The James Webb Space Telescope its Infrared Detectors

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 Jet Propulsion Laboratory 2 NASA 22 22 June 2005 Scientific Detectors Workshop Scientific Workshop 2005 Taormina, Sicily 1 1

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

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. 22 June 2005 • JWST’s near and mid-IR wavelengths offer a very different perspective on the Universe compared to optical! Spiral galaxy M 81 seen in: (1) optical/Kitt Peak and , (2) 3. 6 mm, (3) 8 mm, and 24 mm and (d) composite Spitzer images. Scientific Detectors Workshop 2005 Taormina, Sicily 3

Top JWST Goal - Find the First Light after the Big Bang ����� ���as seen by COBE ? Galaxy assembly ? Galaxies, stars, planets, life • 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)

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

James Webb Space Telescope (JWST) § 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. 5 m diameter segmented adjustable primary mirror – Cryogenic temperature telescope and instruments for infrared performance – Launch in 2012 to Sun-Earth L 2 – 5 -year science mission (10 -year goal) www. JWST. nasa. gov today Concept Development 22 June 2005 mission formulation authorized Design, Fabrication, Assembly and Test Scientific Detectors Workshop 2005 confirmation for Sicily Taormina, mission implementation . . . science operations launch 6

22 June 2005 Scientific Detectors Workshop 2005 Taormina, Sicily 7

Instrument Overview 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 (2048 x 2048) 68 mas pixels • John Hutchings, lead Near Infra-Red Camera (NIRCam) • Detects first light galaxies and observes galaxy assembly sequence • 0. 6 to 5 microns, 2 (4096 x 4096) 31 mas pixels & 2 (2048 x 2048) 62 mas 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 Mid-Infra-Red Instrument (MIRI) • 0. 6 to 5 microns • Distinguishes first light objects; studies galaxy • Simultaneous spectra of >100 objects evolution; explores protostars & their environs • 2 (2048 x 2048) 100 mas pixels Former location • Imaging 1 (1024 x 1024) 110 mas pixels of dewar • Resolving powers of ~100, ~1000, ~3000 • Spectroscopy (R~3000) 2 (1024 x 1024) 200 ESA/Astrium provided, with NASA 10 22 pixels June 2005 Scientific Detectors Workshop • 2005 470 mas Detectors & Microshutter Taormina, Sicily • 5 to 27 microns; Cooled to 7 K by cryocooler

Infrared Detectors for JWST • Rockwell Scientific selected for NIRCam, NIRSpec and possibly FGS – Total of 19 Hawaii-2 RG 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 22 June 2005 Scientific Detectors Workshop 2005 Taormina, Sicily 11

Near-Infrared Detector Technology Development l NICMOS and IRAC arrays demonstrated the basic detector architecture but with lower performance and smaller formats. l. TRL 4 achieved Feb 2002 with JWST performance levels achieved l TRL 5 achieved Feb 2003 with JWST size 2 Kx 2 K devices, mosaicing l Astronomical Image with prototype, Sept. 2003 Hg. Cd. Te NICMOS 256 x 256 22 June 2005 WFC 3 1024 x 1024 JWST Proto-type 4 Kx 4 K Scientific Detectors Workshop 2005 Taormina, Sicily 12

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

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 22 June 2005 Scientific Detectors Workshop 2005 Taormina, Sicily 14

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 mm cutoff SCA – SCA to ASIC electrical interfaces – ASIC Total Noise per 1000 s The above figure was presented by Rockwell Scientific as part of an ASIC review package. Test data and analysis are by Rockwell staff. Baseline NIRSpec mode shown in Red. Uses 88 non-destructive samples up t~1000 s ramp. *For the data that were provided, we found that we needed one additional calibration step compared to Rockwell. The 22 additional step was similar to correcting a small pedestal drift. 2005 It was needed because the reference 15 June 2005 Scientificfor Detectors Workshop pixels did not perfectly track the regular pixels. Taormina, Sicily

