, A. et al. poster this conference Test results & analysis reported on this slide provided by Raytheon & their partners. Except where indicated, they have not yet been independently confirmed by NASA/JPL.

22. Raytheon Detector Assembly Design Pedestal Cold Strap Interface Cable SCA Motherboard Attachment Feet 51 Pin Electrical Connector Cover/Baffle Thanks to RVS staff: Roger Holcombe, Rich Mullins, Barbara Ceriale, Margaret Olowski

23. OBA Interface Plane With Locating Pin and Slot Detector Assembly 20mm Thick Al 6061-T6 Back Cover Plate Bonded Fiberglass Thermal Port Al 6061-T6 Cable Closeout Plate Titanium Thermal Strap Support With M6 Bolt M5 Through Holes Focal Plane Module Design Temp Sensor Connector SCA Connector

24. 22 June 2005Scientific Detectors Workshop 2005 Taormina, Sicily 24 Relative Spectral Response Comparisons Test results & analysis reported on this slide provided by Raytheon & their partners. Except where indicated, they have not yet been independently confirmed by NASA/JPL. See Hoffman, A. et al. poster this conference

25. ROIC Read Noise at 7.1 K "Read noise versus Fowler Sampling at 7.1K for ROIC 1-25-C2. The integration time was 25 sec for all Fowler sampled images. Please note that one box was in a region that gave consistently higher noise which is due to excess row-banding in the first 80 rows. There is an occasional second point with higher noise due to cosmic ray hits (which were not filtered out). Therefore, we feel it is valid to ignore the 1-2 points outside the major groupings at each sampling." 10 e- (Fowler-8) 2.5x lower noise than SIRTF/IRAC Test results & analysis reported on this slide provided by Raytheon & their partners. Except where indicated, they have not yet been independently confirmed by NASA/JPL. See Hoffman, A. et al. poster this conference