The High Definition X-ray Imager (HDXI) of the Lynx X-Ray Surveyor Mission
Abe Falcone (Penn State University) RalphKraft(SAO),MarkBautz(MIT),JessicaGaskin(MSFC),JohnMulqueen(MSFC)DougSwartz(MSFC) on behalf of the Lynx Science & Technology Definition Team
Using X-ray eyes, Lynx will peer deeply into the origin and evolution of structure in the Universe
S. Allen, StanfordM. Bautz, MITW. N. Brandt, Penn StateJ. Bregman, MichiganM. Donahue, MSUJ. Gaskin, MSFC (Study Sci.)Z. Haiman, ColumbiaR. Hickox, DartmouthT. Jeltema, UCSC
J. Kollmeier, OCIWA. Kravtsov, U. ChicagoL. Lopez, Ohio StateR. Osten, STScIF. Paerels, ColumbiaD. Pooley, TrinityA. Ptak, GSFCE. Quataert, BerkeleyC. Reynolds, UMDD. Stern, JPL
Community STDTF. Özel, Arizona (Co-Chair)A. Vikhlinin, SAO (Co-Chair)
Lynx Concept Team
+InstrumentsWorkingGroups:MarkBautz(Chair)HDXICo-Chairs:AbeFalcone,RalphKraftuCalCo-Chairs:SimonBandler,EnactaliFigueroa-FelicianoGratingCo-Chairs:RandyMcEntaffer,RalfHeilmann+OpticsWorkingGroup:Co-Chairs:MarkSchattenberg,LesterCohen+8ScienceWorkingGroups
F. Özel, Arizona (Co-Chair)A. Vikhlinin, SAO (Co-Chair)
S. Allen, StanfordM. Bautz, MITW. N. Brandt, Penn StateJ. Bregman, MichiganM. Donahue, MSUJ. Gaskin, MSFC (Study Sci.)Z. Haiman, ColumbiaR. Hickox, DartmouthT. Jeltema, UCSC
J. Kollmeier, OCIWA. Kravtsov, U. ChicagoL. Lopez, Ohio StateR. Osten, STScIF. Paerels, ColumbiaD. Pooley, TrinityA. Ptak, GSFCE. Quataert, BerkeleyC. Reynolds, UMDD. Stern, JPL
Thereare>250peopleacrossacademia,industry,government,andnon-USspaceagenciesinvolvedintheLynxConceptStudy
Meet Lynx!
LynxwillprovideunprecedentedX-rayvisionintothe“Invisible”UniversewithleapsincapabilityoverChandraandATHENA: 50–100×gaininsensitivityviahighthroughputwithhighangularresolution
16×fieldofviewforarcsecondorbetterimaging
10–20×higherspectralresolutionforpoint-likeandextendedsources
×800highersurveyspeedattheChandraDeepFieldlimit
Oneof4largemissionsunderstudyforthe2020AstrophysicsDecadal,LynxisanX-rayobservatorythatwilldirectlyobservethedawnof
supermassiveblackholes,revealtheinvisibledriversofgalaxyandstructureformation,andtracetheenergeticsideofstellarevolutionand
stellarecosystems.
Lynxwillcontributetonearlyeveryareaofastrophysicsandprovidesynergisticobservationswithfuture-generationground-basedandspace-basedobservatories.
Unique parameter space of Lynx combining superb angular resolution with large area and excellent spectroscopy
The Dawn of Black Holes Lynxwillobservethebirthofthefirstseedblackholesatredshiftupto10andprovideacensusofthemassiveblackholepopulationinthelocalanddistantuniverse,followtheirgrowthandassemblyacrosscosmictime,andmeasuretheimpactoftheirenergyinputonallscales.
Simulated2x2arcmindeepfieldsJWST,~0.1” resolution,‘First Galaxies’
4 Msec, 5″ resolutionConfusion Limited
Lynx (4 Msec), 0.5” resolution‘First Accretion Light’
Invisible Drivers Behind Galaxy Formation and Evolution Theassembly,growth,andstateofvisiblematterinthecosmicstructuresislargelydrivenbyviolentprocessesthatheatthegasintheCGMandIGM.TheexquisitespectralandangularresolutionofLynxwillmakeitauniqueinstrumentformappingthehotgasaroundgalaxiesandintheCosmicWeb.
Facility Class Observatory: Exploration Science with a Rich Community-Driven General Observer Program!
JWSTwilldetect~2×106gal/deg2atitssensitivitylimit(Windhorstetal.).The<0.5”angularresolutionofLynxwillminimizesourceconfusionforX-raydetectedSMBHs.
