Ultrafast laser-plasma sources for 50-fs hard x-ray pulse generation and laser pump x-ray probe measurements of solvated transition metal complexes

Transcription

1 Ultrafast laser-plasma sources for 50-fs hard x-ray pulse generation and laser pump x-ray probe measurements of solvated transition metal complexes ERL Workshop, Cornell University June 2006 C. Rose-Petruck Department of Chemistry, Brown University, Providence, R.I.

2 Outline Ultrafast XANES of Fe(CN) fs laser-plasma x-ray sources Ultrafast x-ray sources and Cornell ERL-II experiments

3 Outline Ultrafast XANES of Fe(CN) fs laser-plasma x-ray sources Ultrafast x-ray sources and Cornell ERL-II experiments

4 Multiple scattering paths of IPC-Bz at 0 Kelvin Path 8: 153% Path 7: 123% Path 1: 100% Path 6: 25% Path 23: 11% Path 31: 9% Path 20: 9% Path 33: 8% Path 27: 4% Path 35: 4% Path 28: 3% Path 5: 2%

5 Excited state chemistry of iron hexacyanide in water λ - 266nm Fe(CN) 4-6 Fe(CN) 3-+ e- CTTS 6 aq CTTS Fe(CN) hν λ nm Fe(CN) 4-6 +H 2 O 3- ( Fe(CN) 5 H 2 O) + CN - Photoaquation Excitation photon wavelength < 270 nm: Charge Transfer To Solvent Excitation photon wavelength < 400 nm: Photoaquation

6 NP: 10FC16PB.5 OS: 2pcs, Lasermetrics Ultrafast laser for laboratory-based plasma x-ray sources F=500mm Main laser beam for x-ray generation X-ray lens Overlap of laser and x-ray beams in liquid sample jet Pump laser beam Si(111) double crystal spectrometer CCD camera Nd:YVO 4 Laser pulse: 800 nm, 40 fs, 4 mj, 5 khz Average compressed power: 20W Laser intensity: ~ W/cm 2

7 Ultrafast laser-driven XAFS spectrometer Honeywell CCD GC-135E24-G Si(111) double crystal spectrometer Overlap of laser and x-ray beams in liquid sample jet CCD camera X-ray lens F=500mm Pump laser beam Main laser beam for x-ray generation

8 X-ray emission spectrum of 2-kHz source kev range 9 ph π s Cu K 10 α 4 ph π s X-ray flux [ ph / (s 4π sr ev) ] Fe-Kα Fe-Kβ V-Kα Cu-Kα Zn-Kα Cu-Kβ Zn-Kβ Iron K-edge X-ray photon energy [ kev ]

9 Laser plasma x-radiation imaged into sample by x-ray lens Bremsstrahlung : 5x10 Cu K α : 2x photons s photons s 1keV

10 Ultrafast laser-driven XAFS spectrometer Honeywell CCD GC-135E24-G Si(111) double crystal spectrometer Overlap of laser and x-ray beams in liquid sample jet CCD camera X-ray lens F=500mm Pump Static Background Fe K β Fe K-edge Pump laser beam Main laser beam for x-ray generation

11 UXANES at 30 ps, 0 ps, and +40 ps after photoexcitation ps ~0 ps ps 1 Normalized absorbance NSLS-X11B X 8eV: Fe(CN) 6 4- Fe-K β Peak centroids: +40 ps: ev ~0 ps: ev -30 ps: ev X-ray photon energy [ev]

12 Radial Fe-ligand bond lengths increase of Fe(CN) pm +10 pm [Fe(CN) 6 ] 4- [Fe(CN) 5 H 2 O] 3- [Fe 2 (CN) 10 ] 6- Normalized absorbance X-ray photon energy [ev]

13 Outline Ultrafast XANES of Fe(CN) fs laser-plasma x-ray sources Ultrafast x-ray sources and Cornell ERL-II experiments

14 New liquid metal x-ray source

15 4 diameter deformable mirror for focus optimization Fused silica membrane, 200 µm thick Piezo actuators Ceramic base plate Printed circuit board 200 μm

16 X-ray emission spectrum of Hg-source 1.E+11 1 kev range ph 4π s X-ray source flux [ ph / (s 4π sr kev) ] 1.E+10 1.E+09 1.E+08 Hg-L α1,2 Hg-L β1,2 Hg-L γ 1.E X-ray photon energy [ kev ]

