scholarly journals A simultaneous multiple angle-wavelength dispersive X-ray reflectometer using a bent-twisted polychromator crystal

2012 ◽  
Vol 20 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Tadashi Matsushita ◽  
Etsuo Arakawa ◽  
Wolfgang Voegeli ◽  
Yohko F. Yano
Keyword(s):  
Structural Changes ◽  
Vertical Direction ◽  
Sample Surface ◽  
Array Detector ◽  
Single Crystal Substrate ◽  
Time Resolved ◽  
Reflectivity Curve ◽  
X Ray ◽  
Monochromator Crystal ◽  
Crystal Substrate

An X-ray reflectometer has been developed, which can simultaneously measure the whole specular X-ray reflectivity curve with no need for rotation of the sample, detector or monochromator crystal during the measurement. A bent-twisted crystal polychromator is used to realise a convergent X-ray beam which has continuously varying energyE(wavelength λ) and glancing angle α to the sample surface as a function of horizontal direction. This convergent beam is reflected in the vertical direction by the sample placed horizontally at the focus and then diverges horizontally and vertically. The normalized intensity distribution of the reflected beam measured downstream of the specimen with a two-dimensional pixel array detector (PILATUS 100K) represents the reflectivity curve. Specular X-ray reflectivity curves were measured from a commercially available silicon (100) wafer, a thin gold film coated on a silicon single-crystal substrate and the surface of liquid ethylene glycol with data collection times of 0.01 to 1000 s using synchrotron radiation from a bending-magnet source of a 6.5 GeV electron storage ring. A typical value of the simultaneously covered range of the momentum transfer was 0.01–0.45 Å−1for the silicon wafer sample. The potential of this reflectometer for time-resolved X-ray studies of irreversible structural changes is discussed.

scholarly journals A quick laboratory X-ray reflectometer for time-resolved observations

2014 ◽  
Vol 70 (a1) ◽  
pp. C884-C884
Author(s):  
Chika Kamezawa ◽  
Wolfgang Voegeli ◽  
Wakari Hishinuma ◽  
Etsuo Arakawa ◽  
Tadashi Matsushita ◽  
...  
Keyword(s):  
Momentum Transfer ◽  
Structural Information ◽  
Incident Angle ◽  
Array Detector ◽  
Measured Intensity ◽  
Time Resolved ◽  
Reflectivity Curve ◽  
X Ray ◽  
Laboratory Characteristic ◽  
Long Time

The measurement of the X-ray reflectivity curve is a widely used method to obtain structural information about thin films, surfaces and interfaces. With conventional instruments, the reflectivity curve is measured sequentially for a range of incident angles, which takes a long time. A recently developed method using white synchrotron radiation can measure the whole curve at once [1, 2]. In this contribution, the adaption of this method to a laboratory characteristic X-ray source is presented. This will make it possible to do time-resolved or high-throughput measurements using standard laboratory sources. The basic idea of our method is to focus the divergent X-ray beam emitted from a point source with either a doubly-curved Si crystal monochromator or a bent-twisted Si crystal monochromator [1]. Instead of using the whole beam, however, only the fan-shaped beam from a diagonal line on the monochromator is focused onto the sample. This is realized by placing an inclined slit before the monochoromator. The beam reflected from the sample forms a line on a two-dimensional pixel array detector. For each horizontal position on the detector, the incident angle onto the sample, and therefore the momentum transfer, is different. The reflectivity curve for a range of momentum transfers can therefore be measured with a single detector exposure without moving the sample, monochromator or detector. Reflectivity curves from a silicon wafer sample measured by our method are compared with the conventional angle scan method in the figure. The reflectivity down to 10 to the -7th power can be obtained, because the background can be subtracted from the measured intensity. We will show an example of time-resolved (10 s) measurements of specular X-ray reflectivity curves. We will also discuss the momentum transfer range that can be measured simultaneously and factors limiting the resolution of the method.

Characterization of a prototype pixel array detector (PAD) for use in microsecond framing time-resolved X-ray diffraction studies

1997 ◽  
Vol 44 (3) ◽  
pp. 950-956 ◽  
Author(s):  
S.L. Barna ◽  
J.A. Shepherd ◽  
M.W. Tate ◽  
R.L. Wixted ◽  
E.F. Eikenberry ◽  
...  
Keyword(s):  
Array Detector ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Pixel Array ◽  
Pixel Array Detector

scholarly journals Development of a fast pixel array detector for use in microsecond time-resolved x-ray diffraction

1995 ◽  
Author(s):  
Sandor L. Barna ◽  
John A. Shepherd ◽  
Robert L. Wixted ◽  
Mark W. Tate ◽  
Brian G. Rodricks ◽  
...  
Keyword(s):  
Array Detector ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Pixel Array ◽  
Pixel Array Detector

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

Following the structural changes during zinc-induced crystallization of charged membranes using time-resolved solution X-ray scattering

Soft Matter ◽  
2011 ◽  
Vol 7 (4) ◽  
pp. 1512-1523 ◽  
Author(s):  
Moshe Nadler ◽  
Ariel Steiner ◽  
Tom Dvir ◽  
Or Szekely ◽  
Pablo Szekely ◽  
...  
Keyword(s):  
Structural Changes ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Charged Membranes ◽  
Induced Crystallization ◽  
Ray Scattering

Dynamical Response of the Electric Double Layer Structure of the DEME-TFSI Ionic Liquid to Potential Changes Observed by Time-Resolved X-ray Reflectivity

2016 ◽  
Vol 230 (4) ◽  
Author(s):  
Wolfgang Voegeli ◽  
Etsuo Arakawa ◽  
Tadashi Matsushita ◽  
Osami Sakata ◽  
Yusuke Wakabayashi
Keyword(s):  
Ionic Liquid ◽  
Double Layer ◽  
Time Scale ◽  
Electric Double Layer ◽  
Structural Changes ◽  
Layer Structure ◽  
Dynamical Response ◽  
Relaxation Processes ◽  
Time Resolved ◽  
X Ray

AbstractThe interface between the N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide (DEME-TFSI) ionic liquid and a gold (111) surface was investigated with time-resolved X-ray reflectivity in order to clarify the dynamics of structural changes of the electric double layer after changing the electrode potential. In the experiment, the potential was switched repeatedly between +1.5 V and −1.5 V every 2 s or every 0.3 s, while measuring the specular X-ray reflectivity. When the potential was switched every 2 s, the time dependence of the reflectivity was different from that of the accumulated charge. This indicates structural relaxation processes that occur on a slower time scale than the acummulation of the charge at the electric double layer.When the potential was switched every 0.3 s, on the other hand, the reflectivity changes followed the evolution of the charge of the electric double layer within the experimental precision, indicating that slow relaxation processes without charge transfer do not contribute significantly to structural changes at this time scale.

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