Date: Page:

X-ray sources for user-applications at ELI Beamlines

J. Nejdl,1,2 O. Hort,1 D. Mai,1 U. Chaulagain,1 M. Kozlová,1,2

V. E. Nefedova,1,3 K. Boháček,1,3 M. Albrecht,1,3 O. Finke,1,3 N. Nowak,1

S. Sebban, 1 J. Gautier, 1and G. Korn,1

1 ELI Beamlines project, Institute of Physics AS CR, Prague, Czech Republic

2 Institute of Plasma Physics AS CR, Prague, Czech Republic

3 FNSPE, Czech Technical University in Prague, Czech Republic

Outline

• Brief overview of the ELI Beamlines facility

• Laser driven XUV/X-ray sources

• HHG beamline

• Correlation of HHG properties with IR laser spectral

features

• Plasma X-ray source

• Betatron/inverse Compton beamline

• Laser Undulator X-ray Source/ Laser-driven FEL (A. Molodozhentsev, S24)

Facility layout and laser drivers for X-ray sources

Laser L1 L2 L3 L4

Energy (J) 0.1 > 20 30 1200

Pulse duration (fs) < 20 20 - 30 30 120

Wavelength (nm) 850 850 820 1060

Rep. rate 1 kHz >10 Hz 10 Hz 1/min

L1 laser system

Laser hall with ALLEGRA laser8 June 2018

Available for experiments:

September 2018 12 mJ / <15 fs / 1 kHzApril 2019 30 mJ / <15 fs / 1 kHzEnd 2019 110 mJ / <15 fs / 1 kHz

L3 laser system10 Hz, 1 PW (30 fs)

Experimental halls

E1:HHG+ PXS

E2: Betatron/Compton

E5: LUX/FEL

L4 compressor

E3: Plasma & HEDPE4:ion

acceleration

E5: electron acceleration

Laser-driven x-ray sources : several approaches

Betatron/ComptonPlasma X-ray source

6 mJ laser

(35 fs)

100 mJ laser

(20 fs)

photon energy 3 - 40 keV 3 – 80 keV

photons/(4π sr line or

1keV @10keV)> 1E7 > 1E9

Source size < 100 µm < 100 µm

pulse duration < 300 fs <300 fs

L1 driver1 kHz, 100 mJ, 20 fs

L3 driver10 Hz, 30 J, 30 fs

High-order harmonic beamline

6 mJ, 35 fs

from 2018

L1: 100 mJ, <20fs

from late 2019

Wavelength 10 -120 nm 5 -120 nm

Photons/shot 1E7 to 1E9 few 1E9 -1E12

Duration < 20 fs < 10 fs

Polarization Linear Lin./Circ./Eliptic.

Betatron Compton

photon energy 10- 100 keV 50 – 5000 keV

photons/shot > 1E8 > 1E8

Source size < 10 µm < 10 µm

pulse duration < 30 fs < 30 fs

Astrella backup1 kHz, 6 mJ, 35 fs

7+ Laser undulator X-ray source/ FEL (see A. Molodozhentsev’s talk, S24)

E1 E2/E3

E1 experimental hall

Experimental hall E1 (June 2018 status): applications of optical, VUV and X - ray light sources, area ready for use

HHG source of VUV photons

PXS + TREX: hard X-ray diffraction + spectroscopy

SRS station: optical spectroscopy

MAC station:AMO science + coherent imaging

ELIps:VUV ellipsometry

L1 laser beam transport

High-order harmonic (HHG) beamline in E1

GOAL: high flux ultra-short pulses of tunable coherent XUV radiation

• High energy kHz laser driver (L1: 100mJ in 20fs)

long focusing big generating volume high energy output (eff. 10-4-10-6)

and/or two color driver (50 mJ IR, ~20 mJ blue)

Focusing chamber f-number 40-1000

Interaction chamber

IR rejection+ diagnostics

Output of HHG beamline achieved & expected

• System verified with 1 kHz, 5 mJ, 40 fs laser

• L1 laser design parameters: 1 kHz, 100 mJ, < 20 fs

10

Laser system Gas λXUV, nm Driver F#

XUV pulse

energy, J

XUV divergence,

mrad

5 mJ, 40 fsXenon ≥51

280 0.05 0.6

100 mJ, 20 fs 1430 2 0.1

5 mJ, 40 fsArgon ≥32

120 0.005 0.8

100 mJ, 20 fs 625 0.2 0.15

5 mJ, 40 fsNeon ≥13.5

87 5×10-4 0.48

100 mJ, 20 fs 444 0.02 0.09

5 mJ, 40 fsHelium ≥10

75 5×10-4 0.4

100 mJ, 20 fs 380 0.02 0.07

L1 rump-up schedule:

30 mJ- December 2018 >50 mJ - June 2019 100 mJ – February 2020

HHG beam diagnostics

1. Wavefront sensor:

Hartmann type

Accuracy < l/5

2. Absolute off-line energy meter:

calibrated Si photodiode

3. Relative on-line energy meter:

photocurrent from filters

signal without amplification:

0 2 4 6 8 10 12

x 10-7

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Xe, f=5000 mm, 3.5 cm, 12 mbar

time (s)

U (

V) ][,

][ , )(1 2

1

JRes

QE

C dttUR

Q

XUV

t

t

=

=

20 40 60 80 100 1200

0.05

0.1

0.15

0.2

0.25

l (nm)

Responsiv

ity (

A/W

)

-6 -4 -2 0 2 4 6 8 10

x 10-7

-12

-10

-8

-6

-4

-2

0

x 10-4

time (s)

U (

V)

PV=1.9l

RMS=0.37l

HHG beam diagnostics

1. Spectrometer: toroidal mirror and spherical VLS grating

+ variable slit (for spectral resolution vs. sensitivity)

- Spectral range: 5-120 nm (two gratings: 600 l/mm and 1200 l/mm)

Spectra with 5 mJ, 40 fs, 1 kHz laser driver (Coherent Astrella):

Ne

∆𝜆

𝜆< 10−2

September 2018: first L1 – E1 run

• L1 laser frontend (1 mJ) compressed to 15 fs

• Test of the Beam Transport system

• HHG in Ar and Ne

• Broader harmonicshigher cutoff

13

Astrella: l=810 nm, t=40 fs, L1: l=830 nm, t=15 fs

Efficiency control of HHG using driving laser spectral features

Correlation of IR spectral shift

and XUV Conversion efficiency

lc=807 nm lc=804 nm lc=801 nm

HHG far-field HHG far-field HHG far-field

Efficiency control of HHG using driving laser spectral features

Ionization degree fullfilling phase-matching is critical for efficient generation

Effect on the fieldsMediumLaser

Proper intensity Proper ionization degreePhase-matching

IR spectral shift

V. E. Nefedova et al., Appl. Phys. Lett. 113, 191101 (2018)

HHG spectral variation

Correlation of IR and XUV

spectra simultaneously

V. E. Nefedova et al., Phys. Rev. A 98 033414 (2018)

Microscopic effects (Intensity dependent phase) X Macroscopic effects (laser blueshift during propagation)Short X Long trajectory

Plasma X-ray Source (PXS): femtosecond X-ray tube

17

Table 1: X-ray source

parameters

Phase I (M0) (M1)

5 mJ laser pulse

energy

Phase II (M2)

100 mJ laser pulse

energy

User operation

milestone (UOM)

Minimum hard x-ray

photon energy3 keV 3 keV 3 keV

Photons per shot

(photons/(4π sr line) or

photons/(4π sr 1keV)

@10keV)

> 107 > 109 > 109

Source size Less than 100 µm Less than 100 µm Less than 100 µm

Hard X-ray pulse duration

(FWHM)Less than 300 fs Less than 300 fs Less than 300 fs

Collimated No No Focusing optics

4π sr emission, 3 – 30 keVline + continuous spectra100s femtosecond pulses10s μm spot size

Characteristics

Time-resolved X-ray diffractionSmall- angle X-ray scatteringX-ray Absorption SpectroscopyX-ray ImagingPulsed radiolysis

Applications

E1

Plasma X-ray Source

Plasma X-ray source

polychromatichigh fluxsmall spot sizeOR point source

Diffractionmonochromaticlow divergence

ImagingRadiolysis

SpectroscopyPXS-BL2

PXS-BL1

10 eV 100 eV 1 keV 10 keV 100 keV

HHG

LUX

PXS

Betatron

X-ray diagnostics included:

– Single photon counting spectrometer (multi-shot)

– Shot-to shot X-ray pulse energy monitor

106 photons/shot on sample

19

ELI Beamlines experimental halls

E1:HHG+ PXS

E2: Betatron/Compton

E5: LUX/FEL

L4 compressor

E3: Plasma & HEDPE4:ion

acceleration

E5: electron acceleration

Betatron / inverse Compton in E2/E3

22

Characteristic Parameters of Betatron radiation

10/12/2018

Source size: 1-5 m

Critical Energy: 20 -50 keV

Number of Photons: 109 - 1010/shot

Pulse duration ~ 30 fs

Beam divergence < 20 mrad

L4 beam

L3 b

eamExperimental hall E3Plasma Physics platform (P3)

• Betatron/Compton source (driven by 1 PW)

for plasma and WDM diagnostics

• Focusing (f# = 20) with spherical mirror

• Operational from mid 2019

Experimental hall E2

• Independent beamline

for ultrafast X-ray science, imaging etc.

