SimulationsanddesignforsoftX-raybeamlinesatMAXIV

RamiSankari

SoftwareforOpticalSimulations,WorkshopTrieste,3-7October2016

Outline● MAXIVLaboratory● Descriptionofthebeamlines● Needsinsimulations

– Performance– Power,coolingandstability– Thesource– Coherence

● Resultsandconclusions

March2014

Overwiew

March2014

Injection

XRM2016,Yngve Cerenius

TwoinjectionsystemThermionicRFGun1nC @10Hz

PhotocathodeRFGun100pC @100Hz

Status:Inoperation≠Fullycommissioned

Photocathode RF Gun

Thermionic RF Gun

March2014

Linac

XRM2016,Yngve Cerenius

Thelinac• Length:300m(39sections)• 3.5GeV• 2transferpoints

Status:Inoperation

March2014

The1.5GeVring

XRM2016,Yngve Cerenius

The1.5GeVring• Circumference:96m• Ringlattice:doublebendachromat(DBA)• Storedcurrent:500mA• Straightsections:12(3.5m)• Emittance(hor):6nmrad

Status:Commissioning

March2014

The3.0GeVring

XRM2016,Yngve Cerenius

The3.0GeVring• Circumference:528m• Ringlattice:7bendachromat(MBA)• Storedcurrent:500mA• Straightsections:20(5m)• Emittance(hor):0.2-0.3nmrad

Status:Inoperation

March2014

TheSPF

XRM2016,Yngve Cerenius

TheShortPulseFacility• Pulses>≈100fs• Repetitionrate:100Hz

FemtoMAX beamline• Energyrange:1.8– 20keV• Photons/pulse:107

Status:Commissioning

March2014

Beamlines

XRM2016,Yngve Cerenius

BeamlinesBl fundedonthe3GeVring:8(19)Bl fundedonthe1.5GeVring:5(11)Bl fundedontheSPF:1(3)

Status:Variousdegreesofcompletion

XRM2016,Yngve cerenius

1. FemtoMAXfsdynamicsinsolid

2. NanoMAXNano-imaging&- spectroscopy

3. BioMAXProteinCrystallography

4. BalderChemicalspectroscopy:real-time&-condition

5. VeritasElectronic&magneticexcitations:solids

6. HippiePhotoemission:mBar gaspressure

7. ARPESElectronicstructure:solids

8. FinEstBeaMSElectronicstructure:gases,aerosols

9. SPECIESElectronic&magneticexcitations:surfaces

10. MAX-PEEMMicroscopy:surfaces

11. FlexPESElectronicstructure:surfaces&gases

12. CoSAXSGeometricstructure&correlation:(bio)liquids

13. SoftiMAXMicroscopy&methoddevelopment

14. DanMAXPowderdiffraction&imaging:materialsscience

20162017

20172018

Beamlines

DescriptionofthesoftX-raybeamlines

● VERITAS,3.0GeV ring– VeryhighresolutionRIXSspectroscopy– 275-1600eV– R=50000,500eV,1x1012 ph/s– Smallspot,always,

DescriptionofthesoftX-raybeamlines

● SoftiMAX,3.0GeVring– STXMandCXI– 275-2500eV– R≈5000– Spotca.20-30nmatSTXMbranchand

ca.20x20µm2 atCXIbranch

DescriptionofthesoftX-raybeamlines● ARPES,1.5GeVring

– VeryhighresolutionARPES– 10-200(1000)eV– R<1meV upto100eV– Mediumsizespot

DescriptionofthesoftX-raybeamlines

● SPECIES,1.5GeVring– RIXSandAP-XPS– 27-1500eV– R≈10000– SpotatRIXS<5x20µm2– SpotatAP-XPS60x100µm2

– PrototypeforMAXIVbeamlines– Complementary,lowenergybeamlinefor

HIPPIE

DescriptionofthesoftX-raybeamlines

● INSERTIONDEVICES– 3.0GeVring:ca.3.75mlongEPUs– 1.5GeVring:ca.2.5mlongEPUs

● Otherspecifications– 3.0GeV ring:ca.50mbeamlines– 1.5GeV ring:ca.30…40mbeamlines– Horizontalbeamatsample(!)– Experimentatreasonableheight(!)– Highflux,lowflux,highresolution,low

resolution,mediumspotwhichcanbereduced,orinsomecasesexpanded

DesignofthesoftX-raybeamlines

– Collectinginputfromtheusercommunities;convergencetofinalparameters

– Comparisonofvariousdesigns– aiminfindinglocaloptimum

– Extensivemodelingcorrespondingtofinaldesign• Reliableestimateofperformance• Tolerancesdefinedforopticalelements• Stability/vibrationsincludedforcheckingtheeffect