17 Numerical modeling of laser-produced x-ray emission

18 X-ray absorption in Iron and Mercury Fe K-edge Absorption lengths: 6.5 kev: 19 μm 7.2 kev: 3.1 μm 7.2 kev: 2.7 μm Fe 6.5 kev

19 Similar x-ray yields for Fe and 7.2 kev 100 fs laser L/λ = 0.2 Highest x-ray yield at medium laser

20 Temporal x-ray pulse shape from Iron and Mercury W/cm fs L/λ = 0.2 solid lines: generated photons dashed lines: emitted photons

21 50 fs x-ray pulses are possible 4 x W/cm 2, 100 fs L/λ = 0.2 Mercury 7.2 kev 50 fs FWHM

22 The continuum pulse can be shorter than the laser pulse 100 fs L/λ = 0.2

23 X-ray yield and pulsewidth for Fe and Hg target

24 Outline Ultrafast XANES of Fe(CN) fs laser-plasma x-ray sources Ultrafast x-ray sources and Cornell ERL-II experiments

25 Comparison of laboratory-based hard x-ray sources X-ray flux (ph/4π sr s) A. Rousse, et al, Phys. Rev. E, 50, 2200 (1994) D. Eder, et al, Appl. Phys. B, 70, 211 (2000) R. Tompkins, et al, Rev. Sci. Instrum. 69, 3113 (1998) M. Yoshida, et al, Appl. Phys. Lett (1998) B. Soom, et al, J. Appl. Phys. 74, 5372 (1993) Ch. Ziener, et al, Phys. Rev. E 65, (2002) T. Guo, et al, Rev. Sci. Instrum. 72, 41 (2001) Z. Jiang, et al, Phys Plasmas, 2, 1702, (1995) T. Feurer, at al, Appl. Phys. B, 72, 15, (2001) A. Egbert, et al, Appl. Phys. Let., 81, 2328 (2002) Y. Hironaka, et al, J. Appl. Phys., 74, 165 (1999) G. Korn et al, Opt. Lett. 27, (2002) This work 250 khz, 3 μj, 160 fs, X-ray diode, Cu anode 1 khz, 30 μj, 120 fs Hz, 13 mj, 1.3 ps, 4x10 15 W/cm 2, Al coat on Si 10 Hz, 1.5 mj, 100 fs, 3x10 16 W/cm 2, Al estgimated future flux: 2 khz, 4.25 mj, 40 fs, 3x10 18 W/cm 2, liquid Hg 2 khz, 4.25 mj, 40 fs, W/cm 2, Brass wire 1 khz, 1.8 mj, 100 fs, 10 Hz, 200 mj, 200 fs, W/cm 2, Cu slab 10 Hz, 60 mj, 42 fs, W/cm 2, Cu disk 3x10 16 W/cm 2, liquid Ga 20 Hz, 80 mj, 35 fs, W/cm 2, Cu wire 10 Hz, 60 mj, 80 fs, 5x10 17 W/cm 2, Si 10 Hz, 200 mj, 42 fs, 3x10 17 W/cm 2, 4th shot, Cu 10 Hz, 240 mj, 60 fs, W/cm 2, Co 1st shot Hz, 900 mj, 300 fs, 4x10 18 W/cm 2, Ta 1 khz, 0.5 mj, 100 fs liquid jet Cu(NO) Laser peak power (W)

26 Comparison of x-ray sources X-ray absorption spectrometer with Repetition rate [khz] Pulse length [ps] Average x-ray flux [ph / s] Peak x-ray flux [ph / s ps] 12 kw rotating anode tube c.w. 6 x x 10-3 APS, sector 1kHz pump laser rep. rate, special-timing-mode 1 80 unfocused: 2x10 9 unfocused: 2 x 10 7 KB-focused: 5x10 7 KB-focused: 5 x 10 5 APS, sector 1kHz pump laser rep. rate, special-timing-mode At sample Tabletop ultrafast x-ray sources (8-15 W) At detector Old Source: 10 6 New Source: crystal optics: Old Source: 100 New Source: crystal optics: 10 6 Old Source: 10 7 New Source: crystal optics: Old Source: 1000 New Source: crystal optics: 10 7

27 Prospective ERL parameters

28 The I 2 -reflectron B. Kohler, J.L. Krause, F. Ráksi, C. Rose-Petruck, R.M. Whitnell, K.R. Wilson, V.V. Yakovlev, Y. Yan, S. Mukamel, J. Phys. Chem. 97, (1993)