• Focusing by OAP (f# = 20)

• Designed for high rep. rate (10 Hz)

• Operational from end 2019

Betatron/Compton beamline in E2/E3

23

Radiation shielding in E2

4 hours operation at 10 Hz (e-beam 200 pC, 1 GeV) 0.1 to 1 µSv per day outside E2

Electron dynamics in molecules. Structure of non-reproducible biological particles.

X-ray Imaging. Movies of transient effects in large specimens

Initiate and study transient processes in molecular dynamics and material sciences

Sub-ps resolution of atomic scale structural dynamics (time resolved protein crystallography)

Properties in new surfaces and interfaces, charge and spin dynamics (electronic and magnetic properties)

SRS +pumps

PXS

HHG betatron1E10 ph10 fs1 kHz

1E13 ph300 fs1 kHz

1E8 ph20 fs10 Hz

LUX 1E6 ph5 fs5 Hz

10 keV

1 keV

100 eV

10 eV

1 eV

100 keV

1 MeV

Compton

5 mrad 4πsr

20 mrad

Secondary photon sources

Photon in/photon out experiments in the THz to Hard X-ray range-fs to ms dynamics

1 mrad

We are at your disposal as a user facility!

Fyzikální ústav AV ČR, v. v. i. Na Slovance 2

182 21 Praha 8 info@eli-beams.euwww.eli-beams.eu

THANK YOU FOR YOUR ATTENTION

Jaroslav.Nejdl@eli-beams.eu

Fyzikální ústav AV ČR, v. v. i. Na Slovance 2

182 21 Praha 8 info@eli-beams.euwww.eli-beams.eu

EXTRA SLIDES

Jaroslav.Nejdl@eli-beams.eu

niz

atio

npro

babili

ty

1.5 2

Intensity (1014

W/cm

Io

4 5

Intensity (1014 W/cm 2)

6 7 8 9

Intensity (1015

W/cm2)

0.01

0.02

0.03

0.04

0.05

niz

atio

np

robabili

ty

0.06

6 50

Io

0.01

0.02

0.03

0.04

0.05

0.06

niz

ation

pro

ba

bili

ty

0.07

30

Io

2.52)

0.1

0.2

0.3

0.4

10

Neon Helium

Argon

b

c d

0 0.02 0.04 0.060

Ionization probability

a

5

10

15

20

25

30Ar

He

Ne

L,

cm

coh

I II III

II IIII IIIIII

IR laser spectral shift vs HHG conversion efficiency

• Phase-matching on the rising edge

• Spatio-temporal distortions of the driving

field by plasma (1D model fails)

ηpeak ≥ ηPM

▪ Phase-matching at the peak of the pulse

▪ Keeping initial spatio-temporal pulse properties

during HHG

ηpeak = ηPM

ηpeak < ηPM

V. E. Nefedova et al., Appl. Phys. Lett. 113, 191101 (2018)

ηPM

Ionization degree fullfilling phase-matching is critical for efficient generation

• Phase-matching hasn’t reached (low ionization)

I II III

HHG spectral variation

Model: Dldip at time with ionization suitable for phase-matching

𝐀𝐫𝐠𝐨𝐧: 𝒂 ≈ 𝟎. 𝟗 𝐬𝐡𝐨𝐫𝐭 𝐭𝐫𝐚𝐣𝐞𝐜𝐭𝐨𝐫𝐲 𝐝𝐨𝐦𝐢𝐧𝐚𝐭𝐞𝐬

Dipole phase contribution

𝑞 × ∆λ𝑠ℎ𝑜𝑟𝑡

𝑞 × ∆λ𝑙𝑜𝑛𝑔

Measurement vs. model

∆λ𝑞= 𝑎 × ∆λ𝑠ℎ𝑜𝑟𝑡 + 1 − 𝑎 × ∆λ𝑙𝑜𝑛𝑔 + 𝑘∆λ𝐼𝑅𝑞

𝑘 …effect of long medium length

V. E. Nefedova et al., Phys. Rev. A 98 033414 (2018)