[Show abstract][Hide abstract] ABSTRACT: We present an experimental study and performance improvement of periodic and aperiodic Ni/SiC multilayer coatings. Periodic Ni/SiC multilayer mirrors have been coated and characterized by grazing incidence X-ray reflectometry at 8.048 keV (Cu K alpha radiation) and by measurements at 3 keV and 5 keV on synchrotron radiation facilities. An interdiffusion effect is found between Ni and SiC layers. A two-material model, NixSiy/SiC, using a silicide instead of Ni, was used to fit the measurements. The addition of 0.6 nm W barrier layers at the interfaces allows a significant reduction of the interdiffusion between Ni and SiC. In order to obtain a specific reflectivity profile in the 2 - 8 keV energy range, we have designed and coated aperiodic multilayer mirrors by using Ni/SiC with and without W barrier layers. The experimental reflectivity profiles as a function of the photon energy were measured on a synchrotron radiation facility in both cases. Adding W barrier layers in Ni/SiC multilayers provides a better precision on the layer thicknesses and a very good agreement between the experimental data and the targeted spectral profile. (C) 2014 Optical Society of America
[Show abstract][Hide abstract] ABSTRACT: Hard X-ray micro-tomography is a powerful tool to reveal the internal structure of thick objects in a non-destructive manner. For synchrotron applications and practical lab works with students, a 2D detector based on a thin YAG:Ce scintillator optically coupled to a new generation high frame rate (100 fps) low noise sCMOS camera has been developed and characterized in depth on the METROLOGIE and PSICH'E beamlines of the SOLEIL synchrotron. The Detector gain, Modulation Transfer Function, Noise Power Spectrum and Detective Quantum Efficiency have been measured and compared with analytical model. A tomography reconstruction was performed on small insects to demonstrate the performance of this X-ray imaging detector.
15TH INTERNATIONAL WORKSHOP ON RADIATION IMAGING DETECTORS (IWORID2013); 06/2014
[Show abstract][Hide abstract] ABSTRACT: High-efficiency nanofocusing of hard X-rays using stacked multilevel Fresnel zone plates with a smallest zone width of 200 nm is demonstrated. The approach is to approximate the ideal parabolic lens profile with two-, three-, four- and six-level zone plates. By stacking binary and three-level zone plates with an additional binary zone plate, the number of levels in the optical transmission function was doubled, resulting in four- and six-level profiles, respectively. Efficiencies up to 53.7% focusing were experimentally obtained with 6.5 keV photons using a compact alignment apparatus based on piezoelectric actuators. The measurements have also been compared with numerical simulations to study the misalignment of the two zone plates.
[Show abstract][Hide abstract] ABSTRACT: We present a method to characterize subnanometric layers based on grazing incidence X-ray reflectometry. For this purpose, we propose to use a “Fabry-Pérot type” multilayer structure in order to improve the sensitivity of the measurement to the layer thickness. For our study, this structure consists of a thin layer of scandium inserted between two periodic chromium (Cr)/scandium (Sc) multilayers. We describe the principle and estimate the sensitivity of the method by simulation. Experiments were performed on two optimized Fabry-Pérot structures with 0.6 and 1.2 nm Sc layer thicknesses using a laboratory grazing incidence reflectometer at 8.048 keV (Cu Kα radiation). Fitting of experimental data allows determining the Sc layer thickness. Finally, the structural parameters used in the fit were confirmed by measurements at 3 keV on the hard X-ray branch of the synchrotron SOLEIL Metrology and Tests beamline.
Thin Solid Films 04/2014; 556. DOI:10.1016/j.tsf.2014.01.001 · 1.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A fast multimodal scanning X-ray imaging scheme is prototyped at Soleil Synchrotron. It permits the simultaneous acquisition of complementary information on the sample structure, composition and chemistry by measuring transmission, differential phase contrast, small-angle scattering, and X-ray fluorescence by dedicated detectors with ms dwell time per pixel. The results of the proof of principle experiments are presented in this paper.
Journal of Physics Conference Series 10/2013; 463(1). DOI:10.1088/1742-6596/463/1/012031
[Show abstract][Hide abstract] ABSTRACT: In recent years, there has been growing interest in the design of electron accelerators in order to reduce beam emittance and to increase photon brilliance (from third-generation synchrotron sources to free electron lasers). This has increased the coherent properties of the beam and has opened up new branches of microscopy and spectroscopy at nanometer-length scales. The X-ray nano probe is going to be an important tool for future research, hence there has been substantial research carried out in order to develop nano focusing optics of diffraction-limited performance.