29 I-I distance probability distributions optimal chirp 20 I-I distance [pm] positive chirp Ψ Ψ* time delay [fs]

30 Simulated diffraction pattern for Cu-K α x-ray pulses 20 optimal chirp diffraction angle [degree] positive chirp counts time delay [fs]

31 Funding National Science Foundation, Chemistry Department of Energy, BES Army Medical Res. and Material Command Argonne National Laboratory Andrew W. Mellon Foundation Research Corporation

32 Nuclear motions and ultrafast x-ray diffraction off I 2 diffraction angle [degree] I-I distance [pm] optimal chirp time delay [fs]

33 Calculated XAFS spectrum of NiCO 4 X-ray photon energy [kev] Norm. Absorption [a.u.]

34 S/N calculation for EXAFS of solute at ultrafast Cornell ERL-II Liquid beam parameters Results for sample excitation Beam thickness [um] 500 # of pump photons / pulse 1.34E+11 Pumped beam width (time axis) [mm] 0.01 Transmitted pulse energy [mj] 1.78E-05 Pumped beam height (wavelength axis) [mm] 0.01 Absorbed pulse energy [mj] 8.22E-05 Pumped beam height restriction factor (for measuring a restricted wavelength range with increased pump laser fluence) [%] % Transmittance 17.78% Beam area [mm²] Absorbance 82.22% Solute number in "Solutes" Worksheet 4 # of absorbed pump photons 1.11E+11 Solute concentration [mol / L] Pumped beam volume [mm^3] Solute name Ni(CO)4 Concentration of exited molecules [mol / L] 3.67E-03 Molar absorption coefficient [L / (mol cm)] 500 Concentration of unexcited molecules [mol / L] 2.63E-02 Pump wavelength [nm] 267 Excitation fraction [%] 12.23% Pump pulse energy [mj] 1.E-04 Pump repetition rate [khz] 1000 Average laser power [W] 100 Pump pulse fluence [mj / cm²] Pump pulselength [fs] 100 Pump pulse intensity [W / cm²] 1.0E+12 Solvent parameters Results for transmission detection X-ray transmission by solvent [%] 45.8% X-ray transmission by solvent [%] 45.83% Solute parameters X-ray absorbance by excited molecules [%] 0.35% X-ray absorbance by unexcited molecules [%] 2.50% Edge type Ni-K Total x-ray absorbance due to solute molecules [%] 2.85% Post-edge x-ray mass absorption coefficient [cm² / g] Total x-ray transmittance due to solute molecules [%] 97.15% Pre-edge x-ray mass absorption coefficient [cm² / g] Transmission modulation due to exited molecules 0.35% Molar mass of x-ray absorbing solute atom [g / mol] Total x-ray transmittance due to solute and solvent [%] 44.52% EXAFS modulation depth [%] 5.00% Required accuracy of measurement 8.72E-06 Accuracy of measurement for excited solutes [%] 5.00% Min. S/N of x-ray measurement X-ray fluorescence efficiency [%] 30.00% Min. required # of x-ray ph. on sample / wave-time step 5.91E+10 Min. required # of x-ray ph. on sample / (all times full spectral range) 5.91E+15 X-ray spectrometer parameters Total data acquisition time (all times 1000eV) [s] Detection efficiency for transmission detection [%] 50.00% Total data acquisition time (all times 1000eV) [min] Detection efficiency for fluorescence detection [%] 10.00% Number of wave-channels measured simultaneously for full spectral range 1 # of x-ray photons on sample [1 / ev s] 7.65E+11 Number of time-channels measured simultaneously 1 Desired spectral resolution (i.e. wave step) [ev] 1 Total data acquisition time [h : m : s] 4:40:46 Numer of desired time-steps 100 Spectral range over which the measurements are done [ev] 1000

35 Acknowledgments: Dr. Christian Reich Dr. Chris Laperle Dr. Taewoo Lee Dr. Yan Jiang Xiaodi Li Brian Ahr Joshua Lessing Emma Welch Margaret Grant Frank Benesch Dr. Claude Bailat Dr. Guohua Cao Prof. Gerald Diebold Theron Hamilton Dr. Philip Wintermeyer, M.D., Dr. Stephan Gehring, M.D., Liver Research Center, Brown Medical School Prof. Jack R. Wands, M.D., Liver Research Center, Brown Medical School, Rhode Island Hospital