LCLS-II and the futureApril 10, 2019Mike DunneDirector, LCLSSLAC National Accelerator Laboratory

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DOE Office of Basic Energy Science is driving a wealth of ambitious new science programs

“Round Table” assessmentsidentifying new opportunities

FOA in Ultrafast Science, targeting LCLS-II

LCLS development is being targeted to respond to these scientific challenges

“Grand Challenges”from BESAC

Over the past 5 years, the community has identified a broad suite of specific scientific opportunities for LCLS

HPL, SLAC Users from 32 US states,and 23 other countries

3Thank you! to all who have served on our PRP, SAC, UEC, SPC, workshops, …

Much is owed to those who devote their time to LCLS, including: • SAC and subcommittees: Strategic direction

• SPC: Integration into SLAC/Stanford• UEC: User community requirements

• PRP: Experiment priorities

• Annual Users Meeting: Broad engagement

LCLS-II was devised to open up a new era of precision science, and enable entirely new modes of experiment

The leap from 120 pulses per second to 1 million pulses per second will be transformative

LCLS~10 msec

~mJ, ~fs

~µsecLCLS-II

EuXFEL(FLASH)

Programmabletime structure:

LCLS-II LCLS-II-HE

LCLS

LCLS-II is being designed and delivered by a national partnership, with international collaboration from DESY and many others

•  50% of cryomodules: 1.3 GHz •  Cryomodules: 3.9 GHz •  Cryomodule engineering/design •  Helium distribution, including valve boxes •  Processing for high Q (FNAL-invented gas doping) •  50% of cryomodules: 1.3 GHz •  Cryoplant selection/design/installation/commissioning •  Processing for high Q

•  Undulators •  e- gun & associated injector systems •  Accelerator physics support

•  Undulator Vacuum Chamber •  Also supports FNAL w/ SCRF cleaning facility •  Undulator R&D: vertical polarization

•  R&D planning, accelerator physics & prototype support •  processing for high-Q •  e- gun option

LCLS-II Partners

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John Galayda,Project Director

Jeff SimsProject Manager

Tom PetersonTechnical Director

LCLS-II performance represents a huge leap in capability

Doubles the hard x-ray energy reach of the high peak power beam (120 Hz)

Delivers unprecedented average power

for 0.25 to 5 keV

(soft andtender x-rays)

High Average Brightness

1019

1020

1021

1022

1023

1024

1025

1026

102 103 104

Existing Rings

LCLS-I

rings under const.

Aver

age

Brig

htne

ss

(ph/

s/m

m2 /m

rad2

/0.1

% B

W)

Photon Energy (eV)

Up

to 1

0,00

0

LCLS-II

High Peak Brightness

102 103 104

Peak

Brig

htne

ss

(ph/

s/m

m2 /m

rad2 /0

.1%

BW

)

Photon Energy (eV)1022

1023

1024

1025

1026

1027

1028

1029

1030

1031

1032

10331034

LCLS-I

Existing Rings

rings underconstruction

x B

illio

n

LCLS-II

Now HXU - Cu SXU – Cu HXU - SC SXU - SC

Photon Energy Range (keV) 0.25 -12.8 1 - 25 0.25 - 6 1 - 5 0.25 - 1.6

Repetition Rate (Hz) 120 120 120 929,000 929,000

Per Pulse Energy (mJ) ~ 4 ~ 4 ~ 8 ~ 0.2 ~ 1

Photons/Second ~ 1014 ~ 1014 ~ 1014 ~ 1016 ~ 1017

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LCLS-II will transform our understanding of dynamics in real-world materials and chemical science systems

§ Connect spontaneous fluctuations, dynamics and heterogeneities on multiple length- and time- scales to bulk material properties

§ Study interacting degrees of freedom (e.g. unconventional superconductors)

§ Reveal coupled electronic and nuclear motion in molecules

§ Capture the initiating events of charge transfer chemistry with sub-fs resolution

Charge dynamics on fundamental timescales

Emergent phenomena in quantum materials

chargespin

orbital

lattice

Ultrafast High repetition rate Extreme brightness

§ Measure element-specific, local chemical structure and bonding

§ Study efficient, robust, selective photo-catalysts

Molecular dynamics with exquisite resolution

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The LCLS-II cryogenic plants

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LCLS-II cryomodules are now being installed in the tunnel

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LCLS-II variable gap hybrid undulators from the teams at LBNL and ANL

Frame

Horizontally polarized undulator for soft x-ray branch

Vertically polarized undulator for hard x-ray branchUndulator Hall

Variable gap undulators used in LCLS-II to provide

greater wavelength tuning flexibility

The Near Experimental Hall will have a new instrument suite (nominally 5 end-stations in 3 hutches – now on 2 levels)