DesignofthesoftX-raybeamlines

- monochromator/gratings

- focusingtoslit

- refocusing

- source

DesignofthesoftX-raybeamlines

PracticallyallVUV- softX-raymonochromatorsatMAX-labwerebasedonplanegratings

– Experienceonworkingwiththem– Blazedplanegratingsavailableforreuse– Flexibleandyeteasytouse

PlanegratingmonochromatorilluminatedwithcollimatedlightchosenintheendforallpresentsoftX-raybeamlines.

DesignofthesoftX-raybeamlines

Havingalsothehorizontalfocusattheexitslitplaneincreasesachievableresolvingpower.

– Focusingwithfirstmirrorresultsinhighestresolvingpowerbutlowestdemagnification

– Focusinghorizontally(andvertically)withthefocusingmirrorincreasesdemagnification

– Havingacollimation-focusingpairbyfirstmirrorandfocusingmirrorgivesabitofbothadvantages

– Stigmaticfocusatexitslitallowsusingellipsoidalrefocusingmirrors

DesignofthesoftX-raybeamlines

Singlerefocusingmirror,ellipsoidalortoroidalusedforallexceptcoherentscatteringbeamline

– Singlereflection,lesslosses– Easytokeepbeamhorizontalatexperiment– Sagittalfocusinginverticaldirection– Aberrations(low)

– Rotationaroundthenormalofatoroidalmirror(yaw)allowstoenlargethebeam

– Beampositioncanbechangedalonghorizon(pitch)andperpendiculartoit(roll)

DesignofthesoftX-raybeamlines

Astigmaticfocusforrefocusingtoroidalmirrorallowstochangeitssourcesize(exitslitopening)withoutaffectingtheimagesizewhichisnowdictatedbythebeamdivergence.

DesignofthesoftX-raybeamlines

- power

- stability

- coherence

Mainfocusareas

- source

PowerfromasoftX-rayundulatorEllipticallypolarizingundulatorat3.0GeVring:

● EPU48– 48mmperiodlength,81periods,L=3905.5mm– Kmax =4.506,limitedtoK=3.30(6.2kW)– 275– 1500(1st harmonic)

Ellipticallypolarizingundulatorat1.5GeVring:

● EPU95p2– 95.2mmperiodlength,25periods,L=2380mm– Kmax =10.065(2.6kW)– 4– 1000– Experimentsupto1486.295eV(AlKa)

PowerfromasoftX-rayundulatorEPU48 EPU95.2

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Max.powerdensityat10m:26.6W/mm2 Max.powerdensityat10m:0.9W/mm2

Calculations with SPECTRAv10.

PowerfromasoftX-rayundulatorHeatloadinducedstructuralchanges,M1

Calculations with COMSOL,v3.5,www.comsol.com

PowerfromasoftX-rayundulatorHeatloadinducedstructuralchanges,apertureeffect

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0.150.100.050.00-0.05-0.10-0.15M1 length (m)

6σ illumination 9σ illumination

PowerfromasoftX-rayundulatorHeatbumpprofilescanbeinsertedintoraytracing

– SHADOW1,RAY2,RAY-UI3,XRT4,…– Mostheatbumpscanberegardedasadditionalconvexmirrors,radiusdefinesimagingeffect

– Densemeshorinterpolatingimportant– Loopingautomatizedfiniteelementanalysisintoraytracingpossible,andwithpresentcomputersthatisalsofeasible

1M.SanchezdelRio,N.Canestrari,F.JiangandF.Cerrina,J.Synchrotron Rad.18,708(2011);http://www.esrf.eu/Instrumentation/software/data-analysis/OurSoftware/raytracing2F.Schäfers in:ModernDevelopmentsinX- RayandNeutronOptics,(2008).3https://www.helmholtz-berlin.de/forschung/oe/fg/nanometeroptik/science/layout/ray_en.html4K.Klementiev andR.Chernikov,Proc.SPIE9209,92090A(2014);http://pythonhosted.org/xrt/

POSTERS:RAY-UI/PeterBaumgärtel/HZBMASH/PeterSondhaus/MAXIV

StabilityThecoolingsolutionpresentedearlierreliesonturbulent

flowinthenarrowcoolingchannelsundersurfaceofthemirror.

