Showing papers in "Journal of Synchrotron Radiation in 2012"

Facilities for macromolecular crystallography at the Helmholtz-Zentrum Berlin

Abstract: Three macromolecular crystallography (MX) beamlines at the Helmholtz-Zentrum Berlin (HZB) are available for the regional, national and international structural biology user community. The state-of-the-art synchrotron beamlines for MX BL14.1, BL14.2 and BL14.3 are located within the low-β section of the BESSY II electron storage ring. All beamlines are fed from a superconducting 7 T wavelength-shifter insertion device. BL14.1 and BL14.2 are energy tunable in the range 5–16 keV, while BL14.3 is a fixed-energy side station operated at 13.8 keV. All three beamlines are equipped with CCD detectors. BL14.1 and BL14.2 are in regular user operation providing about 200 beam days per year and about 600 user shifts to approximately 50 research groups across Europe. BL14.3 has initially been used as a test facility and was brought into regular user mode operation during the year 2010. BL14.1 has recently been upgraded with a microdiffractometer including a mini-κ goniometer and an automated sample changer. Additional user facilities include office space adjacent to the beamlines, a sample preparation laboratory, a biology laboratory (safety level 1) and high-end computing resources. In this article the instrumentation of the beamlines is described, and a summary of the experimental possibilities of the beamlines and the provided ancillary equipment for the user community is given.

Regridding reconstruction algorithm for real-time tomographic imaging

Abstract: Sub-second temporal-resolution tomographic microscopy is becoming a reality at third-generation synchrotron sources. Efficient data handling and post-processing is, however, difficult when the data rates are close to 10 GB s−1. This bottleneck still hinders exploitation of the full potential inherent in the ultrafast acquisition speed. In this paper the fast reconstruction algorithm gridrec, highly optimized for conventional CPU technology, is presented. It is shown that gridrec is a valuable alternative to standard filtered back-projection routines, despite being based on the Fourier transform method. In fact, the regridding procedure used for resampling the Fourier space from polar to Cartesian coordinates couples excellent performance with negligible accuracy degradation. The stronger dependence of the observed signal-to-noise ratio for gridrec reconstructions on the number of angular views makes the presented algorithm even superior to filtered back-projection when the tomographic problem is well sampled. Gridrec not only guarantees high-quality results but it provides up to 20-fold performance increase, making real-time monitoring of the sub-second acquisition process a reality.

DESIRS: a state‐of‐the‐art VUV beamline featuring high resolution and variable polarization for spectroscopy and dichroism at SOLEIL

Abstract: DESIRS is a new undulator-based VUV beamline on the 2.75 GeV storage ring SOLEIL (France) optimized for gas-phase studies of molecular and electronic structures, reactivity and polarization-dependent photodynamics on model or actual systems encountered in the universe, atmosphere and biosphere. It is equipped with two dedicated endstations: a VUV Fourier-transform spectrometer (FTS) for ultra-high-resolution absorption spectroscopy (resolving power up to 106) and an electron/ion imaging coincidence spectrometer. The photon characteristics necessary to fulfill its scientific mission are: high flux in the 5–40 eV range, high spectral purity, high resolution, and variable and well calibrated polarizations. The photon source is a 10 m-long pure electromagnetic variable-polarization undulator producing light from the very near UV up to 40 eV on the fundamental emission with tailored elliptical polarization allowing fully calibrated quasi-perfect horizontal, vertical and circular polarizations, as measured with an in situ VUV polarimeter with absolute polarization rates close to unity, to be obtained at the sample location. The optical design includes a beam waist allowing the implementation of a gas filter to suppress the undulator high harmonics. This harmonic-free radiation can be steered toward the FTS for absorption experiments, or go through a highly efficient pre-focusing optical system, based on a toroidal mirror and a reflective corrector plate similar to a Schmidt plate. The synchrotron radiation then enters a 6.65 m Eagle off-plane normal-incidence monochromator equipped with four gratings with different groove densities, from 200 to 4300 lines mm−1, allowing the flux-to-resolution trade-off to be smoothly adjusted. The measured ultimate instrumental resolving powers are 124000 (174 µeV) around 21 eV and 250000 (54 µeV) around 13 eV, while the typical measured flux is in the 1010–1011 photons s−1 range in a 1/50000 bandwidth, and 1012–1013 photons s−1 in a 1/1000 bandwidth, which is very satisfactory although slightly below optical simulations. All of these features make DESIRS a state-of-the-art VUV beamline for spectroscopy and dichroism open to a broad scientific community.

