Coronagraphy withtheWFIRSTAperture
N.JeremyKasdin
Whatmakesitchallenging?
−0.5 0 0.5−0.5
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y(λ
/D)
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−15
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TheAFTAPupil TheAFTAPSF
Sayanythingabouthowthispupilmakesgettingsmallinnerworkinganglehard?
Coronagraphselectionbasedonmaturity,robustness,flexibility
PupilMasking(Kasdin, PrincetonUniversity)
PupilMapping(Guyon,Univ.Arizona)
ImagePlanePhaseMask(Serabyn,JPL)
ImagePlaneAmplitude&PhaseMask(Trauger,JPL)
VisibleNuller – PhaseOcculting(Clampin, NASAGSFC)VisibleNulller - DAVINCI(Shao, JPL)
HLCSPC
VVC VNC-POVNC - DAVINCI
PIAACMC
04/30/2014 WFIRST-AFTASDTInterimReport 3
ApproachtoRecommendation• Objective:Recommendaprimary andbackup coronagrapharchitecturetofocusdesignandtechnologydevelopmentleadingtopotentialnewmissionstartinF17
• RecommendationbyExEPOandASObasedoninputsfrom• SDT:Setsthesciencerequirements• ACWG:DeliverstechnicalFOMsandtechnologyplans
>Aimforthepositive:aconsensusproduct>SDTdeliversscienceFOMs
• TAC:AnalysisoftechnicalFOM,TRLreadinessplans,andrisks
• ExEPOandASOrecommendationtoAPDDirectorbasedon:
• TechnicalandProgrammatic• Musts(Requirements),Wants(Goals),andRisks• Distinguishdescriptionfromevaluation
• APDDirectorwillmakethedecision
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ACWG=representativesofExEPO,ASO,SDT,Community
Howdowedefineasuccessfuloutcome?
FOM=FigureofMerit
TAC:AlanBoss(CarnegieMellon)JoePitman(EXSCI)SteveRidgway(NOAO)LisaPoyneer (LLNL)BenOppenheimer(AMNH)
ACWGMembership• TheserepresentProgram,StudyOffice,SDT,andCommunity:
• AdditionalconsultantsparticipateatrequestofSteeringGroup
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Members:JeremyKasdin (PrincetonU)MarkMarley(NASAARC)MarcClampin (NASAGSFC)OlivierGuyon(UofA)GeneSerabyn (NASAJPL)StuartShaklan(NASAJPL)RemiSoummer(STScI)JohnTrauger (NASAJPL)MarshallPerrin(STScI)RickLyon(NASAGSFC)DaveContent(NASAGSFC)MarkMelton(NASAGSFC)CliffJackson(NASAGSFC)JohnRuffa (NASAGSFC)JenniferDooley(NASAJPL)MikeShao(NASAJPL)
Steering Group:GaryBlackwood(NASAJPL)KevinGrady(NASAGSFC)FengZhao(NASAJPL)PeterLawson(NASAJPL)ScottGaudi(OSU)NeilGehrels (NASAGSFC)DaveSpergel (PrincetonU)TomGreene(NASAARC)ChasBeichman(NExScI)JeffKruk(NASAGSFC)KarlStapelfeldt (NASAGSFC)WesTraub(NASAJPL)BruceMacIntosh(LLNL)
Charter
RecommendationCriteria:DefiningaSuccessfulOutcomeMUSTS(Requirements):Go/No_Go1. Science:Doestheproposedarchitecturemeetthebaseline sciencedrivers?2. Interfaces:Forthebaseline science,doesthearchitecturemeettelescopeandspacecraftrequirementsofthe
observatoryasspecifiedbytheAFTAproject(DCIL1)3. TechnologyReadinessLevel(TRL)Gates:Forbaseline science,isthereacredibleplantobeatTRL5atthestart
ofFY17andatTRL6atthestartofFY19withinavailableresources?4. Istheoptionreadyintimeforthisselectionprocess?
WANTS(Goals):Relativetoeachother,forthosethatpasstheMusts:1. Science:Relativestrengthofsciencebeyondthebaseline2. Technical:Relativetechnicalcriteria
- Seedetails3. Programmatic:RelativecostofplantomeetTRLGates
RISKSandOPPORTUNITIES- Seedetails
61DCL=DaveContentInterfaceList
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Hybrid Lyot Coronagraph
Baseline design for WFIRST/AFTA
From John Trauger, JPLTotalPSFcorethroughput =4.5%
Transmission=48%
No jitter0 mas
star
0.4 mas jitter1.0 mas star
0.8 mas jitter1.0 mas star
1.6 mas jitter1.0 mas star
HLC
SPC
PIAACMC
WFIRST Dark Holes with Pointing Jitter & Finite Star
WFIRST PIAACMC uses a single DM forsimplicity, so it has asingle-sided dark hole
r = 9 λ/D
Coronagraphsimulationsusevalidatedwave-opticscode
AFTAPupil Shaped Pupil Focal plane mask
r = 2.5 – 9 λ /Dc65° opening angle
27% mask transmission
Lyot stop
r = 0.3 – 0.9 rsp pup
TotalPSFcorethroughput =3.7%
Simulationsshowe.g.robustperformanceagainstjitter
1.6 mas RMS jitter0.8 mas RMS jitter0.4 mas RMS jitter No jitter
728– 872nmJitterlevelsshownhereareaftercoronagraphfasttip/tilt
SimulationsshowstablehighcontrastwithAFTAinthermalscenarios
• ProperEFCcorrectionfortelescopenominalwavefront(initialDMsetting)• Gen1SPCdesign,10%bandwidth, l=550nm,3.9~12.3l/DWA,56deg openingangle• RealisticAFTAsurfaceaberration(amplitude+phase),and• Piston/tip/tilt/focus correctioncomputedonlyonce initially• Thesystemconfigurationisheldconstantthroughouttheobservations
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Rawspeckle,S(t) ΔSpeckle (rel.tonominal):S(t)– S(0)
TypicalMeanContrast:~5.3e-9 TypicalMeanΔ Contrast:~4.4e-11
PIAA- CMC
DM1,DM2 Pupilmapping Apodizer mask Occultingmask Lyot stop Inversepupilmapping
MediumACADonbothDMs
PIAAmirrors Grayscale,filerwheels?