Energetic Side of Stellar Evolution and Stellar Ecosystems Lynxwillstudytheendpointsofstellarevolution,stellarbirth,coronalstructure,andtheimpactsoffeedback.StellarX-rayvariabilitymeasurementswillenabledeterminationoftheimpactofstellaractivityonthehabitabilityofplanets.
seeLynxoverviewformoredetail(Gaskinetal.,theseproceedings)
Lynx Configuration
X-ray grating (deployable)
Translation Table
Optical Bench
Optics
Pre-Collim
ator
Post-Collim
ator Fo
cal P
lane
10 m 2.3 m
3 m
4.3 m
Science Instrument Module X-ray Grating Spectrometer Readout High-Definition X-ray Imager Lynx X-ray Micro-calorimeter
Credit:MSFCACO
Lynx Science Instruments
X-Ray Grating Spectrometer (XGS) XGSLeads:R.McEntaffer(PSU),RalfHeilmann(MIT)
InstrumentDesignStudy(On-going@MSFCACO)
HDXILeads:R.Kraft(SAO),A.Falcone(PSU)
InstrumentDesignStudy(On-going@MSFCACO)
Lynx X-ray Microcalorimeter (LXM) LXMLeads:S.Bandler(GSFC),E.Figueroa-Feliciano(Northwestern)
InstrumentDesignLab(Completed1stIDL@GSFC)
MonolithicCMOS HybridCMOS DigitalCCDwithCMOSreadout
Off-PlaneGratingArray CriticalAngleTransmissionGratingArray
LynxX-rayMicrocalorimeter
Instrument Working Group Lead: M. Bautz (MIT)
Science Instrument Accommodation Looking forward from below ISIM Looking aft from mirror
Translation table (gray) positions either LXM or HDXI at focus XGS readout mounted on stationary bench (blue) 4 observing configurations: (HDXI or LXM) x (w/ or w/o grating in beam)
HDXI µCalorimeter
OPG
HDXI
.635 m 2.5 m
2.5 m
XGS readout
LXM
Table Motion
Credit:MSFCACO
HDXI Performance requirements and goals HDXI Parameter Requirement Science Drivers
Energy Range 0.2 – 10 keV Sensitivity to high-z sources
Field of view 22 x 22 arcmin Deep Survey efficiency R200 for nearby galaxies
Pixel size 16 x 16 µm Pt. source sensitivity Resolve AGN from group emission
Read noise ≤ 4 e- Low-energy detection efficiency
Energy Resolution (FWHM)
70 eV @ 0.3 keV 150 eV @ 5.9 keV
Low-energy detection efficiency
Full-field count-rate capability 8000 ct s-1
No dead time for bright diffuse sources (e.g. Perseus or Cas A)
Frame Rate Full-field Window mode (20”x20”)
> 100 frames s-1
> 10000 windows s-1
Maximize low-energy throughput Minimize background
High Definition X-ray Imager (HDXI) High Definition X-ray Imager (Notional Requirements) EnergyRange 0.2–10keV
QE(includingfilter) >0.85at0.5-7keV,>TBDfrom0.15-0.5keV
FOV 22’x22’(4kx4kpixels)
PixelSize 16x16µm(≤0.33”)
ReadNoise ≤4e-
EnergyResolution ≤[email protected],≤[email protected](FWHM)
FrameRate >100frames/s(fullframe)>10000frames/s(windowedregion)
RadiationTolerance 10yrsatL2
detector focal plane layout : 21 tilted detectors with 1024x1024 pixels (≤16 µm pixel pitch) per detector.