P03, the microfocus and nanofocus X-ray scattering (MiNaXS) beamline of the PETRA III storage ring: the microfocus endstation

Abstract: The P03 beamline, also called the microfocus and nanofocus X-ray scattering (MiNaXS) beamline, exploits the excellent photon beam properties of the low-emittance source PETRA III to provide a microfocused/nanofocused beam with ultra-high intensity for time-resolved X-ray scattering experiments. The beamline has been designed to perform X-ray scattering in both transmission and reflection geometries. The microfocus endstation started user operation in May 2011. An overview of the beamline status and of some representative results highlighting the performance of the microfocus endstation at MiNaXS are given.

TXM-Wizard: a program for advanced data collection and evaluation in full-field transmission X-ray microscopy

Abstract: Transmission X-ray microscopy (TXM) has been well recognized as a powerful tool for non-destructive investigation of the three-dimensional inner structure of a sample with spatial resolution down to a few tens of nanometers, especially when combined with synchrotron radiation sources. Recent developments of this technique have presented a need for new tools for both system control and data analysis. Here a software package developed in MATLAB for script command generation and analysis of TXM data is presented. The first toolkit, the script generator, allows automating complex experimental tasks which involve up to several thousand motor movements. The second package was designed to accomplish computationally intense tasks such as data processing of mosaic and mosaic tomography datasets; dual-energy contrast imaging, where data are recorded above and below a specific X-ray absorption edge; and TXM X-ray absorption near-edge structure imaging datasets. Furthermore, analytical and iterative tomography reconstruction algorithms were implemented. The compiled software package is freely available.

PITRE: software for phase-sensitive X-ray image processing and tomography reconstruction.

Abstract: Synchrotron-radiation computed tomography has been applied in many research fields. Here, PITRE (Phase-sensitive X-ray Image processing and Tomography REconstruction) and PITRE_BM (PITRE Batch Manager) are presented. PITRE supports phase retrieval for propagation-based phase-contrast imaging/tomography (PPCI/PPCT), extracts apparent absorption, refractive and scattering information of diffraction enhanced imaging (DEI), and allows parallel-beam tomography reconstruction for conventional absorption CT data and for PPCT phase retrieved and DEI-CT extracted information. PITRE_BM is a batch processing manager for PITRE: it executes a series of tasks, created via PITRE, without manual intervention. Both PITRE and PITRE_BM are coded in Interactive Data Language (IDL), and have a user-friendly graphical user interface. They are freeware and can run on Microsoft Windows systems via IDL Virtual Machine, which can be downloaded for free and does not require a license. The data-processing principle and some examples of application will be presented.

ID29: a high-intensity highly automated ESRF beamline for macromolecular crystallography experiments exploiting anomalous scattering.

Abstract: ID29 is an ESRF undulator beamline with a routinely accessible energy range of between 20.0 keV and 6.0 keV (λ = 0.62 A to 2.07 A) dedicated to the use of anomalous dispersion techniques in macromolecular crystallography. Since the beamline was first commissioned in 2001, ID29 has, in order to provide an improved service to both its academic and proprietary users, been the subject of almost continuous upgrade and refurbishment. It is now also the home to the ESRF Cryobench facility, ID29S. Here, the current status of the beamline is described and plans for its future are briefly outlined.

A hard X-ray nanoprobe beamline for nanoscale microscopy

Abstract: The Hard X-ray Nanoprobe Beamline (or Nanoprobe Beamline) is an X-ray microscopy facility incorporating diffraction, fluorescence and full-field imaging capabilities designed and operated by the Center for Nanoscale Materials and the Advanced Photon Source at Sector 26 of the Advanced Photon Source at Argonne National Laboratory. This facility was constructed to probe the nanoscale structure of biological, environmental and material sciences samples. The beamline provides intense focused X-rays to the Hard X-ray Nanoprobe (or Nanoprobe) which incorporates Fresnel zone plate optics and a precision laser sensing and control system. The beamline operates over X-ray energies from 3 to 30 keV, enabling studies of most elements in the periodic table, with a particular emphasis on imaging transition metals.

The 57Fe Synchrotron Mössbauer Source at the ESRF.