• 7 instruments fed by a single undulator at present• 8 instruments available for LCLS-II (new soft & tender instruments)

NEH 1.1: Atomic, Molecular and Optical NEH 2.2: Soft X-ray ResearchNEH 1.2: Tender X-ray InstrumentXPP: X-ray Pump ProbeXCS: X-ray Correlation SpectroscopyMFX: Macromolecular Femtosecond CrystallographyCXI: Coherent X-ray ImagingMEC: Matter in Extreme Conditions

2 Soft X-ray

5 Hard X-ray

2 “tender” x-ray

SXU

HXU

FarHall

XCS MFX CXI MECNearHall

N1.1 N1.2 XPP

N2.2

~ 50 m ~ 70 m

11

12

Equipment removal is complete from the Near Hall and FEE

Hutch 1.1Hutch 1.2

Removed EquipmentRemoved Equipment

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The design of the new instruments for LCLS-II is now mature

RIXS Endstation

Liquid Jet Endstation

NAMASTE

DREAM

SCRFlinac

SCRF/Culinac

TMO RIXS

TXI

Large team effort,building from the success of LCLS

Instruments to date

The leap to high repetition-rate drives step-changes across all aspects of our work, engaging the whole lab

High power optics & precision diagnostics

Injector and accelerator capabilities

High power lasers and synchronization

High rate detectors

Massive scale data analytics and real-time controls

Theory and modeling

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Looking beyond LCLS-II, the science impact of the MECinstrument (funded by DOE-FES) has been very impressive

Wide-ranging research in the “extreme materials” and “dense plasma” states

measurements on the Hugoniot36. Our present data set extendsfurther, showing the disappearance of Bragg scattering data above1.2 Mbar. At higher pressures, the shock coalescence data are onthe isentrope37,38 slightly above the isotherm6, validating our under-standing of dense aluminium utilizing pressure, temperatures anddensities solely based on measurements.

Our findings demonstrate that spectrally and wavenumber-resolved X-ray scattering is applicable for thorough testing of radi-ation–hydrodynamic calculations and equation-of-state models.Our methods present unique highly resolved data for dynamichigh-pressure material science studies that require accurate knowl-edge of material properties at high densities and are applicable forfuture studies aimed at observing the effects of ionization on theequation of state under high compression. Only the unique proper-ties of the seeded X-ray laser at LCLS provide the accuracy of dataneeded to distinguish between theories and simulations on amicroscopic level.

MethodsThe initial proposal for hard X-ray self-seeding at LCLS is described in ref. 19. Theforward Bragg scattered beam consists of a ‘prompt’ transmitted beam and a delayedmonochromatic wake generated from the wings of the Bragg diffraction profile.The diamond (400) reflection was chosen as the wake monochromator for suitablecrystal perfection, angular width and low absorption. The approach to self-seedingmatched the electron bunch duration of ∼10 fs (20 pC) to the width of the first wakemaxima. The operational phase, following commissioning of self-seeded operation,has shown that the normal operation of hard X-ray self-seeding performs better withthe nominal 150 pC charge and the corresponding 50 fs pulse duration. Stability isimproved by a factor of roughly two compared with the low-charge operation, with asimilar reduction in the per pulse energy fluctuations. In addition, the pulse energyof the seeded beam is significantly improved with the longer pulse (highercharge) mode. The seeded beam normally gives a two to four times improvement intime-averaged X-ray power compared with a post-monochromator of similarbandwidth with similar pulse durations and shot-to-shot intensity fluctuations.The narrow seeded line, 0.4–1.1 eV full-width at half-maximum, for a 50 fs pulse

duration typically contains an average pulse energy of 0.3 mJ, with occasional shotsup to 1 mJ. The peak brightness of 2.7 × 1034 photons s–1 mm–2 mrad–2 at 0.1% BWis calculated from the measured pulse duration and a mean pulse energy of 0.3 mJ.

The DFT-MD simulations for this study were performed using the codeVASP38–41. The exchange correlation functional was approximated with thegeneralized gradient approach42,43 and the electron–ion pseudo-potential was takenwithin the projector augmented plane wave formalism44,45. Three electrons peratom were treated as valence electrons using a plane-wave expansion, and the tencore electrons were treated with the projector augmented wavefunctions formalism.The core radius was rC = 1.7aB, with aB = 0.53 Å. The Mermin functionalaccounted for thermal excitations. The electronic cutoff for the plane-waverepresentation of the wavefunction was set to 550 eV as tested to provide the freeenergy and pressure with an accuracy of ∼0.7%.

