First-, second- and third-order correlation function in time-resolved X-ray diffraction experiments

2004 ◽  
Vol 37 (3) ◽  
pp. 445-450 ◽  
Author(s):  
Simone Techert
Keyword(s):  
Structural Changes ◽  
X Rays ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Third Order ◽  
Time Resolved ◽  
Pump Probe ◽  
X Ray ◽  
Laser Systems ◽  
Laser Sources

In the past decade, sustained progress has been made in the field of time-resolved X-ray diffraction and photocrystallography. Laser systems have been developed rapidly, and the combination of pulsed laser sources with pulsed X-ray sources, particularly by using synchrotron X-ray radiation and X-rays generated by plasma sources, has made the application of pump-probe schemes routine. So far, however, most studies have been focused on two questions: (i) the refinement of structural changes during the course of a reaction, and (ii) possible relations between transient structural changes and the intermediates found by optical spectroscopy. In this work, a kinetic description for different time laws in time-resolved X-ray diffraction experiments is derived in the framework of time-dependent correlation functions. The derived time laws were applied to time-resolved studies on a [2+2] photodimerization and a reversible reaction undergoing structural reorganization.

scholarly journals Laue diffraction and time-resolved crystallography: a personal history

2019 ◽  
Vol 377 (2147) ◽  
pp. 20180243 ◽  
Author(s):  
Keith Moffat
Keyword(s):  
Storage Ring ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Laue Diffraction ◽  
Time Resolved ◽  
Pump Probe ◽  
X Ray ◽  
Historical View ◽  
Laser Sources ◽  
Diffraction Patterns

A personal, historical view is presented of Laue X-ray diffraction and its application to time-resolved studies of dynamic processes, largely in light-sensitive biological systems. In Laue diffraction, a stationary crystal is illuminated by a polychromatic X-ray source. Laue diffraction has inherent complications largely absent in monochromatic diffraction, and consequently fell into disuse for quantitative structure determination. However, the advent of naturally polychromatic, intense, pulsed storage ring X-ray sources in the 1970s led to re-examination at Daresbury and elsewhere of its underlying principles. Laue diffraction has been successfully applied at storage ring sources to time-resolved, pump–probe crystallographic studies, whose exposure time and time resolution were progressively reduced from minutes to seconds, milliseconds, nanoseconds and 100 ps. Most recently, hard X-ray free electron laser sources have been used to generate narrow bandpass Laue diffraction patterns. The femtosecond X-ray pulses from such sources are completely destructive, generate only one diffraction pattern per tiny crystal and have unusual properties. However, they too are being applied to time-resolved crystallography to explore, for example, isomerization and rapid tertiary structural changes on the chemical, femtosecond timescale. This article is part of the theme issue ‘Fifty years of synchrotron science: achievements and opportunities’.

scholarly journals First steps towards time-resolved 'in-house' X-ray diffraction experiments

2014 ◽  
Vol 70 (a1) ◽  
pp. C775-C775 ◽  
Author(s):  
Radoslaw Kaminski ◽  
Jason Benedict ◽  
Elzbieta Trzop ◽  
Katarzyna Jarzembska ◽  
Bertrand Fournier ◽  
...  
Keyword(s):  
Excited State ◽  
Time Resolution ◽  
Structural Changes ◽  
Laser Pulses ◽  
High Repetition Rate ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
Time Resolved ◽  
X Ray ◽  
Ligand Charge Transfer

High-intensity X-ray sources, such as synchrotrons or X-ray free electron lasers, providing up to 100 ps time-resolution allow for studying very short-lived excited electronic states in molecular crystals. Some recent examples constitute investigations of Rh...Rh bond shortening,[1] or metal-to-ligand charge transfer processes in CuI complexes.[2] Nevertheless, in cases in which the lifetime of excited state species exceeds 10 μs it is now possible, due to the dramatic increase in the brightness of X-ray sources and the sensitivity of detectors, to use laboratory equipment to explore structural changes upon excitation. Consequently, in this contribution we present detailed technical description of the 'in-house' X-ray diffraction setup allowing for the laser-pump X-ray-probe experiments within the time-resolution at the order of 10 μs or larger. The experimental setup consists of a modified Bruker Mo-rotating-anode diffractometer, coupled with the high-frequency Nd:YAG laser (λ = 355 nm). The required synchronization of the laser pulses and the X-ray beam is realized via the optical chopper mounted across the beam-path. Chopper and laser capabilities enable high-repetition-rate experiments reaching up to 100 kHz. In addition, the laser shutter is being directly controlled though the original diffractometer software, allowing for collection of the data in a similar manner as done at the synchrotron (alternating light-ON & light-OFF frames). The laser beam itself is split into two allowing for improved uniform light delivery onto the crystal specimen. The designed setup was tested on the chosen set of crystals exhibiting rather long-lived excited state, such as, the Cu2Br2L2 (L = C5H4N-NMe2) complex, for which the determined lifetime is about 100 μs at 90 K. The results shall be presented. Research is funded by the National Science Foundation (CHE1213223). KNJ is supported by the Polish Ministry of Science and Higher Education through the "Mobility Plus" program.

scholarly journals Time-resolved X-ray diffraction study of structural changes associated with the photocycle of bacteriorhodopsin.

