New opportunities with X-ray Laser Sources

Transcription

1 WIR SCHAFFEN WISSEN HEUTE FÜR MORGEN Luc Patthey :: SwissFEL Photonics :: Paul Scherrer Institut New opportunities with X-ray Laser Sources Symposium on OLAC 2018: NTB Campus, Buchs:

2 X-ray and light sources X-Ray Source Milestones 1895 Röntgen (Würzburg) 1953 Rotating-anode (Rigaku) 1947 Synchrotron radiation (GE) st generation synchrotron (NBS) - parasitic nd gen. (Daresbury) - dedicated to SR rd gen. (Grenoble) - undulators rd + gen. (SLS, Villigen) - high-brightness th gen. (Stanford) - X-ray Free Electron Laser Bending magnet

3 PSI s newest large-scale research facility: An x-ray free-electron laser (FEL) Synchrotron light, resolution: - spatial: fine - temporal: slow Optical laser, resolution: - spatial: coarse - temporal: fast X-ray free-electron laser excellent spatial (Å) and temporal (fs) resolution Direct insights into physical, chemical and biological processes governing our everyday lives

4 X-ray Free Electron Laser (X-FEL) Experimental station X-ray Pulse length 1-50 fsec Beamline 150 m laser pulse Undulator 50 m LINAC 0.6 km electron gun

5 History of the peak brilliance of x-ray sources Unique properties of x-ray FEL pulses: 1). Shortness 2). Brilliance 3). Coherence Peak brilliance: photons / (s mrad 2 mm 2 0.1% bw)

6 low gain exponential gain (high-gain linear regime) non-linear log (Power) P(z) = P o exp(z/l gain ) gain ~ 10 5 Saturationslength ~ 10 L gain Length Process: self-amplified spontaneous emission (SASE).

7 World map of x-ray free-electron lasers FLASH 2005 Eu-XFEL 2017 LCLS 2009 LCLS-II 2020 SwissFEL 2016 FERMI 2011 SACLA 2011 PAL-XFEL 2016 Hard x-rays Soft x-rays Operational Under construction

8 SwissFEL in a nutshell 1 st construction phase BC1 BC2 Injector Linac 1 Linac 2 2 nd construction phase ATHOS nm GeV Linac GeV 2.0 GeV 3.0 GeV GeV user stations ARAMIS nm Main parameters Wavelength: 1 Å 5 nm Photon energy: kev Pulse duration: 1 20 fs e - Energy 5.8 GeV e - Bunch charge pc Repetition rate 100 Hz ARAMIS Hard x-ray FEL, λ = 1 Å ( kev) Linear polarization, variable gap undulators Operation modes: SASE & self-seeded First users 2018 ATHOS Soft x-ray FEL, λ = nm ( ev) Variable polarization Apple X undulators Operation modes: SASE (CHIC) & self-seeded First users 2021

9 Jan. 13, 2013 SwissFEL Status

10 SwissFEL Status Building Injector & Linac Undulators ARAMIS Beamline

11 SwissFEL Status Building Injector & Linac Feb 16 May 16 first day&night users of game operation crossing established observed (by night shift) Undulators ARAMIS Beamline

12 SwissFEL Progress 2017 Kα from Fe 3 kev measured with Neon Gas intensity monitor FEL beam on YAG screen Kα 1 Kα 2 1eV Dec 16 Inauguration and 1 st lasing E e = 0.35 GeV = 240 Å Lasing E e = 0.91 GeV = 41 Å 15 May 17 Lasing at 41 Å May Lasing E e = 1.62 GeV = 13 Å 1 st Photons in X-ray beamline Aug Lasing E e = 2.45 GeV = 5 Å First user experiment in Bernina Oct Nov Achieved First user experiment in Alvra Dec CDR nominal e - energy 2.7 GeV 5.8 GeV e - pulse charge 200 pc 200 pc FEL wavelength 4 Å 1 Å FEL pulse energy 250 J 150 J Repetition rate 10 Hz 100 Hz

13 Scientific Challenges

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15 Pump-probe experiments at FELs

16 Non Linear Optics: Time resolved chemistry Canton, Kjær et al., Nat. Commun. 6, 6359 (2015) Canton, Kjær et al., Nat. Commun. 6, 6359 (2015)