SIDECAR ASIC Exceeds JWST Noise Requirements • SIDECAR ASIC has demonstrated excellent noise performance that exceeds the requirements for all three near-infrared instruments (37 K SWIR H 2 RG + ASIC) Noise at low bias 1 Noise at medium bias 1 2. 0 e- 1. 8 e- 16. 5 e- 16. 2 e-3 ASIC + HAWAII-2 RG Fowler 8 -8 6. 8 e- 6. 7 e- 9 e(NIRCAM) ASIC + HAWAII-2 RG (4 – 22 multiaccum) 5. 3 e- 5. 2 e-2, 3 6 e(NIRSpec) ASIC by itself (NIRSpec 4 -22 multiaccum) ASIC + HAWAII-2 RG CDS 1100 JWST Requirement 2. 4 e (NIRSpec) 24 e(extrapolated) k. Hz pixel rate MULTIACCUM-22 x 4 calculated using 4 out of 6 measured ramps due to larger frameto-frame pedestal in remaining 2 ramps. 2 3 Analysis of test data independently confirmed by NASA/GSFC 22 June 2005 Test results & analysis reported on this slide provided by Scientific Detectors Workshopthey 2005 Rockwell Scientific. Except where indicated, have not yet been independently confirmed by NASA/GSFC. Taormina, Sicily 16

Near-Infrared Dark Current Tests Have Achieved the Required Levels Engineering Unit JWST-009, substrate removed SWIR array, dark current histogram and map 22 June 2005 Test results & analysis reported on this slide provided by Scientific Detectors Workshop 2005 Test results reported on this slide Rockwell Scientific. Except where indicated, they have not yet provided. Taormina, by confirmed Rockwell Scientific been independently by NASA/GSFC. Sicily 17

Visible QE Exceeds 80% at 800 nm Engineering Unit JWST-009, substrate removed SWIR array, QE histogram and map at 800 nm - illumination nonuniformity not removed 22 June 2005 Test results & analysis reported on this slide provided by Scientific Detectors Workshop 2005 Test results reported on this slide Rockwell Scientific. Except where indicated, they have not yet provided. Taormina, by confirmed Rockwell Scientific been independently by NASA/GSFC. Sicily 18

Longer Wavlength QE Exceeds 80% As Expected Engineering Unit JWST-009, substrate removed SWIR array, QE histogram and map at 1230 nm - illumination nonuniformity not removed Test results & analysis reported on this slide provided by 22 June 2005 Scientific Detectors Workshop 2005 Test results reported on this slide Rockwell Scientific. Except where indicated, they have not yet provided. Taormina, by confirmed Rockwell Scientific been independently by NASA/GSFC. Sicily 19

Mid-Infrared Technology Development • Concept studies for a JWST mid-IR instrument begun in 1997 • Tentative detector requirements laid out in these studies • Craig Mc. Creight 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 22 June 2005 Scientific Detectors Workshop 2005 Taormina, Sicily 20

MIRI Focal Plane Primary Requirements Parameter Format Requirement Measured 1024 x 1024 Si: As IBC Detector Material Noise (Fowler-8 sampling) < 19 e- @ 7. 1 K 10 e- @ 7. 1 K Dark Current < 0. 03 e-/sec @ 7. 1 K QE: 5 – 6 um 6 – 12 um 12 – 26 um > 40% > 60% > 70% 26 – 28. 2 um > 5% (goal) <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 22 June 2005 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. Scientific Detectors Workshop 2005 Taormina, Sicily 21

Raytheon Detector Assembly Design Cover/Baffle SCA Attachment Feet 51 Pin Electrical Connector Motherboard Cable Pedestal Thanks to RVS staff: Roger Holcombe, Rich Mullins, Ceriale, Margaret 22 June. Barbara 2005 Scientific Olowski Detectors Workshop 2005 Taormina, Sicily Cold Strap Interface 22

Focal Plane Module Design M 5 Through Holes 20 mm Thick Al 6061 -T 6 Back Cover Plate Detector Assembly Temp Sensor Connector SCA Connector OBA Interface Plane With Locating Pin and Slot 22 June 2005 Titanium Thermal Strap Support With M 6 Bolt Bonded Fiberglass Thermal Port Scientific Detectors Workshop 2005 Taormina, Sicily Al 6061 -T 6 Cable Closeout Plate 23

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 22 June 2005 Scientific Detectors Workshop 2005 Taormina, Sicily 24

ROIC Read Noise at 7. 1 K "Read noise versus Fowler Sampling at 7. 1 K for ROIC 1 -25 -C 2. 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. 5 x 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. 22 June 2005 Scientific Detectors Workshop 2005 Taormina, Sicily 25 See Hoffman, A. et al. poster this conference