1991 ◽  
Vol 10 (3) ◽  
pp. 521-526 ◽  
Author(s):  
M. H. Koch ◽  
N. A. Dencher ◽  
D. Oesterhelt ◽  
H. J. Plöhn ◽  
G. Rapp ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray

scholarly journals Observation of Transient Structural Changes on Hydrogen Absorption Process of LaNi4.75Sn0.25 by Time Resolved X-Ray Diffraction

2015 ◽  
Vol 79 (3) ◽  
pp. 124-130 ◽  
Author(s):  
Akihiko Machida ◽  
Kensuke Higuchi ◽  
Yoshinori Katayama ◽  
Kouji Sakaki ◽  
Hyunjeong Kim ◽  
...  
Keyword(s):  
Hydrogen Absorption ◽  
Structural Changes ◽  
Absorption Process ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray

scholarly journals Experimental and numerical study of ultra-short laser-produced collimated Cu Kα X-ray source

2017 ◽  
Vol 35 (3) ◽  
pp. 442-449 ◽  
Author(s):  
R. Rathore ◽  
V. Arora ◽  
H. Singhal ◽  
T. Mandal ◽  
J.A. Chakera ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Numerical Study ◽  
Low Cost ◽  
Laser Pulses ◽  
Photon Flux ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Short Laser Pulses

AbstractKα X-ray sources generated from the interaction of ultra-short laser pulses with solids are compact and low-cost source of ultra-short quasi-monochromatic X-rays compared with synchrotron radiation source. Development of collimated ultra-short Kα X-ray source by the interaction of 45 fs Ti:sapphire laser pulse with Cu wire target is presented in this paper. A study of the Kα source with laser parameters such as energy and pulse duration was carried out. The observed Kα X-ray photon flux was ~2.7 × 108 photons/shot at the laser intensity of ~2.8 × 1017 W cm−2. A model was developed to analyze the observed results. The Kα radiation was coupled to a polycapillary collimator to generate a collimated low divergence (0.8 mrad) X-ray beam. Such sources are useful for time-resolved X-ray diffraction and imaging studies.

Structural changes during activation of frog muscle studied by time-resolved X-ray diffraction

1986 ◽  
Vol 188 (3) ◽  
pp. 325-342 ◽  
Author(s):  
M. Kress ◽  
H.E. Huxley ◽  
A.R. Faruqi ◽  
J. Hendrix
Keyword(s):  
Structural Changes ◽  
Frog Muscle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray

scholarly journals XPP: X-ray Pump Probe station at BESSY II

2016 ◽  
Vol 2 ◽  
Author(s):  
Matthias Reinhardt ◽  
Wolfram Leitenberger
Keyword(s):  
Soft Matter ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Pump Probe ◽  
X Ray ◽  
Experimental Station

The X-ray Pump-Probe (XPP) experimental station predominantly aims at investigating hard and soft matter under a broad range of ambient conditions using time-resolved X-ray diffraction.

scholarly journals The High Pressure Behavior of Galenobismutite, PbBi2S4: A Synchrotron Single Crystal X-ray Diffraction Study

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 210 ◽  
Author(s):  
Paola Comodi ◽  
Azzurra Zucchini ◽  
Tonci Balić-Žunić ◽  
Michael Hanfland ◽  
Ines Collings
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Structural Changes ◽  
Calcium Ferrite ◽  
X Ray Diffraction ◽  
Third Order ◽  
Electron Pairs ◽  
X Ray ◽  
Cation Sites ◽  
Murnaghan Equation

High-pressure single-crystal synchrotron X-ray diffraction data for galenobismutite, PbBi2S4 collected up to 20.9 GPa, were fitted by a third-order Birch-Murnaghan equation of state, as suggested by a FE-fE plot, yielding V0 = 697.4(8) Å3, K0 = 51(1) GPa and K’ = 5.0(2). The axial moduli were M0a = 115(7) GPa and Ma’ = 28(2) for the a axis, M0b = 162(3) GPa and Mb’ = 8(3) for the b axis, M0c = 142(8) GPa and Mc’ = 26(2) for the c axis, with refined values of a0, b0, c0 equal to 11.791(7) Å, 14.540(6) Å 4.076(3) Å, respectively, and a ratio equal to M0a:M0b:M0c = 1.55:1:1.79. The main structural changes on compression were the M2 and M3 (occupied by Bi, Pb) movements toward the centers of their respective trigonal prism bodies and M3 changes towards CN8. The M1 site, occupied solely by Bi, regularizes the octahedral form with CN6. The eccentricities of all cation sites decreased with compression testifying for a decrease in stereochemical expression of lone electron pairs. Galenobismutite is isostructural with calcium ferrite CaFe2O4, the suggested high pressure structure can host Na and Al in the lower mantle. The study indicates that pressure enables the incorporation of other elements in this structure, increasing its potential significance for mantle mineralogy.

scholarly journals X-rays only when you want them: optimized pump–probe experiments using pseudo-single-bunch operation

2015 ◽  
Vol 22 (3) ◽  
pp. 729-735 ◽  
Author(s):  
M. P. Hertlein ◽  
A. Scholl ◽  
A. A. Cordones ◽  
J. H. Lee ◽  
K. Engelhorn ◽  
...  
Keyword(s):  
Laser Excitation ◽  
Ccd Camera ◽  
Single Shot ◽  
X Rays ◽  
Time Resolved ◽  
Pump Probe ◽  
Charge Coupled Device ◽  
X Ray ◽  
X Ray Absorption ◽  
Sample Damage

Laser pump–X-ray probe experiments require control over the X-ray pulse pattern and timing. Here, the first use of pseudo-single-bunch mode at the Advanced Light Source in picosecond time-resolved X-ray absorption experiments on solutions and solids is reported. In this mode the X-ray repetition rate is fully adjustable from single shot to 500 kHz, allowing it to be matched to typical laser excitation pulse rates. Suppressing undesired X-ray pulses considerably reduces detector noise and improves signal to noise in time-resolved experiments. In addition, dose-induced sample damage is considerably reduced, easing experimental setup and allowing the investigation of less robust samples. Single-shot X-ray exposures of a streak camera detector using a conventional non-gated charge-coupled device (CCD) camera are also demonstrated.

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