SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA MIRI VM2 Testing Scott Friedman and the MIRI Test Team (special thanks to Paul Eccleston, Alistair Glasse, Tim Grundy, Gillian Wright)

TIPS – 16 October 2008Friedman 2 of 27 The MIRI Instrument

TIPS – 16 October 2008Friedman 3 of 27 MIRI Capabilities Imaging – = 5–27 microns –1.25  1.88 arcmin field of view –Low resolution spectrograph, R~100, 5-10 microns –Three 4–quadrant phase mask coronagraphs, one Lyot coronagraph Medium resolution spectroscopy – = 5-27 microns (goal is 28.3 microns) –Integral field spectroscopy, 3.5  3.5 arcsec FOV (or more) –R ~ 3000–1000 from = 5–27 microns NASA/JPL partnership with 10 country European Consortium sponsored by ESA NASA provides focal planes and electronics. EC provides optics and bench.

TIPS – 16 October 2008Friedman 4 of 27 MIRI Field of View Medium Resolution Spectrometer MIRI Allocation MIRIM FOV Imager 4QPM 15.5µm 4QPM 11.4µm 4QPM 10.65µm Lyot Mask 23  m Low Resolution Spectrometer

TIPS – 16 October 2008Friedman 5 of 27 Spectral Format of MRS

TIPS – 16 October 2008Friedman 6 of 27 MRS Spectral Bands A B C

TIPS – 16 October 2008Friedman 7 of 27 Some Background Several MIRI models –Structural-thermal model (STM) –Verification model (VM) –Flight model (FM) Delays in MIRI Telescope Simulator (MTS) prompted testing split into two campaigns, VM1 & VM2 VM1 –“MTS-lite” provided point source on imager –Provided testbed for thermal models, scripts, procedures, etc. –Cold testing from 12/17/07 – 1/28/08 VM2 –Instrument cold from 8/16/08 – 10/2/08 –STScI shift support from Burns, Chen, Cracraft, Gordon, Friedman –Script testing by Robinson

TIPS – 16 October 2008Friedman 8 of 27 MIRI Telescope Simulator (MTS) MTS Objective –Deliver a test beam to MIRI similar to output beam of JWST with similar conditions to the flight environment MTS Functionalities –Provide scanning point source across MIRI FOV –Provide extended source covering MIRI FOV –For both point and extended sources Selectable source blackbody temperature and flux level –Provide linearly polarized source –Capability to adjust temperature of one element Background level variation –Provide input pupil sampling by scanning broadband source MTS is an instrument: 150 kg, 8 mechanisms, 4 etalons, WFE < 5  m…

TIPS – 16 October 2008Friedman 9 of 27 MIRI Telescope Simulator (MTS) Built by Instituto Nacianal de Técnica Aerospacial (INTA), Spain

TIPS – 16 October 2008Friedman 10 of 27 MTS Cold Functional Test Summary Heaters all fully operational –Cooldown heaters caused higher background, so heaters off during most of testing –MTS very dark when cold Blackbody source very stable Filter wheel and Variable Aperture Source fully operational Source Scanning and Selection mechanism operational –Point source movable around entire FOV –Point source can be focused only over central region of imager –Point source flux level at MRS is low (~10 electrons/pixel/second at 700K) –Problem with linear stage of extended source - cannot illuminate MRS Pupil scan system fully operational Fold mirror system system almost fully operational –Range of motion limited for 1 of 2 mirrors.

