Femtosecond time-delay holography Henry Chapman Centre for Free-Electron Laser Science - DESY Lawrence Livermore National Laboratory

Transcription

1 Femtosecond time-delay holography Henry Chapman Centre for Free-Electron Laser Science - DESY Lawrence Livermore National Laboratory Henry.Chapman@desy.de

2 Isaac Newton Opticks 1704

3 Newton was the first person to describe interference 3

4 Newton was the first person to describe interference 4

5 Newton s dusty mirror was explained by Thomas Young 100 years later 5

6 Newton s dusty mirror was explained by Thomas Young 100 years later 5

7 Newton s dusty mirror was explained by Thomas Young 100 years later 2l 2l cos θ = Nλ 2l(1 cos θ) =Nλ lθ 2 = Nλ θ 5

8 6

9 6

10 Our diffraction camera can measure forward scattering close to the direct soft-x-ray FEL beam No pinhole or monochromator ~5x10 12 photons/ 100 ev Soft edge prevents any scatter from the hole Multilayer reflectivity is uniform across the 30 to 60 gradient 7

11 We invented a new method called femtosecond timedelay holography 30 fs pulse (9 µm long) Prompt diffraction Delayed diffraction Time delay 2 l / c H. Chapman et al., Nature (2007)

12 We invented a new method called femtosecond timedelay holography 30 fs pulse (9 µm long) object reference Prompt diffraction Delayed diffraction Time delay 2 l / c H. Chapman et al., Nature (2007)

13 X-ray free-electron lasers may enable atomicresolution imaging of biological macromolecules One pulse, one measurement Particle injection XFEL pulse Noisy diffraction pattern R. Neutze et al, Nature 406 (2000) Combine measurements Classification Averaging G. Huldt et al, J. Struct. Biol 144 (2003) Orientation Reconstruction J. Miao, Hodgson, Sayre, PNAS 98 (2001)

14 Coulomb explosion of Lysozyme 50 fs 4x10 14 photons/µm 2 12 kev Radiation damage affects atomic scattering factors and atomic positions Neutze, R., Wouts, R., van der Spoel, D., Weckert, E. Hajdu, J. (2000) Nature 406,

15 Coulomb explosion of Lysozyme 20 fs 4x10 14 photons/µm 2 12 kev Radiation damage affects atomic positions and atomic scattering factors Neutze, R., Wouts, R., van der Spoel, D., Weckert, E. Hajdu, J. (2000) Nature 406,

16 Temperature (ev) We model the response of matter illuminated by intense X-ray pulses as a hot plasma Hot Plasma LCLS FLASH Warm Dense Matter strongly coupled Ion density (10 22 /cm 3 ) (2,4) (2,3) (2,2) Carbon (1,2) (2,0)(1,0) (2,1) (1,1) (1,4) (1,3) time (fs) (k,l) =(# K-shell, # L-shell) electrons black = neutral carbon blue = valence ionization red = inner shell ionization 10-2 degenerate Density (g/cm 3 ) S. Hau-Riege et al, Phys Rev E 69, (2004) Hydrodynamic continuum model for the atomic motion and the ionization processes: Allows for trapping and secondary effects (such as inverse Bremsstralung, 3-body recombination) Damage is dominated by ionization at short times

17 We invented a new method called femtosecond timedelay holography 30 fs pulse (9 µm long) Prompt diffraction Delayed diffraction Time delay 2 l / c H. Chapman et al., Nature (2007)

18 We invented a new method called femtosecond timedelay holography 30 fs pulse (9 µm long) object reference Prompt diffraction Delayed diffraction Time delay 2 l / c H. Chapman et al., Nature (2007)

19 First EUV-FEL experiments show that structural information can be obtained before destruction During 30 fs pulse (10 14 W cm -2 ) 32 nm wavelength Si/C multilayer Reflectance (%) fs pulse reflectivity at 32nm 16% 100% increasing fluence Low-fluence Reflectivity unchanged Multilayer d spacing not changed by more than 0.3 nm Angle of incidence (degrees) After pulse Plasma forms, layers ablate Nomarski micrograph of crater 400 nm 40 micron 5 µm 10 µm S.P. Hau-Riege et al., PRL (2007) 10 µm 5 µm 14

20 Initial high-angle diffraction shows no change in structure of particles greater than 12 nm Diffracted intensity (arb. units) Resolution length (nm) Fluence 100% 30% 10% 15º Scattering angle (degrees) 15