Notional HDXI Instrument Configuration
SensorArray(21 Sensors)
Filter Assembly(4 filters)
VacuumEnclosure Door
Pedestal
Me2.1
Me1
Translation Table
SARH
FEMB
SensorAssembly
SensorElectronics0Unit
Heaters
Spacecraft)Bus
LVDSPower
SW
Heat@Pipe
Heat@Pipe
Radiators
DEU Cold Plate
GSE Vacuum ValveContamination
Vent TubeMe3
Flexure Mounts
Me2.2
PedestalMosaic Plate
Sensor Baseplate
Indium Seals
Indium Seal
O-ring
Sensor Top Plate
Sensor Housing
Filter Assembly Housing
Me1 Mount
Me2 Mount
DS
DEUS
CS
Back0End0Processor0(2)Filter0Mechanism0Drive0Board0(2)0Heater0Control0&0HK Board0(2)
Event Recognition Processor (5)
Power0Supply0Board0(2)
PCI0backplane
Coolant Line
BlockDiagram DetectorHousingConcept
Resources
Power(W) 175
Mass(kg)DetectorAssyElectronicsDataRate
483612
<600kBytes/s
Detectorarray211kx1kSisensors
FilterAssembly(includescal.source)
Door&actuator
Credit:GSFCIDL
High Definition X-ray Imager (HDXI)
FEMBHDXI)DetectorsSpacecraft)Bus
C&DH%Subsystem
Detector%Electronics%Unit(DEU)
Electrical%Power%Subsystem
1pps,%(A/B)
Survival%Heaters%(n) Survival%Power
FEMB%/%ASIC%Control
Mechanism%control
Data%Time%Stamp
Data%Packetization
Temperature%Control
H/K%Data%Collection
Data%Buffering
Power%Conversion%
SpaceWire,%%(A/B)
1553/RS422,%(A/B)Detector%Arrays21(1K%x%1K)pix
bias
Analog%(21)
control,%clocks
LVDS
SIDECAR%ASICS(21)
(control,%clocks)
+28V%Power%(A/B)
SSR
TelecomSubsystem
Uplink/Downlink
Thermal)Subsystem
analog
power
MechanismsFilter%Select%Motor%(1A/1B) Motor%Drive%Current%(analog)
Power%(switched)
PID%Control%Heaters%(2A/2B)power%(on/off)Filter%Heaters%(4A/4B)
+28V%(on/off)DeJContamination%Heaters%(2A/2B)
Temperature%Sensors%(n)
Filter%Override%Motor%(1A/1B)
Vacuum%Door%Motor%(1A/1B)
Vent%Valve%Solenoid%(1A/1B) Solenoid%Drive%Current%(analog)
MicroJSwitches%(12A/12B) Position%feedback%(biRlevel)
Motor%Drive%Current%(analog)
Motor%Drive%Current%(analog)
HallJEffect%Sensors%(4A/4B) Position%feedback%(analog)
Electronics&Interfaces
3 Different HDXI Sensors Approaches MonolithicCMOSActivePixelSensor
SingleSiwaferusedforbothphotondetectionandreadoutelectronics Sarnoff/SAOandMPE(seeKraftetal.)
HybridCMOSActivePixelSensor Multiplebondedlayers,withdetectionlayeroptimizedforphotondetectionandreadoutcircuitrylayeroptimizedindependently Teledyne/PSU(seeHull,S.etal.,theseproceedings)
DigitalCCDwithCMOSreadout CCDSisensorwithmultipleparallelreadoutportsanddigitizationon-chip LL/MIT(seeBautz,M.etal,theseproceedings)
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Teledyne
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Swift/XRT
Sarnoff
22 mm
512 x 512 8µm pixel
CCID85A B C
D E F
Current State of the Art Eachofthesensortechnologiespresentlymeetssomeoftheexpectedrequirements.
Nosinglesensormeetsthemall–>worktodobetweennowandphaseAandduringphaseA.
Keysensortrade-offs1) Pixelsize
SmallpixelsizedesiredtooversamplePSF.However,thisdecreasesenergyresolution–requiresbetternoiseandfasterreadout Smallpixelsincreasesnumberofsensorsrequiredtofillfocalplane Smallpixelsincreasenumberofpixelsoverwhichchargeisspread,thuslimitinglow-Esensitivity Largerpixelscouldbeusedtoperformsub-pixelcentroiding(thiswouldrequiredeepdepletionandmulti-pixelevents)
2) DeepDepletion ThickdevicesimproveQEabove5keVbut
coulddegradeenergyresolutionbelow1keV3) HigherFrameRates
Mitigatespileupandmayimprovebackgroundrejection,butincreasescomplexityandpowerofreadoutelectronics
KeyimprovementsoverACISandEPIC
Ordersofmagnitudehigherframerates(>100full-frame/sec,>10000subframe/sec) Significantlyimprovedradiationhardness Fullyaddressable(i.e.highspeedwindowing) NearFano-limitedresolutionoverentirebandpass Lowerpower Largeformat(upto4Kx4K)abuttabledevices
All have been demonstrated individually
HDXI: Technical Challenges
Hybrids and CCDs have achieved the depletion depths required
to make further developments to achieve these depletion depths
Monolithic architectures have achieved low read noise, but hybrids still need to progress further to achieve < 4 e-
All devices have achieved small pixel sizes, but further development is needed to do this while retaining other advantages and while limiting impacts of increased charge diffusion due to the increase in the aspect ratio of pixel depth-to-width;
pixel size, operating voltage, and depletion depth will need optimization
While higher frame rates are already possible with APSs, relative to CCDs,
frame rates and to achieve the required read noise while simultaneously achieving fast frame rates (>100 frame/sec for >16 Mpix camera)
STDT science discussions suggest Emphasis on soft (<1 keV
Primary technology development required for HDXI is sensor technology. Three technologies currently being developed – each meets some of the requirements but none presently meet all.
Some additional HDXI Technology Development
Additionaltechnicalandengineeringdevelopmentrequiredinthreeareas: DriverASICs
Dependingonsensortechnologychosenforflight,acustomASICmayneedtobedevelopedtoclocksensors.However,digitizationonchipcouldalleviatemuchofthis.