TIPS – 16 October 2008Friedman 11 of 27 VM2 Test Suite IMG_OPT_01 FOV Measurement IMG_OPT_02 PSF Measurement IMG_OPT_03 Pupil Scanning IMG_OPT_04 Opto-Mechanical Stability IMG_OPT_05 Polarization IMG_OPT_06 Out-of-Field Stray Light IMG_RAD_01 Dark Behavior IMG_RAD_02 Nominal Background Behavior IMG_RAD_03 High Background Behavior IMG_RAD_04 Photometric Response To A Point Source IMG_RAD_05 Photometric Response To An Extended Source IMG_RAD_06 Imager Linearity IMG_RAD_07 Spectrophotometric Performance IMG_RAD_08 Photometric Stability IMG_RAD_09 Out of Band Radiation Sensitivity IMG_RAD_10 Imager Readout Modes IMG_RAD_11 Imager Calibrator Setup IMG_RAD_12 Latents IMG_RAD_13 Detector Settling COR_OPT_01 PSF Measurement and Rejection factor COR_OPT_02 Pupil Scanning COR_OPT_03 Opto-Mechanical Stability COR_OPT_04 Coronagraph Polarization COR_OPT_05 Coronagraph Peakup COR_RAD_01 Dark Behavior COR_RAD_02 Nominal Background Behavior COR_RAD_03 Photometric Response to a Point Source and Linearity COR_RAD_04 Spectrophotometric Performance COR_RAD_05 Out Of Band Radiation Sensitivity LRS_OPT_01 FOV Measurement LRS_OPT_02 Polarization LRS_OPT_03 Slit Width LRS_OPT_04 Spectral Resolution LRS_OPT_05 Wavelength Characterization LRS_OPT_06 Wavelength Registration LRS_OPT_07 Wavelength Stability LRS_OPT_08 Source Centering LRS_RAD_01 Dark Behavior LRS_RAD_02 Nominal Background Behavior LRS_RAD_03 Spectrophotometric Performance LRS_RAD_04 Linearity LRS_RAD_05 Photometric Stability LRS_RAD_06 Passband Characterization LRS_RAD_07 Out Of Band Radiation Sensitivity MRS_OPT_01 FOV Measurement MRS_OPT_02 PSF Measurement MRS_OPT_03 Pupil Scanning MRS_OPT_04 Opto-Mechanical Stability MRS_OPT_05 MRS Polarization MRS_OPT_06 Slice Width MRS_OPT_07 Spectral Resolution MRS_OPT_08 Wavelength Characterization MRS_OPT_09 Wavelength Stability MRS_OPT_10 Source Centering MRS_RAD_01 Dark Behavior MRS_RAD_02 Nominal Background Behavior MRS_RAD_03 High Background Behavior MRS_RAD_04 Spectrophotometric Performance MRS_RAD_05 MRS Linearity MRS_RAD_06 Slope Stability MRS_RAD_07 Photometric Stability MRS_RAD_08 Out Of Band Radiation Sensitivity MRS_RAD_09 Passband Characterization MRS_RAD_10 MRS Readout Modes MRS_RAD_11 MRS Calibrator Setup MRS_RAD_12 Latents MRS_RAD_13 Detector Settling

TIPS – 16 October 2008Friedman 12 of 27 Extended Source Slope image 11 micron filter T BB = 300 K T int = 90 sec Excellent flatness (in most regions)

TIPS – 16 October 2008Friedman 13 of 27 Extended Source Flatness 90% of pixels in this region are within 2.8% of median pixel value. Courtesy of Alistair Glasse

TIPS – 16 October 2008Friedman 14 of 27 Opening of Extended Source

TIPS – 16 October 2008Friedman 15 of 27 Point Source MTS Focus Sweep

TIPS – 16 October 2008Friedman 16 of 27 Zemax Ray Trace Model of Point Source Focus Sweep Courtesy of Martyn Wells

TIPS – 16 October 2008Friedman 17 of 27 Region of Sharp Focus

TIPS – 16 October 2008Friedman 18 of 27 Point Source Image from VM1 PSF width and size of Airy ring just as predicted by modeling. Conclusion: the VM is in focus. Problems with VM2 focusing are within the MTS.

TIPS – 16 October 2008Friedman 19 of 27 MRS Internal Flat Field Sub-channel B Slope image 3 dark slices due to intentionally reduced pupils spatial spectral Image Slicer

TIPS – 16 October 2008Friedman 20 of 27 MTS Continuum Point Source on MRS

TIPS – 16 October 2008Friedman 21 of 27 Etalon Point Source on MRS Full frame image Close-up

TIPS – 16 October 2008Friedman 22 of 27 Etalon Point Source on MRS Point source out of focus on MRS FWHM ~ 2.5 pixels Image not flat-fielded Courtesy of Rafael Martinez Galarza

TIPS – 16 October 2008Friedman 23 of 27 Point Source Dark and Background Levels 7 microns CCC openCCC closed

TIPS – 16 October 2008Friedman 24 of 27 Point Source Background Level 25 microns Scattered light from MTS scanning system structure Background much lower than in VM1 due to colder MTS operating temperature

TIPS – 16 October 2008Friedman 25 of 27 Cosmic Rays Cosmic Ray Hits Typical jump electrons

TIPS – 16 October 2008Friedman 26 of 27 Conclusions (directly from Paul Eccleston) Highly sensitive instrument is working properly in a representative environment MTS is largely functioning very well except for point source focus and extended source illumination Test plans mostly working well When VM2 is complete (it is now) we will have thoroughly tested the VM and have met ALL objectives of the test programme.

TIPS – 16 October 2008Friedman 27 of 27 Addendum MIRI operations scripts –Controlled 4 mechanisms Imager filter wheel Both MRS grating/dichroic wheels Contamination control cover –Run on warm VM by M. Robinson on 10/13/08 –All scripts ran to completion. No errors of any kind generated. VM scheduled to be brought up to air today.