Abstract: The design of a 57Fe Synchrotron Mossbauer Source (SMS) for energy-domain Mossbauer spectroscopy using synchrotron radiation at the Nuclear Resonance beamline (ID18) at the European Synchrotron Radiation Facility is described. The SMS is based on a nuclear resonant monochromator employing pure nuclear reflections of an iron borate (57FeBO3) crystal. The source provides 57Fe resonant radiation at 14.4 keV within a bandwidth of 15 neV which is tunable in energy over a range of about ±0.6 µeV. In contrast to radioactive sources, the beam of γ-radiation emitted by the SMS is almost fully resonant and fully polarized, has high brilliance and can be focused to a 10 µm × 5 µm spot size. Applications include, among others, the study of very small samples under extreme conditions, for example at ultrahigh pressure or combined high pressure and high temperature, and thin films under ultrahigh vacuum. The small cross section of the beam and its high intensity allow for rapid collection of Mossbauer data. For example, the measuring time of a spectrum for a sample in a diamond anvil cell at ∼100 GPa is around 10 min, whereas such an experiment with a radioactive point source would take more than one week and the data quality would be considerably less. The SMS is optimized for highest intensity and best energy resolution, which is achieved by collimation of the incident synchrotron radiation beam and thus illumination of the high-quality iron borate crystal within a narrow angular range around an optimal position of the rocking curve. The SMS is permanently located in an optics hutch and is operational immediately after moving it into the incident beam. The SMS is an in-line monochromator, i.e. the beam emitted by the SMS is directed almost exactly along the incident synchrotron radiation beam. Thus, the SMS can be easily utilized with all existing sample environments in the experimental hutches of the beamline. Owing to a very strong suppression of electronic scattering for pure nuclear reflections (∼10−9), SMS operation does not required any gating of the prompt electronic scattering. Thus, the SMS can be utilized in any mode of storage ring operation.

X-Treme beamline at SLS: X-ray magnetic circular and linear dichroism at high field and low temperature

Abstract: X-Treme is a soft X-ray beamline recently built in the Swiss Light Source at the Paul Scherrer Institut in collaboration with Ecole Polytechnique Federale de Lausanne. The beamline is dedicated to polarization-dependent X-ray absorption spectroscopy at high magnetic fields and low temperature. The source is an elliptically polarizing undulator. The end-station has a superconducting 7 T–2 T vector magnet, with sample temperature down to 2 K and is equipped with an in situ sample preparation system for surface science. The beamline commissioning measurements, which show a resolving power of 8000 and a maximum flux at the sample of 4.7 × 1012 photons s−1, are presented. Scientific examples showing X-ray magnetic circular and X-ray magnetic linear dichroism measurements are also presented.

X-ray-induced photo-chemistry and X-ray absorption spectroscopy of biological samples.

Abstract: As synchrotron light sources and optics deliver greater photon flux on samples, X-ray-induced photo-chemistry is increasingly encountered in X-ray absorption spectroscopy (XAS) experiments. The resulting problems are particularly pronounced for biological XAS experiments. This is because biological samples are very often quite dilute and therefore require signal averaging to achieve adequate signal-to-noise ratios, with correspondingly greater exposures to the X-ray beam. This paper reviews the origins of photo-reduction and photo-oxidation, the impact that they can have on active site structure, and the methods that can be used to provide relief from X-ray-induced photo-chemical artifacts.

The new ambient‐pressure X‐ray photoelectron spectroscopy instrument at MAX‐lab

Abstract: The new instrument for near-ambient-pressure X-ray photoelectron spectroscopy which has been installed at the MAX II ring of the Swedish synchrotron radiation facility MAX IV Laboratory in Lund is presented. The new instrument, which is based on a SPECS PHOIBOS 150 NAP analyser, is the first to feature the use of retractable and exchangeable high-pressure cells. This implies that clean vacuum conditions are retained in the instrument's analysis chamber and that it is possible to swiftly change between near-ambient and ultrahigh-vacuum conditions. In this way the instrument implements a direct link between ultrahigh-vacuum and in situ studies, and the entire pressure range from ultrahigh-vacuum to near-ambient conditions is available to the user. Measurements at pressures up to 10−5 mbar are carried out in the ultrahigh-vacuum analysis chamber, while measurements at higher pressures are performed in the high-pressure cell. The installation of a mass spectrometer on the exhaust line of the reaction cell offers the users the additional dimension of simultaneous reaction data monitoring. Moreover, the chosen design approach allows the use of dedicated cells for different sample environments, rendering the Swedish ambient-pressure X-ray photoelectron spectroscopy instrument a highly versatile and flexible tool.

The dedicated high-resolution grazing-incidence X-ray scattering beamline 8-ID-E at the Advanced Photon Source

Abstract: As an increasingly important structural-characterization technique, grazing-incidence X-ray scattering (GIXS) has found wide applications for in situ and real-time studies of nanostructures and nanocomposites at surfaces and interfaces. A dedicated beamline has been designed, constructed and optimized at beamline 8-ID-E at the Advanced Photon Source for high-resolution and coherent GIXS experiments. The effectiveness and applicability of the beamline and the scattering techniques have been demonstrated by a host of experiments including reflectivity, grazing-incidence static and kinetic scattering, and coherent surface X-ray photon correlation spectroscopy. The applicable systems that can be studied at 8-ID-E include liquid surfaces and nanostructured thin films.

