MIRI VM2 Testing

Scott Friedmanandthe MIRI Test Team(special thanks to Paul Eccleston, Alistair Glasse,Tim Grundy, Gillian Wright)

The MIRI Instrument

MIRI CapabilitiesImaging = 527 microns1.25 1.88 arcmin field of viewLow resolution spectrograph, R~100, 5-10 micronsThree 4quadrant 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 ~ 30001000 from = 527 microns

NASA/JPL partnership with 10 country European Consortium sponsored by ESANASA provides focal planes and electronics. EC provides optics and bench.

MIRI Field of View

Spectral Format of MRS

MRS Spectral BandsABC

Some BackgroundSeveral MIRI modelsStructural-thermal model (STM)Verification model (VM)Flight model (FM)Delays in MIRI Telescope Simulator (MTS) prompted testing split into two campaigns, VM1 & VM2VM1MTS-lite provided point source on imagerProvided testbed for thermal models, scripts, procedures, etc.Cold testing from 12/17/07 1/28/08VM2Instrument cold from 8/16/08 10/2/08STScI shift support from Burns, Chen, Cracraft, Gordon, FriedmanScript testing by Robinson

MIRI Telescope Simulator (MTS)MTS ObjectiveDeliver a test beam to MIRI similar to output beam of JWST with similar conditions to the flight environmentMTS FunctionalitiesProvide scanning point source across MIRI FOVProvide extended source covering MIRI FOVFor both point and extended sourcesSelectable source blackbody temperature and flux levelProvide linearly polarized sourceCapability to adjust temperature of one elementBackground level variationProvide input pupil sampling by scanning broadband sourceMTS is an instrument: 150 kg, 8 mechanisms, 4 etalons, WFE < /20 @ 5 m

MIRI Telescope Simulator (MTS)Built by Instituto Nacianal de Tcnica Aerospacial (INTA), Spain

MTS Cold Functional Test SummaryHeaters all fully operationalCooldown heaters caused higher background, so heaters off during most of testingMTS very dark when coldBlackbody source very stableFilter wheel and Variable Aperture Source fully operationalSource Scanning and Selection mechanism operationalPoint source movable around entire FOVPoint source can be focused only over central region of imagerPoint source flux level at MRS is low (~10 electrons/pixel/second at 700K)Problem with linear stage of extended source - cannot illuminate MRSPupil scan system fully operationalFold mirror system system almost fully operationalRange of motion limited for 1 of 2 mirrors.

VM2 Test SuiteIMG_OPT_01 FOV MeasurementIMG_OPT_02 PSF MeasurementIMG_OPT_03 Pupil ScanningIMG_OPT_04 Opto-Mechanical StabilityIMG_OPT_05 PolarizationIMG_OPT_06 Out-of-Field Stray Light

IMG_RAD_01 Dark BehaviorIMG_RAD_02 Nominal Background BehaviorIMG_RAD_03 High Background BehaviorIMG_RAD_04 Photometric Response To A Point SourceIMG_RAD_05 Photometric Response To An Extended SourceIMG_RAD_06 Imager LinearityIMG_RAD_07 Spectrophotometric PerformanceIMG_RAD_08 Photometric StabilityIMG_RAD_09 Out of Band Radiation SensitivityIMG_RAD_10 Imager Readout ModesIMG_RAD_11 Imager Calibrator SetupIMG_RAD_12 LatentsIMG_RAD_13 Detector Settling

COR_OPT_01 PSF Measurement and Rejection factorCOR_OPT_02 Pupil ScanningCOR_OPT_03 Opto-Mechanical StabilityCOR_OPT_04 Coronagraph PolarizationCOR_OPT_05 Coronagraph Peakup

COR_RAD_01 Dark BehaviorCOR_RAD_02 Nominal Background BehaviorCOR_RAD_03 Photometric Response to a Point Source and LinearityCOR_RAD_04 Spectrophotometric PerformanceCOR_RAD_05 Out Of Band Radiation Sensitivity

LRS_OPT_01 FOV MeasurementLRS_OPT_02 PolarizationLRS_OPT_03 Slit WidthLRS_OPT_04 Spectral ResolutionLRS_OPT_05 Wavelength CharacterizationLRS_OPT_06 Wavelength RegistrationLRS_OPT_07 Wavelength StabilityLRS_OPT_08 Source Centering

LRS_RAD_01 Dark BehaviorLRS_RAD_02 Nominal Background BehaviorLRS_RAD_03 Spectrophotometric PerformanceLRS_RAD_04 LinearityLRS_RAD_05 Photometric StabilityLRS_RAD_06 Passband CharacterizationLRS_RAD_07 Out Of Band Radiation Sensitivity

MRS_OPT_01 FOV MeasurementMRS_OPT_02 PSF MeasurementMRS_OPT_03 Pupil ScanningMRS_OPT_04 Opto-Mechanical StabilityMRS_OPT_05 MRS PolarizationMRS_OPT_06 Slice WidthMRS_OPT_07 Spectral ResolutionMRS_OPT_08 Wavelength CharacterizationMRS_OPT_09 Wavelength StabilityMRS_OPT_10 Source Centering

MRS_RAD_01 Dark BehaviorMRS_RAD_02 Nominal Background BehaviorMRS_RAD_03 High Background BehaviorMRS_RAD_04 Spectrophotometric PerformanceMRS_RAD_05 MRS LinearityMRS_RAD_06 Slope StabilityMRS_RAD_07 Photometric StabilityMRS_RAD_08 Out Of Band Radiation SensitivityMRS_RAD_09 Passband CharacterizationMRS_RAD_10 MRS Readout ModesMRS_RAD_11 MRS Calibrator SetupMRS_RAD_12 LatentsMRS_RAD_13 Detector Settling

Extended SourceSlope image11 micron filterTBB = 300 KTint = 90 secExcellent flatness (in most regions)

Extended Source Flatness90% of pixels in this region are within 2.8% of median pixel value.Courtesy of Alistair Glasse

Opening of Extended Source

Point Source MTS Focus Sweep

Zemax Ray Trace Model ofPoint Source Focus SweepCourtesy of Martyn Wells

Region of Sharp Focus

Point Source Image from VM1PSF 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.

MRS Internal Flat Field Sub-channel B Slope image 3 dark slices due to intentionally reduced pupilsspatialspectralImage Slicer

MTS Continuum Point Source on MRS

Etalon Point Source on MRSFull frame imageClose-up

Etalon Point Source on MRS Point source out of focus on MRS FWHM ~ 2.5 pixels Image not flat-fieldedCourtesy ofRafael Martinez Galarza

Point Source Dark and Background Levels 7 micronsCCC openCCC closed

Point Source Background Level25 microns Scattered light from MTS scanning system structure

Background much lower than in VM1 due to colder MTS operating temperature

Cosmic RaysCosmic Ray HitsTypical jump 500 - 3000 electrons

Conclusions (directly from Paul Eccleston)Highly sensitive instrument is working properly in a representative environmentMTS is largely functioning very well except for point source focus and extended source illuminationTest 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.

AddendumMIRI operations scriptsControlled 4 mechanismsImager filter wheelBoth MRS grating/dichroic wheelsContamination control coverRun on warm VM by M. Robinson on 10/13/08All scripts ran to completion. No errors of any kind generated.

VM scheduled to be brought up to air today.

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