The simulations were performed in a super cell with constant number ofparticles, volume and temperature, with periodic boundary conditions. Thetemperature of the nuclei was controlled using a Nose thermostat46,47. A total ofN = 256 ions were used for the fluid. Initial runs were performed at lowertemperatures, starting with the ions in a face-centred cubic (fcc) lattice at densitiesappropriate for the experiment. The resulting ionic configurations were then usedas starting configurations for runs at the temperatures of interest. Brillouin zonesampling was validated by running part of each DFT-MD run with a 2×2×2Monkhorst–Pack k-point grid instead of just the Γ-point48. Pressure differencesof ∼0.5% were found. We used a 0.2 fs time step and ran the simulations for2,000–23,000 steps. An initial relaxation time of varying length was excludedfrom analysis of the equation of state.

Received 21 October 2014; accepted 17 February 2015;published online 23 March 2015

References1. Ross, M. The ice layer in Uranus and Neptune—diamonds in the sky? Nature

292, 435–436 (1981).2. Benedetti, L. R. et al. Dissociation of CH4 at high pressures and temperatures:

diamond formation in giant planet interiors? Science 286, 100–102 (1999).3. Coppari, F. et al. Experimental evidence for a phase transition in magnesium

oxide at exoplanet pressures. Nature Geosci. 6, 926–929 (2013).4. Ernstorfer, R. et al. The formation of warm dense matter: experimental evidence

for electronic bond hardening in gold. Science 323, 1033–1037 (2009).5. Glenzer, S. H. et al. Symmetric inertial confinement fusion implosions at

ultra-high laser energies. Science 327, 1228–1231 (2010).6. Young, D. A., Wolford, J. K., Rogers, F. J. & Holian, K. S. Theory of the

aluminum shock equation of state to 104 Mbar. Phys. Lett. 108, 157–160 (1985).7. Ma, T. et al. X-ray scattering measurements of strong ion–ion correlations in

shock-compressed aluminum. Phys. Rev. Lett. 110, 065001 (2013).8. Ravasio, A. et al. Direct observation of strong ion coupling in laser-driven

shock-compressed targets. Phys. Rev. Lett. 99, 135006 (2007).9. Ciricosta, O. et al. Direct measurements of the ionization potential depression in

a dense plasma. Phys. Rev. Lett. 109, 065002 (2012).10. Nagler, B. et al. Turning solid aluminium transparent by intense soft X-ray

photoionization. Nature Phys. 5, 693–696 (2009).11. Focher, P., Chiarotti, G. L., Bernasconi, M., Tosatti, E. & Parrinello, M.

Structural phase transformations via first-principles simulation. Europhys. Lett.26, 345–351 (1994).

12. Driver, K. P. & Militzer, B. All-electron path integral Monte Carlo simulations ofwarm dense matter: application to water and carbon plasmas. Phys. Rev. Lett.108, 115502 (2012).

13. Garcia Saiz, E. et al. Probing warm dense lithium by inelastic X-ray scattering.Nature Phys. 4, 940–944 (2008).

14. Louis, A. A. & Ashcroft, N. W. Extending linear response: inferences fromelectron–ion structure factors. Phys. Rev. Lett. 81, 4456–4459 (1998).

15. Benuzzi-Mounaix, A. et al. Electronic structure investigation of highlycompressed aluminum with K edge absorption spectroscopy. Phys. Rev. Lett.107, 165006 (2011).

16. Lévy, A. et al. X-ray diagnosis of the pressure induced Mott nonmetal–metaltransition. Phys. Rev. Lett. 108, 055002 (2012).

17. Emma, P. et al. First lasing and operation of an ångström-wavelengthfree-electron laser. Nature Photon. 4, 641–647 (2010).

18. Milathianaki, D. et al. Femtosecond visualization of lattice dynamics inshock-compressed matter. Science 342, 220–223 (2013).

19. Amann, J. et al. Demonstration of self-seeding in a hard-X-ray free-electronlaser. Nature Photon. 6, 693–698 (2012).

20. Boehler, R. Temperatures in the Earth’s core from melting-point measurementsof iron at high static pressures. Nature 363, 534–536 (1993).

21. Purvis, M. A. et al. Relativistic plasma nanophotonics for ultrahigh energydensity physics. Nature Photon. 7, 796–800 (2013).

22. Kritcher, A. L. et al. Ultrafast X-ray Thomson scattering of shock-compressedmatter. Science 322, 69–71 (2008).

3 4 5 6 7 80

1

2

3

4

5

61.0 2.0 3.01.5 2.5

Mass density (g cm−3)

Tota

l pre

ssur

e (M

bar)

Compression (ρ/ρ0)

Single shock data (liquid S(k))

Double shock data (liquid S(k))

DFT-MD, (ref. 34)

Principal Hugoniot, (ref. 6)

DFT-MD, (this work)

Low T isotherm, (ref. 6)

Single shock data (solid-liquid)Shock data (compressed solid)

Te = 1.75 ± 0.5 eV

Te = 1.5± 0.7 eV

SESAME 3700* - isentropeSESAME 3719* - isentrope*(ref. 37)

