SLAC UED/UEM Initiative and UED@ASTAX.J. Wang- May 20, 2014Accelerator Directorate Review on UED@ASTA1Fundamental Probes in the BESParameterElectronNeutronPhotonChargeMagnetic MomentMassSpinPolarizationForceElectrostaticNuclearElectromagneticSamplesThinThickMedium

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Users desire to use different probes to obtain complementary info on samplesElectrons & x-rays see electrons and proton, while neutrons can see nuclei

SLAC UED/UEM ini

Is also well aligned with the DOE mission that is to develop state of art intrumentation

3DOE BES Future Electron Scattering and Diffraction Workshop4

A Multidimensional Visualization of Real MaterialsB Atomic Scale Molecular ProcessesC - Photonic Control of Emergence in Quantum MaterialsD - Evolving Interfaces, Nucleation, and Mass Transport

Ultrafast Electron Diffraction and Microscopy Facility

B.1 Source (MeV) and Electron Optics:B.2 - Pump Technology

Vision: The SLAC UED/UEM facility will be the world leading electron scattering instrumentation facility, complementary to the LCLS X-ray FEL. The UED/UEM facility will possess unique capabilities that enable Grand Challenge science in chemistry, material science, physics and biology. The availability of intense THz, X-ray and optical laser pumping in conjunction with UED/UEM probes will open new scientific opportunities. The UED-UEM initiative at SLAC/Stanford

THzelectronbeam

56

SLAC Lab Agenda (2014)THzX-RayWhat is make the UED/UEM uniquesTwo things.One is uniques capble. And other is the broad user community.67

*base design - upgrade - blue sky R&D18 months (2015) 2016~48 months (2019)

SLAC UED/UEM SummaryFor picosecond resolution imaging, relativistic energies may be the only way to obtain high spatial resolution.

Point Spread Function at 200 keV, 1 ns050 nm100 nm-50 nm-100 nmPoint Spread Function at 5 MeV, 10 ps050 nm100 nm-50 nm-100 nmUltrafast (< 10 ps) imaging only possible at higher voltagesM. R. Armstrong, B. W. Reed, B. R. Torralva, and N. D. Browning, Appl. Phys. Lett. 90, 114101 (2007).8

R.Valle et al, Ultramicroscopy 27, 67 (1989)Large Scattering SignalPump-probe Velocity Mismatch103MeV UED60keV UEDtVM > 1pstVM < 10fsVe= 0.446cVe= 0.989c

10

R.F. Egerton et al. Micron 35399 2004) Sample DamageKnock onPulse radiolysisCharging

RF GunRFLaserLensSynUV OpticsUltrafast Electron Diffraction (UED)

SampleDetectorAxiconOPA / THZLa0.5Sr1.5MnO4: Orbit & Charge Orders

MeV-UED

BNL TEM12

RF GunRFLaserLensSynUV OpticsUltrafast Electron Diffraction (UED)

SampleDetectorAxiconOPA / THZ

Condenser& Nano-UED13

RF GunRFLaserLensSynUV OpticsUltrafast Electron Imaging (UEM)

SampleDetectorAxiconOPA / THZ

Condenser

ObjectiveProjector14UED @ ASTA?There are three potential sites at SLAC could be considered for the first phase of UED. Those three sites are ASTA, NLCTA and LCLS II injector. ASTA the most favorable site for fast impact experiments, Existing RF gun and infrastructure.Laser system.Synergy with LCLS cathode R&D thermal emittance reduction.X-band for beam diagnosticsConcerns:Impact to existing program: LCLS cathode R&D, semi-conductor cathode, and X-band testing programSpace and environment (temperature and vibration) safety (laser and radiation), budget and resource (manpower).Others

The Accelerator Structure Test Area (ASTA)

UED@ ASTA ObjectivesFY14

FePt2nmheat sinkGoal: understand & control materials processes related to heat-assisted magnetic recordingFirst 100 Femto-second MeV UED at high rep rate Order of magnitude improvement (120 Hz vs 10 Hz)MeV UED Ultrafast Science

Understand and quantum control of chemical reactions. Structure of intermediate states

Early Physics: UED@ ASTA (FY14)

Early Physics: UED@ ASTA (FY14)

Challenges in UED @ ASTATime and resourceInfrastructure upgrade ASTA bunker space and laser room air conditioningTechnical challenges:Electron beam line ( diagnostic, sample chamber and detector)Laser RF synchronizationLow level RF Klystron modulatorLaser transport and pump-probe optics

RF GunChallenges in MeV-UED - Timing Jitter 23RF OscillatorLaserRF DriveSampleCathode

Timing jitter tjitter =

23

ALD Review on UED@ASTA AgendaStartEndTimeTitleSpeaker8:008:300:30Executive session8:308:400:10Welcome and charge to the committeeBob Hettel8:409:100:30SLAC UED/UEM Initiative and UED@ASTAXJ Wang9:109:300:20Science enabled by the UED/UEM and early science at ASTA Hermann Durr9:309:500:20UED@ASTA project plan and ES&HCarsten Hast9:5010:050:15UED@ASTA beam line and mechanical layoutEric Bong10:0510:200:15Coffee break10:2010:500:20Beam Dynamics studyJuhao Wu10:4011:000:20RF power stabilityMinh Nguyen11:0011:200:20LLRF and timing triggers Stephen Weathersby11:2011:400:20Laser-RF timing and synchronizationJoe Frisch11:4012:000:20UED laser transport and pump-probe opticsRyan Coffee12:0012:200:20UED commissioningRenkai Li12:2001:150:45Lunch and discussion01:0001:450:45ASTA tourBldg. 4401:4503:302:00Executive session, report preparation + additional questions 03:00Coffee03:3004:300:30Close-out25SummaryUED@ASTA will be the first step toward SLAC UED/UEM facility, it will be the first UED breaking 100 fs barrier and enable some exciting science. We have a realistic plan to realize the first experimental in FY 2014.

The SLAC UED/UEM facility will be the world leading electron scattering instrumentation facility, complementary to the LCLS X-ray FEL. The UED/UEM facility will possess unique capabilities that enable Grand Challenge science in chemistry, material science, physics and biology. The availability of intense THz, X-ray and optical laser pumping in conjunction with UED/UEM probes will open new scientific opportunities.

25Modetime resolutionspatialresolutionPulsesPumpScience driver

UEDkHz10 - 100 fsatomic

Single/ multipleoptical, THz, X-rayQuantum Materials,Warm dense matter,Chemical dynamics, Nanoscience

UED-streaking100 fsatomicSingle (10ps)optical, THz, X-rayWarm dense matter

nano-UED~100 fs10 nmMultipleoptical, THz, X-rayQuantum Materials,Nanoscience

UEM

10 ps10 nmSingleoptical, THz, X-rayNanoscience, Quantum materialsWarm Dense Matter

high-resUEM~100 ps0.3nm Singlenone, opticalBio-structure,glass dynamics