[Show abstract][Hide abstract] ABSTRACT: Scanning hard X-ray nanoprobe imaging provides a unique tool for probing
specimens with high sensitivity and large penetration depth. Moreover,
the combination of complementary techniques such as X-ray fluorescence,
absorption, phase contrast and dark field imaging gives complete
quantitative information on the sample structure, composition and
chemistry. The multi-technique "FLYSCAN" data acquisition scheme
developed at Synchrotron SOLEIL permits to perform fast continuous
scanning imaging and as such makes scanning tomography techniques
feasible in a time-frame well-adapted to typical user experiments. Here
we present the recent results of simultaneous fast scanning
multi-technique tomography performed at Soleil. This fast scanning
scheme will be implemented at the Nanoscopium beamline for large field
of view 2D and 3D multimodal imaging.
Proceedings of SPIE - The International Society for Optical Engineering 09/2013; 8851. DOI:10.1117/12.2026680 · 0.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The focusing efficiency of binary Fresnel zone plate lenses is
fundamentally limited and higher efficiency requires a multi step lens
profile. To overcome the manufacturing problems of high resolution and
high efficiency multistep zone plates, we investigate the concept of
stacking two different binary zone plates in each other's optical
near-field. We use a coarse zone plate with π phase shift and a
double density fine zone plate with π/2 phase shift to produce an
effective 4- step profile. Using a compact experimental setup with piezo
actuators for alignment, we demonstrated 47.1% focusing efficiency at
6.5 keV using a pair of 500 μm diameter and 200 nm smallest zone
width. Furthermore, we present a spatially resolved characterization
method using multiple diffraction orders to identify manufacturing
errors, alignment errors and pattern distortions and their effect on
Proceedings of SPIE - The International Society for Optical Engineering 09/2013; 8851. DOI:10.1117/12.2022640 · 0.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this paper we present some quantitative measurements of X-ray phase contrast images and noise evaluation obtained with a recent grating based X-ray phase contrast interferometer. This device is built using a single phase grating and a large broadband X-ray source. It was calibrated using a reference sample and finally used to perform measurements of a biological fossil: a mosquito trapped in amber. As phase images, noise was evaluated from the measured interferograms. (C) 2013 Optical Society of America
[Show abstract][Hide abstract] ABSTRACT: As already proven by the astronomy community, adaptive optics can be used to correct wavefront aberration. This paper presents various concepts and few results on adaptive/active X-ray mirror designs for synchrotrons and FELs applications.
Adaptive Optics: Methods, Analysis and Applications; 06/2013
[Show abstract][Hide abstract] ABSTRACT: We present a comparative study of B4C/Mo and B4C/Mo2C periodic multilayer structures deposited by magnetron sputtering. The characterization was performed by grazing incidence X-ray reflectometry at two different energies and high resolution transmission electron microscopy. The experimental results indicate the existence of an interdiffusion layer at the B4C-on-Mo interface in the B4C/Mo system. Thus, the B4C/Mo multilayers were modeled by an asymmetric structure with three layers in each period. The thickness of B4C-on-Mo interfacial layer was estimated about 1.1 nm. The B4C/Mo2C multilayers present less interdiffusion and are well modeled by a symmetric structure without interfacial layers. This study shows that B4C/Mo2C structure is an interesting alternative to B4C/Mo multilayer for X-ray optic applications.
Applied Physics A 04/2013; 111(1). DOI:10.1007/s00339-013-7560-3 · 1.70 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this paper, we will present coherent diffraction imaging reconstruction of a well-known object by use of a Hybrid Input-Output algorithm. The sample was imaged at 400 nm wavelength with a fully coherent laser source and at 0.41 nm wavelength in partially coherent illumination. The comparison of the two experiments, completed with theoretical simulations, will highlight the influence of the degree of spatial coherence in the reconstruction process.
Journal of Physics Conference Series 03/2013; 425(19):192009. DOI:10.1088/1742-6596/425/19/192009
[Show abstract][Hide abstract] ABSTRACT: Recently, Onera developed a new interferometer for X-ray phase contrast imaging. This device uses a single phase grating and takes advantage of the incident light spectral bandwidth to create an achromatic and propagation-invariant pattern. This very simple setup produces highly contrasted interferograms after a certain distance of propagation. Our first quantitative images are presented in this paper and the performances of the device are discussed.
