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 ◽  
...  

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.

2021 ◽  
Vol 28 (3) ◽  
Author(s):  
Matthias Rössle ◽  
Wolfram Leitenberger ◽  
Matthias Reinhardt ◽  
Azize Koç ◽  
Jan Pudell ◽  
...  

The time-resolved hard X-ray diffraction endstation KMC-3 XPP for optical pump/X-ray probe experiments at the electron storage ring BESSY II is dedicated to investigating the structural response of thin film samples and heterostructures after their excitation with ultrashort laser pulses and/or electric field pulses. It enables experiments with access to symmetric and asymmetric Bragg reflections via a four-circle diffractometer and it is possible to keep the sample in high vacuum and vary the sample temperature between ∼15 K and 350 K. The femtosecond laser system permanently installed at the beamline allows for optical excitation of the sample at 1028 nm. A non-linear optical setup enables the sample excitation also at 514 nm and 343 nm. A time-resolution of 17 ps is achieved with the `low-α' operation mode of the storage ring and an electronic variation of the delay between optical pump and hard X-ray probe pulse conveniently accesses picosecond to microsecond timescales. Direct time-resolved detection of the diffracted hard X-ray synchrotron pulses use a gated area pixel detector or a fast point detector in single photon counting mode. The range of experiments that are reliably conducted at the endstation and that detect structural dynamics of samples excited by laser pulses or electric fields are presented.


2014 ◽  
Vol 70 (a1) ◽  
pp. C775-C775 ◽  
Author(s):  
Radoslaw Kaminski ◽  
Jason Benedict ◽  
Elzbieta Trzop ◽  
Katarzyna Jarzembska ◽  
Bertrand Fournier ◽  
...  

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.


1994 ◽  
Vol 38 ◽  
pp. 21-33
Author(s):  
I. V. Tomov ◽  
P. Chen ◽  
P. M. Rentzepis

Abstract We report the development of a novel, pulsed x-ray diffraction system with picosecond time resolution. The system has been used to study the heat transport in gold, platinum and silicon crystals heated by 10 ps, 193 nm laser pulses. Further developments and applications of time resolved picosecond x-ray diffraction are discussed.


2019 ◽  
Vol 9 (22) ◽  
pp. 4878 ◽  
Author(s):  
Jae-Hun Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
Hong Joo Kim ◽  
Phan Quoc Vuong ◽  
...  

X-Ray radiation sensors that work at room temperature are in demand. In this study, a novel, low-cost real-time X-ray radiation sensor based on SnO2 nanowires (NWs) was designed and tested. Networked SnO2 NWs were produced via the vapor–liquid–solid technique. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM) analyses were used to explore the crystallinity and morphology of synthesized SnO2 NWs. The fabricated sensor was exposed to X-rays (80 kV, 0.0–2.00 mA) and the leakage current variations were recorded at room temperature. The SnO2 NWs sensor showed a high and relatively linear response with respect to the X-ray intensity. The X-ray sensing results show the potential of networked SnO2 NWs as novel X-ray sensors.


Author(s):  
Jeongho Kim ◽  
Kyung Hwan Kim ◽  
Jae Hyuk Lee ◽  
Hyotcherl Ihee

In recent years, the time-resolved X-ray diffraction technique has been established as an excellent tool for studying reaction dynamics and protein structural transitions with the aid of 100 ps X-ray pulses generated from third-generation synchrotrons. The forthcoming advent of the X-ray free-electron laser (XFEL) will bring a substantial improvement in pulse duration, photon flux and coherence of X-ray pulses, making time-resolved X-ray diffraction even more powerful. This technical breakthrough is envisioned to revolutionize the field of reaction dynamics associated with time-resolved diffraction methods. Examples of candidates for the first femtosecond X-ray diffraction experiments using highly coherent sub-100 fs pulses generated from XFELs are presented in this paper. They include the chemical reactions of small molecules in the gas and solution phases, solvation dynamics and protein structural transitions. In these potential experiments, ultrafast reaction dynamics and motions of coherent rovibrational wave packets will be monitored in real time. In addition, high photon flux and coherence of XFEL-generated X-ray pulses give the prospect of single-molecule diffraction experiments.


2021 ◽  
Vol 118 (22) ◽  
pp. e2105046118
Author(s):  
Stefano M. Cavaletto ◽  
Daniel Keefer ◽  
Jérémy R. Rouxel ◽  
Flavia Aleotti ◽  
Francesco Segatta ◽  
...  

