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 ≤70eV@0.277keV,≤150eV@5.9keV(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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Chandra/AC

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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Chandra/ACIS

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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<7e-RMS@2.5MHz(25xfasterthanChandra)

  ExcellentchargetransferatCMOSlevels(±1V;~sameclockpower/areaasChandra@25xhigherrate)

  8μmpixels(oversamplesLynxPSF)

Responseat@2.5MHzFWHM142eVat5.9keV

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)  Modestcoolingrequirements.BackthinnedbyMikeLesser@U.ofArizona  Highthrough-putmitigatesdarkcurrentandout-of-bandopticallight

PixelsizeandsoftresponsewellmatchedtoenvisionedLynxopticPSF2016APRA:DemonstratePMOSdevices(photoholesvsphotoelectrons)

 Lowerreadnoise(~1hrms) “No”RandomTelegraphSignal(RTS)noise Lowerrecombinationofphotocharge