21 Initial high-angle diffraction shows no change in structure of particles greater than 12 nm Diffracted intensity (arb. units) Resolution length (nm) Fluence 100% 30% 10% 15º Scattering angle (degrees) 15

22 Our VUV hydrodynamic code shows that latex spheres start exploding in ~ 2 ps λ = 32 nm, J/cm 2 26 fs 130 fs 800 fs 2.3 ps Density (g/cm 3 ) Electron temperature (ev) Ion temperature (ev) S. Hau-Riege et al, Phys Rev E (2007) 16

23 First demonstration of time-delay holography with 3 fs time resolution indicates the particle explosion Intensity (counts) raw smoothed q (µm -1 ) Single shot ultrafast time-delay X-ray hologram, with 300 fs delay The dusty mirror experiment

24 We interferometrically measure the change in optical density of the particle at short delays d 1 d 2 Object, phase change of ϕ reference Fitting the ring radii gives l and ϕ Rings occur when l +ϕ+d 1 =d 2 +Nλ l Phase shift (degrees) Δn Delay (fs) W/cm 2

25 We interferometrically measure the change in optical density of the particle at short delays 26 fs 130 fs 800 fs 2.3 ps Electron temp. (ev) nm 10 5 nm Delay (fs) Phase shift (degrees)30 ΔR W/cm 2

26 The explosion is in good agreement with our hydrodynamic model Experiments Calculation Intensity (arb. units) ps 7.8 ps 3.2 ps ps 7.8 ps 3.2 ps q (µm -1 ) The structure factor narrows, showing the particle exploding The lower resolution shape of the explosion is different than expected This is the first high-resolution observation of particle explosions H. Chapman et al., Nature (2007) 20

27 The explosion is in good agreement with our hydrodynamic model Experiments Calculation Intensity (arb. units) ps 7.8 ps 3.2 ps ps 7.8 ps 3.2 ps q (µm -1 ) The structure factor narrows, showing the particle exploding The lower resolution shape of the explosion is different than expected This is the first high-resolution observation of particle explosions H. Chapman et al., Nature (2007) 20

28 We have tried a new time-delay geometry in which the prompt diffraction is blocked object aperture detector multilayer mirror delay 21

29 This geometry can be extended to shorter wavelengths sample injector or sample stage K-B focusing Reflector (e.g. InSb) FEL CCD Reflection of InSb 111 at 1.66 kev (7.48Å) The reflector will pass prompt diffraction for angles <23 mrad. This will give enough fringes to determine the delay.

30 This geometry can be extended to shorter wavelengths sample injector or sample stage K-B focusing Reflector (e.g. InSb) FEL CCD Reflection of InSb 111 at 1.66 kev (7.48Å) The reflector will pass prompt diffraction for angles <23 mrad. This will give enough fringes to determine the delay. 61% reflectivity 23 mrad Darwin width Bandwidth: 0.04%

31 This geometry can be extended to shorter wavelengths using grazing incidence K-B focusing CCD FEL sample injector or sample stage grazing incidence

32 Summary The back-reflection geometry allows you to probe the evolution of FEL-matter interactions with sub-fs resolution and for timescales of 10 fs to >>100 ps Holographic rings give time delay change in phase (change in optical constants or path) Diffraction gives structural information (before and after) This could be used for studying: Coulomb explosions in clusters Evolution of optical constants in plasmas and warm dense matter Effectiveness of tampers in slowing down FEL-induced explosions High-field ionization 24

33 Acknowledgments LLNL: Uppsala: SLAC: LBNL: DESY: TU Berlin: CFEL: Anton Barty, Matthias Frank, Stefan Hau-Riege, Richard Lee, Richard London, Urs Rohner, Eberhard Spiller, Abraham Szöke, Bruce Woods Janos Hajdu, Magnus Bergh, Nicusor Timeneau, Bianca Iwan, Gösta Huldt, Calle Caleman, Marvin Seibert, Erik Marklund, Filipe Maia Sebastien Boutet, Michael Bogan Stefano Marchesini, David Shapiro Thomas Tschentscher, Elke Plönjes, Marion Kulhman, Rolf Treusch, Stefan Dusterer, Jochen Schneider Thomas Möller, Christof Bostedt Saša Bajt