Journal of Physics Conference Series 03/2013; 425(19):192002. DOI:10.1088/1742-6596/425/19/192002
[Show abstract][Hide abstract] ABSTRACT: This paper presents a study of B4C/Mo2C multilayers mirrors with the aim of using it in the achievement of Alternate MultiLayer (AML) grating. Such component allows a high efficiency in the 500-2500 eV energy range for the DEIMOS beamline. Multilayers were deposited on silicon substrate. They are characterized by reflectometry under grazing incidence. Numerical adjustments were performed with a model of two layers in the period without any interfacial. A prototype of AML grating was fabricated and characterized. The efficiency of the first order of diffraction was worth 15% at 1700 eV.
Journal of Physics Conference Series 03/2013; 425(15):152007. DOI:10.1088/1742-6596/425/15/152007
[Show abstract][Hide abstract] ABSTRACT: A distributed fast-acquisition system for synchronized multi-technique experiments is presented, in which the collection of metadata and the asynchronous merging of large data volumes from multiple detectors are managed as part of the data collection process. This fast continuous scanning scheme, named FLYSCAN, enables measurement of microscopy data on a timescale of milliseconds per pixel. Proof-of-principle multi-technique experiments, namely scanning X-ray fluorescence spectrometry combined with absorption, differential phase contrast and dark-field imaging, have been performed on biological and geological samples.
[Show abstract][Hide abstract] ABSTRACT: Multi-lateral shearing interferometry  is an evolution of the
classical lateral shearing interferometry: a grating based technique
used for optical testing. Firstly developed for adaptive optics, for
ultra-intense lasers characterization, or for lens testing, in visible
or infrared, it has now been applied to visible quantitative phase
microscopy of biological samples. The purpose of this paper is to
present the transfer of this technique to the X-ray domain, stressing on
the basic property of propagation invariance.
[Show abstract][Hide abstract] ABSTRACT: The XPAD3, a photon counting hybrid pixel detector developed in collaboration by SOLEIL Synchrotron, the Institut Néel and the Centre de Physique des Particules de Marseille (CPPM) , is now successfully used for a large variety of X-ray experiments on third generation synchrotron light sources . Several 7.3 cm x 12.5 cm imagers composed of 8 silicon modules (7 chips per module, 9600 pixel of 130μm side per chip) are routinely used on different synchrotron beamlines at Soleil and on the CRG beamline D2AM at ESRF. Detector performances such as noiseless detection, high dynamic (27 bits) and fast framing rate (640 fps) have opened up the possibility of new or improved types of measurements. Nevertheless, above 15 keV, besides the loss of efficiency , the X-ray scattering in silicon sensor and the material located behind significantly increases the shape and the width of thepoint-spread function at 0.01% of the maximum. This effect prevents the study of low intensity phenomena such as diffuse scattering, which would be observed at the foot of theBragg peak and theoretically measurable with the large dynamic of the detector. This effect has been measured at different energies with monochromatic synchrotron beam (on CRISTAL and METROLOGIE Soleil beamlines) on a mono module Silicon XPAD and then compared with a Quad CdTe XPAD prototype (cf. figure 1). The results, which will be presented, demonstrate the superiority of the high Z sensor and push the investigation of the CdTe as a material sensor even at mid energy.
[Show abstract][Hide abstract] ABSTRACT: The XPAD3S-CdTe, a CdTe photon-counting pixel array detector, has been used to measure the energy and the intensity of the white-beam diffraction from a lysozyme crystal. A method was developed to calibrate the detector in terms of energy, allowing incident photon energy measurement to high resolution (approximately 140 eV), opening up new possibilities in energy-resolved X-ray diffraction. In order to demonstrate this, Laue diffraction experiments were performed on the bending-magnet beamline METROLOGIE at Synchrotron SOLEIL. The X-ray energy spectra of diffracted spots were deduced from the indexed Laue patterns collected with an imaging-plate detector and then measured with both the XPAD3S-CdTe and the XPAD3S-Si, a silicon photon-counting pixel array detector. The predicted and measured energy of selected diffraction spots are in good agreement, demonstrating the reliability of the calibration method. These results open up the way to direct unit-cell parameter determination and the measurement of high-quality Laue data even at low resolution. Based on the success of these measurements, potential applications in X-ray diffraction opened up by this type of technology are discussed.