Femtosecond pulse length and arrival time measurement of hard X-Ray FELs

143 Pages·2016·4.19 MB·English

by  Gorgisyan, Ishkhan

Femtosecond pulse length and arrival time measurement
of hard X-Ray FELs
THÈSE NO 7370 (2016)
PRÉSENTÉE LE 16 DÉCEMBRE 2016
À LA FACULTÉ DES SCIENCES DE BASE
LABORATOIRE DE PHYSIQUE DES ACCÉLÉRATEURS DE PARTICULES
PROGRAMME DOCTORAL EN PHYSIQUE
ÉCOLE POLYTECHNIQUE FÉDÉRALE DE LAUSANNE
POUR L'OBTENTION DU GRADE DE DOCTEUR ÈS SCIENCES
PAR
Ishkhan GORGISYAN
acceptée sur proposition du jury:
Prof. F. Mila, président du jury
Prof. L. Rivkin, Dr R. Ischebeck, directeurs de thèse
Prof. J. Hastings, rapporteur
Prof. T. Feurer, rapporteur
Prof. F. Carbone, rapporteur
Suisse
2016

Thinkofyourlifeasagreatestmiracle
anditwillbecomeone.
—Tvigern
ToSamvelGorgisyanandGoharIsrayelyan...

Acknowledgements
Iwouldliketoexpressmydeepestgratitudetomythreesupervisors,whohaveguidedme
throughoutmythesisandtaughtmesomuch,andwithoutwhomitwouldbeimpossible
toaccomplishthisproject;LeonidRivkinforconstructivecriticism,hisvaluableadviceand
support, Rasmus Ischebeck for his supervision, his endless positivity and for motivating
andhelpingmetodevelopasaresearcher,andPavleJuranicforsharinghisexperienceand
knowledgewithme,forallthefruitfuldiscussions,forhisassistanceandguidancetokeep
meontherighttrackintheproject.IfurtherthankLucPatthey,RafaelAbelaandChristoph
Hauriforsupportingthemeasurementsperformedduringmythesis.SpecialgratitudetoSven
ReicheandEduardPratforhelpingmetointerpretsomemeasurementresultsandexplaining
differentphenomenaoftheFELprocess. IthankthecolleaguesfromSACLAforproviding
agreatsupportduringthemeasurements,particularlytoMakinaYabashi,ShigekiOwada,
TetsuoKatayamaandTadashiTogashi.SpecialthankstothetechnicalstaffatPSIandSACLA
forhelpingduringthepreparationsforthemeasurements,especiallytoBeatRippstein,who
alsopracticedGermanwithme.IthankmycolleaguesfromtheAdvancedInstrumentation
group, who always gave useful feedback to my work. In addition to my group, I am also
thankfultotheBeamDynamicsgroupforthenicediscussionsoverlunchandcoffeebreaks,
forping-pongmatchesandtable-soccerbattles.Iwouldliketothankallmycolleaguesand
collaborators,whohelpedmeduringmyPhDandcontributedtomygrowthasascientist.
Iwanttothankallmyfriendsformakingmylifesobright,colorfulandfullofadventures
duringtheseexcitingyearsofmyPhD.Icanneverthankmyfamilyenough,whowasalways
thereforme,supportedmeineverythingandmademethepersonIamnow,withspecial
thankstomywifeJennyGorgisyanformotivatingandinspiringme.
IamalsogratefultoFrédéricChopin,JohannSebastianBach,GiuseppeVerdiandAntonio
Vivaldifortheirpricelessworksthatinspiredmeandkeptmefocusedduringmywork,aswell
astoPaco,SwiftGuad,D12andStromaeforgivingmeextramotivationwhenIneededitthe
most.
PSI,21September2016 I.Gorgisyan.
i

Preface
FreeelectronlasershavebecomethebrightestX-rayssourcesintheworld,enablingscientists
toperformresearchonthedynamicsofmolecularsystemsbyprovidingfemtosecondX-ray
pulses. The metrology for the arrival time and pulse length plays a central role for time-
resolvedexperiments.Thisworkpresentsthefirstmeasurementofpulselengthandarrival
timeofhardX-rays,withphotonenergiesupto10000eV.Itisbasedonterahertzstreaking
ofphotoionizedelectronsgeneratedbytheX-raypulseinadilutegastarget. Assuch,this
diagnostics is transparent and can be operated along user experiments. The instrument
developedintheframeworkofthisthesiswillbeusedforthetemporalcharacterizationofthe
X-raypulsesinSwissFEL,andwillprovideuserswithvaluablediagnosticsofpulsearrivaltime
andpulselength.
The present manuscript details the construction of the chamber, first tests using a high
harmoniclaser-basedsource,andmeasurementsatthefreeelectronlaserSACLAatSPring-8
inJapan. Thisalsoincludestheindividualmeasurementofthetwopulsesinthetwo-color
mode,arecentupgradeofthefacilitythatprovidestwooverlappingX-raypulseswithdifferent
wavelengthandvariabledelaythatcanbeusedforpump-probeexperiments.
PSI,02September2016
iii

Abstract
Theultra-brightshort-pulsedradiationprovidedbythefreeelectronlasers(FEL)isusedfor
manynewdiscoveriesindifferentfieldsofscienceandindustry.TheadvancementoftheFEL
technologiesallowsthegenerationofshorterphotonpulseswithhigherphotonenergiesor
shorterradiationwavelengthsthatopennewhorizonsforthenewresearch.Inordertobetter
understandthemeasurementsusingthefreeelectronlaserpulses,itisimportanttoknow
thepropertiesofthesepulses.Particularly,forthetime-resolvedexperimentsthetemporal
propertiesofthephotonpulsessuchastheirrelativearrivaltimesandthetemporaldurations,
areofutmostimportance.
OneofthetechniquestomeasuretheseparametersoftheFELpulsesistheTHzstreaking
method.Thusfar,thismethodhasbeenusedonlyforthephotonpulsesinultravioletandsoft
X-rayregions. Thisthesisprovidesafullcharacterizationofthemethodanddemonstrates
itsapplicabilityinthehardX-rayphotonenergyrange,measuringFELpulseswithphoton
energiesofupto10000electronvolts.Measurementaccuraciesofsub-10femtosecondswere
achievedforboththearrivaltimeandthepulselengthmeasurements. Furthermore, itis
shownherethattheTHzstreakingmethodisabletosimultaneouslymeasuretwoFELpulses
of different energies. The results from some measurements were also compared to other
independentmeasurementtechniques.
In addition to the performed measurements, simulation of the THz streaking effect was
performedtobetterunderstandthemeasurementmethod.Thesimulationsshowedtheways
ofachievinghigheraccuracieswiththeTHzstreakingtechniques.Theresultsobtainedfrom
theexperimentswereconsistentwiththeresultsprovidedbythesimulations.
TheresultsobtainedinthisthesisprovidenewpossibilitiesfortheapplicationsoftheTHz
streakingmethod.Theyenabletemporaldiagnosticsforphotonpulseswithawiderangeof
wavelengthsandtemporaldurations.Suchdiagnosticscancontributelargelytothesuccessof
theexperimentsperformedatfreeelectronlasersources.
Keywords: Freeelectronlaser,Temporaldiagnostics,Femtosecondmetrology,THzstreak
camera,Electrontime-of-flightspectrometers,Highharmonicgeneration,HardX-ray
v