FPGA/EventRecognitionprocessors EventrecognitionwillbedoneinradiationtolerantFPGAswithsufficientprocessingpowertokeepupwithlarge(>2Gpix/s)dataratefromsensors.Requiresdevelopmentofflightfirmwareandsoftware
Opticalblockingfilters Largearea,thinunsupportedopticalblockingfilters(Alonpolyimide)needtodemonstratesufficientmechanicalandthermalstability
LynxX-rayObservatory–NotionalMissionLifecycleSchedule
Summary
HDXIwillachieve<0.5arcsecimagingresolution(<1arcsecoverar>10’fieldofview)whileperformingmoderatespectroscopy
HDXIwillenabledeepandwidesurveys,withminimalsourceconfusion
HDXIwillhavesoftresponse(<1keV),enablingstudiesathighredshift
TheHDXInotionaldesignhasbenefitedandmaturedrapidlyduetothestrongeffortsoftheMSFC-ACOinstrumentdesignprocessandtheGSFCInstrumentDesignLab(IDL)process.
TheLynxHighDefinitionX-rayImagerwillprovide:uniqueandextraordinaryscience-drivencapabilities
Thank You!
ForthelatestLynxnewsandevents,andtosignuptotheNewsDistributionvisitusat:
https://wwwastro.msfc.nasa.gov/lynx/
Optics
Multilayer Insulation and Coatings
Ultraflex Solar Panels (2)(5.7 m Dia.)
12 m
Outer Door(not shown)
OpticalBench
Spacecraft Bus (4.5 m Dia.)
InstrumentRadiators
InstrumentTable Enclosure
Backup Slides
CMOS Hybrid Sensors (PSU/Teledyne)
Hybrid CMOS X-ray detectors, Falcone et al.
Silicon detector array and readout array bump-bonded together – Allows separate optimization of detector and readout – Readout electronics for each pixel – Optical blocking filter deposited on detector
Based on IR detector technology with heritage from JWST and high TRL/flight-heritage from OCO
Back illuminated with 100-300 micron fully depleted depth àà excellent QE across 0.2-15 keV band Inherently radiation hard, with no charge transfer across detector Up to 4k×4k pixels, with abuttable designs High speed (10 Mpix/sec × N outputs) with low-power Read noise (~5-10 e-) needs improvement. Fano-limited performance is expected, with work in
progress.
Selection of recent progress Inter-pixel crosstalk eliminated with CTIA amplifiers Event-driven readout on 40 µm pixels (very fast frame rates) New test devices with small (12.5 µm) pixels and in-pixel CDS, fabricated and tested to have
~5.6 e- readnoise
Futurework: (1)scalingsmall-pixeltestdesignuptolargerdetector,(2)reducereadnoisefurtherwithimproved
componenttolerance,whilemaintaininglowreadnoiseathighreadoutrates,(3)attemptingtoimplementevent-drivenreadoutinsmallerpixels,(4)investigatingsub-pixelcentroidinginlargepixels
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Sarnoff
Digital CCD (MIT Lincoln Laboratory)
BuriedSenseGate
Gate
Source
Drain
High-SpeedDifferentialDigitaloutputs
Concept:HybridCCD-CMOSImager HighFrameRate
Veryfastoutputs(~5MHz) Integratedparallelsignalchains
LowNoise:High-responsivity,sub-electronreadnoiseamplifier
Low-power:CMOS-compatibleCCD
Currentstatus:CMOS-compatibleCCDwithconventionalamplifier: Noise<[email protected](25xfasterthanChandra)
ExcellentchargetransferatCMOSlevels(±1V;~sameclockpower/areaasChandra@25xhigherrate)
8μmpixels(oversamplesLynxPSF)
coun
ts/eV
TestDevice
Monolithic CMOS Sensors (SAO/Sarnoff )
BIMonolithicdevicewithOpticalBlockingFilterinSAOtestchamber
Noise<3e
Carbon(277eV).WithOBF.Nosourcefilter
Boron(185eV).PIXECm244source
1kby1k,16µmpitchdevices. Highsensitivity~135µV/epixel(<Carbonx-ray>produces~10mV@pixel!) Row-at-a-timeonchipCDS(1kby1kdevicecanCDSprocess1kpixelsin~20µ sec) [email protected] Highthrough-putmitigatesdarkcurrentandout-of-bandopticallight
PixelsizeandsoftresponsewellmatchedtoenvisionedLynxopticPSF2016APRA:DemonstratePMOSdevices(photoholesvsphotoelectrons)
Lowerreadnoise(~1hrms) “No”RandomTelegraphSignal(RTS)noise Lowerrecombinationofphotocharge