Phasetransmission,onfilterwheel
Transmission,binary,fixed?
InversePIAAmirrors
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FPA
ToLOWFSPIAAmirrors
InversePIAA
DM1/FSM
DM2
Finaldesigndeadlineextendedto11/4/2013
13December8-9,2015
CGIOperationalModes
Pupilmask
Lyotmask
Filterwheel
Fieldstopmask
toLOWFS
FSM
PBS
M4
M3
CORF1
R3OAP1
R3OAP2
COLF1
COLF2
FSOAP1
FSOAP2
Tertiary Collimator Assembly (TCA)
Coronagraph Instrument (CGI)
DM2
FocMR1OAP1
R1OAP2
R2OAP1
R2OAP2
DM1
FM
IFS/ImgSelector
FocalPlanemask
RadiationShieldMirror
FPA
Telescope
T1
T2
CORF2
IMG
HybridLyot ModeImagingin2simultaneouspolarizations,simulatedplanetsarecircledinred
14December8-9,2015
CGIOperationalModes
R3OAP1
TelescopeT2
Pupilmask
Lyotmask
Filterwheel
Fieldstopmask
FSM
M4
M3
CORF2
R3OAP1
R3OAP2
COLF1
COLF2
FSOAP1
FSOAP2
DM2
FocMR1OAP1
R1OAP2
R2OAP1
R2OAP2
DM1
FM
IFS/ImgSelectorFocalPlane
mask
T1
ShapedPupilSpectroscopyMode
FPA
IFS
IFS
CORF1
toLOWFS
TheIFSuses318%bandstoproduceanR=70spectrafrom600to970nm
lensletarray pinhole
maskdispersed
lenslet images
extracted datacube
SPCimagesin318%bands
Tertiary Collimator Assembly (TCA)
Coronagraph Instrument (CGI)
BackupSlides
Starlightsuppression-- TechnicalApproach
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Primaryapproach
Back-upapproach
Downselect1/6/2014
TRL-5@startofPhaseA(10/2016) TRL-6@PDR(10/2018)
VisibleNuller Coronagraph:Phase-Occulting(Lyon,GSFC)
VisibleNuller Coronagraph:DaVinci (Shao,JPL)
Sixdifferentconcepts
HybridLyot
DM1,DM2 Pupilmapping Apodizer mask Occultingmask Lyot stop Inversepupilmapping
MildACADonboth DMs
Complextransmission,onfilterwheel
Transmission,grey,fixed
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FPA
DM1/FSM
DM2
ToLOWFS
ShapedPupil
DM1,DM2 Pupilmapping Apodizer mask Focalplanemask Lyot stop Inversepupilmapping
MildACADonbothDMs
Binaryreflectiononfilterwheels
Binarytransmission,onfilterwheel
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FPA
ToLOWFS
DM1/FSM
DM2
VectorVortex
DM1,DM2 Pupilmapping Apodizer mask Focalplanemask Lyot stop Inversepupilmapping
Strong ACADonbothDMs
Binarytransmission, onfilterwheel
Vortextransmission,onfilterwheel
Transmission,binary,fixed
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FPA
ToLOWFS?
DM1/FSM
DM2
PIAA- CMC
DM1,DM2 Pupilmapping Apodizer mask Occultingmask Lyot stop Inversepupilmapping
MediumACADonbothDMs
PIAAmirrors Grayscale,filerwheels?
Phasetransmission,onfilterwheel
Transmission,binary,fixed?
InversePIAAmirrors
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FPA
ToLOWFSPIAAmirrors
InversePIAA
DM1/FSM
DM2
Finaldesigndeadlineextendedto11/4/2013
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FromAFTATelescope
APSClock90°
AFTAExitPupilVNCEntrancePupil
BS
ToScienceToWFC
GregorianRelayw/POOptics
BS9.5mmfused silica
AFTA:Phase-OccultedVNCNullingSchematic
Interferometer WFC
1stagenullinginterferometer TwoDMsforbothphaseandamp
Fullaperture(radialshear) Lyot stop?
Achromaticphaseshifters*
DelaylinetoadjustOPD
VNC-DaVinci
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Interferometer WFC
2stagenullinginterferometers OneDM(4quadrants)forbothphaseandamplitudecontrol
Dilutedaperture(4X) Lyot stopmask(binary,transmission,fixed)
Achromaticphaseshifters Fiberbundlespatial filters
Delay linetoadjustOPD
FPA
p
p 00
p
p 00
DM
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