17 Measure before destroy R. Neutze, Nature 2000

18 Visualizing dynamics in Biology at PSI Visualizing the motion of an object helps to understand its function Dynamic in vivo X-ray imaging in the mm range with high μsec resolution (Synchtrotron) dynamic processes in biochemistry in atomistic detail with up to picosecond resolution (Free Electron lasers) Extracellular Cytoplasmic Mokso et al., Scie. Rep., 2015 Standfuss et al., Nature, 2011 Nango et al., Science 2016 (SACLA) Nogly et al., Nature Comm 2016 (LCLS)

19 First time resolved Pilot Experiment by SwissFEL: Semiconductor to metal transition in Ti3O5 nanocrystals Collaboration: SwissFEL Bernina team and M. Cammarata et al., Univ. Rennes in collaboration with prof. S. Ohkoshi & H. Tokoro (Tokyo University) Nature Chemistry : /nchem.67 3 rd Harm: ~ KeV (220 1 st harm) Laser: 800nm, 42 mj/cm 2 Jungfrau 1.5 M (average 100 images) Light induced Debye Scherrer ring differences Precisely Mapping Multiscale dynamics from ~1 ps to tens of μs Acoustic expansion precedes phase transition(s) High resolution allowed understanding transformation pathway: β α λ

20 First Pilot Experiment by SwissFEL-Alvra: UV photo-induced charge transfer in OLED system Collaboration SwissFEL Alvra team and J. Szlachetko, J. Czapla-Masztafiak, W. M. Kwiatek (Inst. of Nucl. Phys. PAN (Krakow) and M. Vogt (University of Bremen) [Cu4(PCP)3]+ Jet Jungfrau 4.5M Jungfrau 4.5 M XES P Kα Photon in kev X-ray Kα ev UV Laser Phosphorescence Jet Kα ev

21 Aramis beamline courtesy: U. Flechsig and R. Follath Flat Offset Mirrors from JTEC (2) and Zeiss (4) Size : 770 x 80 x 50 (80) mm 3 Optical surface : 630 x 30 mm 2 Height error : < 6 nm rms ** **) within noise level of PSI metrology Microroughness : < 0.2 nm Coatings : SiC/B 4 C, Si, Mo/B 4 C S. Spielmann-Jäggi by Offset mirror measurements

22 First Mirror for ARAMIS PSI courtesty Rolf Follath & Uwe Flechsig -PV (300mm): 2.6 nm (3) -Figure error: 0.5 nm rms (0.6) (full-length) M-201 and Uwe Flechsig

23 Fluence Beam size r (r) 2 r (0) r ' z 2 Peak fluence ˆ EP ( z) 2 ( z) r ( E p : pulse energy ) Max. dose absorbed by atoms ˆ ( z) Fluence is alway lower than damage threshold of B 4 C Iron or steel critical below 50 m

24 Mirror coatings for Aramis B 4 C / SiC on Si Low-Z materials 10 nm B 4 C 36 nm SiC Si bulk B 4 C / Mo on Si Mo is Mid-Z material 15 nm B 4 C 20 nm Mo Si bulk SiC shifts the cut off to higher energies B 4 C covers absorption edge Mo is well known multilayer material 1 No harmonic rejection in working energy range Extend range to ev (3rd harmonic), 1 M. Störmer, SPIE 7077, (2008)

25 Characterisation of Bilayer Mo / B 4 C bilayer Sample 15 nm B 4 C 20 nm Mo Si bulk

26 Coating of offset mirrors First stripe: SiC + top B 4 C End of June 2016 Run ID T664 coating area above width: mm (or mm) (uncoated silicon below) Label Second stripe: Mo + top B 4 C Beginning of July 2016 Run ID T668 coating area above width: mm (or mm) (first stripe below) Label Courtesy, M. Stoermer, HzG Geesthacht

27 XRR-measurement of Mo/B 4 C T668 Courtesy, M. Stoermer, HzG Geesthacht

28 Reflective optics λ=1 Å Total reflecting mirrors θ small angle ->long mirrors ρ: electron density, r e = m Critical angle c r e Θ = 4 mrad Multilayer Θ = 9 mrad θ large angle ->short mirrors Multilayers only in narrow energy band Incidence angle only a few mrad

29 Graded Multilayer φ θ 1 θ 2 θ 1 Mirror 0 z Bragg equation sin ( z) 2d( z) Multilayer gradient: d( z) d0(1 B1 z B2z 2...) Graded multilayer fills the numerical aperture! (deg) Mirror1 (HFM): B 1 = / mm Mirror2 (VFM): B 1 = / mm