Melt line

Figure 5 | Pressure–density diagram. A comparison of the pressure data forcompressed dense aluminium measured with varying laser intensities isshown for single shocks and during shock coalescence of two counter-propagating shock waves. The single shock data follow the shock Hugoniotand DFT-MD simulations from ρ= 3.5 g cm–3 to about ρ=4 g cm−3, wherethe shock waves coalesce and the pressure values approach an isentrope(above the ΔT=0 isotherm) to ρ= 7 g cm–3. The melt line (labelled dashedline) indicates the complete disappearance of shifted Bragg peaks in thewavenumber scattering measurements. The DFT-MD simulations of this workshow excellent agreement with the measured density and temperature data.

ARTICLES NATURE PHOTONICS DOI: 10.1038/NPHOTON.2015.41

NATURE PHOTONICS | VOL 9 | APRIL 2015 | www.nature.com/naturephotonics278

“Diamond rain” (replicating Neptune)

Shock formation in meteor impacts

Observing twinning deformation

Imaging shock waves in solid matter

Nanostructured dense plasma dynamics

Warm Dense Matter

Al

Dense plasma ion features

The success of MEC has underpinned a major new project to expand to the “petawatt” power level

CD-0 (“mission need”) approved by DOE in January. Funds provided to LCLS for CD-1 (“design selection")Specific building and laser options now being evaluated

One option: Build a new experimental hall to the east of the FEH

N

16

PW and kJ scaleperformance

AlanFry

CarolynGalayda

GillissDyer

LCLS-IILCLS-II-HE

LCLS

FACET-II

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LCLS-II-HE (“High Energy”) will extend the high average powerfrom 5 keV to a limit of at least 13keV, and possibly up to 20 keV

17

1000x

Early investment and foresight has provided SLAC with a flexible platform for future growth

GregHays

SusanaReyes

LCLS-II-HE will enable structural dynamics at the atomic scale

LCLS-II-HE provides the ability to study non-equilibrium phenomena and move beyond idealized materials and systems

Heterogeneity & complexityin ground & excited states

§ Correlate catalytic reactivity and structure

§ Real-time evolution with chemical specificity and atomic resolution

Dynamics of biomolecules & molecular machines

§ Study large scale conformational changes via solution scattering

§ Physiological conditions

§ Dynamics ties structure to function

§ Characterize statistically dynamic systems without long-range order

§ Inform directed design of energy conversion and storage materials

Ground State Fluctuations& spontaneous evolution

ion

ion3d metal-oxide

electrode

t1t2

t3

delay Dt

hn

hne-

CXICXI of heterogeneous nanoparticles in situ

Möller et al., Nature Comm. (2014)

activesite

~kT

Conformational (PE) landscape

… and beyond ??

+24.5°

8 GeVESA

XFEL-

O

CuRF, km-2 CuRF, km-3

17 GeV at 360 Hz25 GeV at 120 Hz

50-200 eVESB VUV, PMU-12.5°

HXR: 1-12 keV (1-50)µ

+4°

5-15 k

eV

HPHXR, SCU

25-100 keV

UHXR, SCU+2°

+0°-0°

-4°

-2°0.25-4 keV

HPSXR, PMU

SCRF, km-1

HXR: 1-12 keV (1-50)

HPSXR, 0.25-4 keV PMU

HPHXR, 5-15 keV SCU

Not to scale3.7 GeV

SCRF beam

SXR

Farm

multi-undulator

4-7 GeV at 1 MHz

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Key to the success of LCLS is being embedded in the wider capabilities of SLAC National Accelerator Laboratory, …

Cryo-EM

(You Are Here)SSRL

… with amazing teams from Facilities, Communications, ES&H, Business, IT, Legal, HR, CACM, and the Director’s Office

MeV-UED

Energy SciencesFundamental Physics

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… along with our integration into Stanford University, …

… coupled to extensive collaboration with our international partners, …

… the vision, support, and broad network of the DOE Office of Science, …

Largest Supporter of Physical Sciences in the

U.S.

Research ProgramsResearch to Universities

Over 22,000 Scientists Supported

Funding at >300 Institutions including all

17 DOE Labs

Facility Operations Major Projects

Nearly 32,000 Users of 26 SC Scientific Facilities

… the thousands of ‘unique users’, students and interns…

… and, of course, our wonderful staff …

… from across SLAC

… LCLS-II groundbreaking …

… LCLS staff, attentivelylistening to a lecture…

… Accelerator Directorate …

From initial vision

…. to early scientific impact,

… unprecedented measurements,

… accessing critical new regimes,

… and exploration of new frontiers.

It is clear that the X-ray laser revolution will continue to drive a new era of Grand Challenge discovery science