AMO Adventures at the LCLS

TheArgonneAtomic,Molecular,andOp6calPhysicsGroup’sexperimentsu6lizingtheLinacCoherentLightSource(LCLS)−thefirstX‐rayFree‐ElectronLaser

BertoldKrässigChemicalSciencesandEngineeringDivision(soon:X‐RayScienceDivision)ArgonneNaAonalLaboratory

APS/UsersMonthlyOperaAonsMeeAng,December16th,2009

Thanks to 33 Undulators from the APS

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X-Ray Flux: Per Pulse versus Per Second

LCLS:2×1012photonsperpulseat9keV;

2×1013photonsperpulseat750eV;

≈70‐300femtosecondspulselength

(≈1‐3femtoseconds,ifthebunchchargeisloweredfrom250pCto20pC)currently30HzrepeAAonrate,120Hzmaximum:

≤2.4×1015photonspersecond

Forcomparison,APS14‐ID(2undulators):

1010photonsperpulseat12keV;≈100picosecondspulselength;

6.5MHz,mechanicallylimitedto≤1kHz:

≤6.5×1016photonspersecond

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High Intensity X-rays

  2×1013photons  750eVphotonenergy  200fspulselength  1μm2focaldiameter 1.2×1018W/cm2

  Pulsesarespiky−>peakintensiAesarehigherthantheaverage  IndividualatomsabsorbmulAplephotonsduringasinglepulse

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“Unlocking the World of the Ultra Small and the Ultra Fast”

AMOquesPons

  fundamentalnatureofx‐raydamageathighintensity–  electronicdamage

–  CoulombexplosionAmescale

–  behaviorat>1018W/cm2–15Å

  nonlinearx‐rayprocesses

  roleofcoherence

  quantumcontrolofinner‐shellprocesses

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Before During ~10 fs After ~50 fs

Neutze,Wouts,vanderSpoel,Weckert,HajduNature406,752(2000)

3x1012 x-rays 100 nm spot 12 keV

10 fs ⇒ 1022 W/cm2

TheLCLSPosterChild

The First Endstation: AMO Physics

KBmirrors

HighFieldPhysicsChamber

Diagnos6csChamber

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The Components of the High Field Chamber

ionTOF

5eTOFsforangulardistribu6ons

Negasjet

JohnBozekChristophBostedt

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The First User Experiment , October 1−5, 2009 Tracking transient atomic states produced by ultraintense x-ray pulses

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TheTeamYuelinLi,ElliotKanter,BertoldKrässig,AnneMarieMarch,StevePram,

RobinSantra,SteveSouthworth,LindaYoungArgonne

JohnBozek,ChristophBostedt,MarkMesserschmidtLCLS

LouDiMauro,GillesDoumy,ChrisRoedigOhioStateUniversity

NoraBerrah,LiFang,MamhiasHönerWesternMichiganUniversity

PhilBucksbaum,JamesCryan,MikeGlownia,DavidReisPulseCenter,Stanford

Collaborators

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200 600 1000 1400 1800

photon energy (eV)

0.01

0.1

1

cro

ss s

ectio

n (

Mb

)

Ne photoabsorption

Neon, the Prototypical Atom

10electrons,groundstateconfiguraAon1s22s22p6

Bindingenergiesinneutralneon:

2p:21.6eV2s:48.5eV

1s:870.2eV

Thehigherthechargestate,thehigherthebindingenergies.

Atthreshold,thephotoabsorpAoncrosssecAonforthe1sshellis15Ameslargerthanforthevalenceshell.

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K-Shell Ionization (870 eV and above) Auger Decay

  K‐holestatelifeAmeτ=2.4fs

  PredominantlyAugerdecay(98.2%)

  K‐shellholeisfilledbyavalenceelectronandasecondvalenceelectronisemimed(Augerelectron)

  Augerelectronenergyisthebindingenergydifferencebetweentheinnerandvalenceshells

  DoubleK‐holes(hollowatom)giverisetohypersatellitetransiAons

  Double‐K/Single‐K=0.32(4)%(for5keVx‐rays,single‐photonabsorpAon,12‐ID)

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Southworth et al., Phys. Rev A 67 (2003)

Theory: Nina Rohringer and Robin Santra Phys. Rev. A 76, 033416 (2007)

  P:K‐shellphotoionizaAon

  A:Augerelectronemission

  V:ValenceionizaAon  SequenAalionizaAonPAVVVV…

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1013x‐rays230fs1µmspot

The “First Glimpse at the Experimental Data” will be posted after publication of this work

Thankyouforyourunderstanding.

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The Fifth Experiment at LCLS, Oct 30− Nov 3, 2009 Resonant nonlinear x-ray processes at high x-ray intensity

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TheSameTeamYuelinLi,ElliotKanter,BertoldKrässig,AnneMarieMarch,StevePram,

RobinSantra,SteveSouthworth,LindaYoungArgonne

JohnBozek,ChristophBostedtLCLS

LouDiMauro,GillesDoumy,ChrisRoedigOhioStateUniversity

NoraBerrah,LiFang,MamhiasHönerWesternMichiganUniversity

PhilBucksbaum,JamesCryan,MikeGlownia,DavidReisPulseCenter,Stanford

Schematic of the Two-photon 1s-2p Resonance Excitation

a)  ValenceionizaAonbyfirstabsorbedx‐rayphoton(orIRlaser)b)  1s‐2pexcitaAonat848.6eVbysecondabsorbedphoton;

resonantabsorpAon/sAmulatedemissioncyclingathighintensity(RabiFlopping)

c)  Augerdecay

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Theory: Nina Rohringer and Robin Santra, Phys. Rev. A 77, 053404 (2008)

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Single shot

average

Summary and Outlook

  TheLCLSisupandrunning.  TheArgonneAMOgrouphadtwosuccessfulexperimentsat

theLCLSinOctober2009.

  Thedatashowthesignaturesof–  sequenAalmulAphotonabsorpAon,–  doubleK‐hole(hollowneon)producAon,–  intensity‐inducedtransparency/saturableabsorpAon,–  1s‐2presonantabsorpAon.

  Dataanalysisisongoing.  Ournextrun:August1‐5,2010.Femtosecondx‐raytwo‐photonphotoelectronspectroscopyof

organicmolecules

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Heroes at the Main Control Center

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