The outcomes and timescales of molecular nonadiabatic dynamics are decisively impacted by the quantum coherences generated at localized molecular regions. In time-resolved X-ray diffraction imaging, these coherences create distinct signatures via inelastic photon scattering, but they are buried under much stronger background elastic features. Here, we exploit the rich dynamical information encoded in the inelastic patterns, which we reveal by frequency-dispersed covariance ultrafast powder X-ray diffraction of stochastic X-ray free-electron laser pulses. This is demonstrated for the photoisomerization of azobenzene involving the passage through a conical intersection, where the nuclear wave packet branches and explores different quantum pathways. Snapshots of the coherence dynamics are obtained at high frequency shifts, not accessible with conventional diffraction measurements. These provide access to the timing and to the confined spatial distribution of the valence electrons directly involved in the conical intersection passage. This study can be extended to full three-dimensional imaging of conical intersections with ultrafast X-ray and electron diffraction.


2001 ◽  
Vol 19 (1) ◽  
pp. 125-131 ◽  
Author(s):  
KENICHI KINOSHITA ◽  
HIDEKI HARANO ◽  
KOJI YOSHII ◽  
TAKERU OHKUBO ◽  
ATSUSHI FUKASAWA ◽  
...  

For ultrafast material analyses, we constructed the time-resolved X-ray diffraction system utilizing ultrashort X-rays from laser-produced plasma generated by the 12-TW–50-fs laser at the Nuclear Engineering Research Laboratory. Ultrafast transient changes in laser-irradiated GaAs crystals were observed as X-ray diffraction patterns. Experimental results were compared with numerical analyses.


Author(s):  
Michele Buzzi ◽  
Michael Först ◽  
Andrea Cavalleri

Strong interactions between electrons give rise to the complexity of quantum materials, which exhibit exotic functional properties and extreme susceptibility to external perturbations. A growing research trend involves the study of these materials away from equilibrium, especially in cases in which the stimulation with optical pulses can coherently enhance cooperative orders. Time-resolved X-ray probes are integral to this type of research, as they can be used to track atomic and electronic structures as they evolve on ultrafast timescales. Here, we review a series of recent experiments where femtosecond X-ray diffraction was used to measure dynamics of complex solids. This article is part of the theme issue ‘Measurement of ultrafast electronic and structural dynamics with X-rays’.


2007 ◽  
Vol 25 (2) ◽  
pp. 267-275 ◽  
Author(s):  
A.YA. Faenov ◽  
A.I. Magunov ◽  
T.A. Pikuz ◽  
I. YU. Skobelev ◽  
S.V. Gasilov ◽  
...  

X-ray spectra of plasma produced by the interaction of Ti:Sa laser pulses (duration from 60 fs to 1 ps, and energy from 15 mJ to 128 mJ) with foil and solid Teflon and AL targets are investigated. It is shown experimentally and theoretically that the use of low contrast (10−2 – 10−4) short laser pulses, essentially promotes the conditions for generation of fast multi-charged ions. This effect is caused by self-focusing of the main laser pulse in a preplasma produced by intense laser prepulses. Modeling of the observed spectral line shape gives evidence of a considerable (about 3%) amount of multi-charged He-like F ions with energy E ∼ 1 MeV at rather low values of laser intensity IL ≈ 6 × 1016 W cm−2.


2018 ◽  
Vol 25 (4) ◽  
pp. 1229-1237
Author(s):  
Yuki Takayama ◽  
Yuki Takami ◽  
Keizo Fukuda ◽  
Takamasa Miyagawa ◽  
Yasushi Kagoshima

Coherent X-ray diffraction imaging (CXDI) is a promising technique for non-destructive structural analysis of micrometre-sized non-crystalline samples at nanometre resolutions. This article describes an atmospheric CXDI system developed at SPring-8 Hyogo beamline BL24XU for in situ structural analysis and designed for experiments at a photon energy of 8 keV. This relatively high X-ray energy enables experiments to be conducted under ambient atmospheric conditions, which is advantageous for the visualization of samples in native states. The illumination condition with pinhole-slit optics is optimized according to wave propagation calculations based on the Fresnel–Kirchhoff diffraction formula so that the sample is irradiated by X-rays with a plane wavefront and high photon flux of ∼1 × 1010 photons/16 µmø(FWHM)/s. This work demonstrates the imaging performance of the atmospheric CXDI system by visualizing internal voids of sub-micrometre-sized colloidal gold particles at a resolution of 29.1 nm. A CXDI experiment with a single macroporous silica particle under controlled humidity was also performed by installing a home-made humidity control device in the system. The in situ observation of changes in diffraction patterns according to humidity variation and reconstruction of projected electron-density maps at 5.2% RH (relative humidity) and 82.6% RH at resolutions of 133 and 217 nm, respectively, were accomplished.


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