Totalwaterflowwillbeseverallitersperminute→largediameterfeedinglineneeded,withpracticalsizestheflowwillnotbelaminarthereeither.

Turbulenceinducedvibrationsbythecoolingchannelsandlinesisoneofthefutureforthestabilitygroup.

Stability

“Forestimatingvibrations,thetransitionpointsfromlaminartoturbulentflowneedstobeknown– measurementsneededtofixthosepoints.”

?

R&DPresentation,BrianNorsk Jensen,MAXIVLaboratory,calculationsbyKarlÅhnberg

Stability

Stability

R&DPresentation,BrianNorsk Jensen,MAXIVLaboratory,calculationsbyKarlÅhnberg

Gaussianapproximationiswidelyusedindescribingtheundulatorlightsource.However,precisecalculations*predictcleardeviationfromit,resultingin

i.e sourcesizeisabouttwiceaslargeastheonegivenbyGaussianapproximation.Withlowemittancestorageringsthisstartstodominatethesourcesizeanddivergence.

Anotherquestioncomeswithusingtheundulatoraswigglerforhighphotonenergies.

*P.Elleaume in:Undulators,wigglersandtheirapplications,eds.H.Onuki andP.Elleaume,Taylor&Francis,69-108(2003).

Thesource

ThesourceEPU48onaxis EPU481/Ndetuning

EPU95.2closedgap,1000eV

These calculations withSPECTRAv10,SRWalsoused forthese.

ThesourceForraytracingthesourcecharacteristicsweremodeledin

SPECTRA1 andSRW2 – thosevalueswereusedasinputparametersine.g.RAY.

Atpresent,theraytracing/wavepropagationprogramXRTisused.Itincludesalsonearfieldcalculationsforundulators,andcanuseelectrontrajectoriescalculatedwithRADIA3

1T.TanakaandH.Kitamura,J.SynchrotronRad.8,1221(2001).2O.Chubar andP.Elleaume,Proc.EPAC-98,1177(1998).3O.Chubar,P.Elleaume,andJ.Chavanne,J.SynchrotronRad.,5,481(1998).

PartialcoherenceLowemittancesynchrotronsprovidelightwithhighdegree

oftransversecoherence,sometensofpercentatfewhundredeV

Forapplicationsutilizingcoherence,likecoherentX-rayimaging,preservingandrefiningcoherencefortheexperimentiscrucial– thisappliesalsotodiffractionlimitedimagingwithzoneplates

PartialcoherenceChosetobemadebetweentwophilosophies:using

secondarysource,orundisturbedexpansionuntilfinal,acceptancelimited,refocusingmirror?

Lookingatpropertiesatfocus (andaround)– Size,divergence,flux– Coherencelength– Degreeofcoherence– flexibility

●where to put FZP?●what is the result if finite beam emittance?●what are the coherence properties?●how to isolate the coherent part?

image by K. Schulte

Partialcoherence

Partialcoherence

Partialcoherence

Partialcoherence

Partialcoherence

Partialcoherence

PartialcoherencePerformanceestimationfortheSTXMbranch;raytracinguntilgrating,wavefront propagationuntilsample

Partialcoherence

Finalsimulations,softX-raybeamlines

– Includerealopticsintosimulationswhendelivered– Possibleeffectofshapeoutsidetolerances– Slopeerrormapsinsteadofstatisticalslopeerrordistributions(collaborationwithHZB)

– Analysisoffinalperformance• Real-timemodellingassistedtuningwithinreach

Resultsandconclusions● Classicalraytracingstillthemaintoolforgeneraldesignwork

● Precisemodelingofthesourcemoreimportantforlowemittancerings

● Stabilityisvitalpartoftransportingthebeam– vibrationsneedtobeincludedintosimulation

● Partialcoherencerequireswavefront-basedapproach

● Toolsneedtobeeasytousebutmosttoolsexist

Acknowledgementstocolleaguesat