The high-resolution diffraction beamline P08 at PETRA III

Abstract: The new third-generation synchrotron radiation source PETRA III located at the Deutsches Elektronen-Synchrotron DESY in Hamburg, Germany, has been operational since the second half of 2009. PETRA III is designed to deliver hard X-ray beams with very high brilliance. As one of the first beamlines of PETRA III the high-resolution diffraction beamline P08 is fully operational. P08 is specialized in X-ray scattering and diffraction experiments on solids and liquids where extreme high resolution in reciprocal space is required. The resolving power results in the high-quality PETRA III beam and unique optical elements such as a large-offset monochromator and beryllium lens changers. A high-precision six-circle diffractometer for solid samples and a specially designed liquid diffractometer are installed in the experimental hutch. Regular users have been accepted since summer 2010.

I19, the small-molecule single-crystal diffraction beamline at Diamond Light Source

Abstract: The dedicated small-molecule single-crystal X-ray diffraction beamline (I19) at Diamond Light Source has been operational and supporting users for over three years. I19 is a high-flux tunable-wavelength beamline and its key details are described in this article. Much of the work performed on the beamline involves structure determination from small and weakly diffracting crystals. Other experiments that have been supported to date include structural studies at high pressure, studies of metastable species, variable-temperature crystallography, studies involving gas exchange in porous materials and structural characterizations that require analysis of the diffuse scattering between Bragg reflections. A range of sample environments to facilitate crystallographic studies under non-ambient conditions are available as well as a number of options for automation. An indication of the scope of the science carried out on the beamline is provided by the range of highlights selected for this paper.

Status of the hard X-ray microprobe beamline ID22 of the European Synchrotron Radiation Facility.

Abstract: The ESRF synchrotron beamline ID22, dedicated to hard X-ray microanalysis and consisting of the combination of X-ray fluorescence, X-ray absorption spectroscopy, diffraction and 2D/3D X-ray imaging techniques, is one of the most versatile instruments in hard X-ray microscopy science. This paper describes the present beamline characteristics, recent technical developments, as well as a few scientific examples from recent years of the beamline operation. The upgrade plans to adapt the beamline to the growing needs of the user community are briefly discussed.

Performance and status of beamline BL8 at SLRI for X-ray absorption spectroscopy.

Abstract: Beamline BL8 of the Synchrotron Light Research Institute (Thailand) is routinely operated for X-ray absorption spectroscopy (XAS) in an intermediate photon energy range (1.25–10 keV). The photon energy is scanned by using a double-crystal monochromator, the crystal pair of which can be interchanged among KTP(011), InSb(111), Si(111) and Ge(220). The experimental set-up conveniently facilitates XAS measurements in transmission and fluorescence-yield modes at several K-edges of elements ranging from magnesium to zinc. Instrumentation and specification of the beamline and the XAS station are described, together with the determination of the available photon flux [0.1–6 × 1010 photon s−1 (100 mA)−1], energy resolution (1–5 × 10−4) and stability of photon energy calibration (0.07 eV), representing the beamline performance. Data quality and accuracy of XANES and EXAFS measured at BL8 are compared with those of other well established beamlines. A noted distinction of BL8 is its relatively high sensitivity for studying phosphorous, sulfur and chlorine in diluted systems and its maximum beam size of 14 mm (width) × 1 mm (height), which is suitable for bulk characterization.

Performance upgrade in the JAEA actinide science beamline BL23SU at SPring-8 with a new twin-helical undulator

Abstract: The soft X-ray beamline BL23SU at SPring-8 has undergone an upgrade with a twin-helical undulator of in-vacuum type to enhance the experimental capabilities of the endstations. The new light source with a fast helicity-switching operation allows not only the data throughput but also the sensitivity in X-ray magnetic circular dichroism (XMCD) to be improved. The operational performance and potential are described by presenting XMCD results of paramagnetic β-US2 measured with a 10 T superconducting magnet.

Circular dichroism beamline B23 at the Diamond Light Source.

Abstract: Synchrotron radiation circular dichroism (SRCD) is a well established technique in structural biology. The first UV-VIS beamline, dedicated to circular dichroism, at Diamond Light Source Ltd, a third-generation synchrotron facility in south Oxfordshire, UK, has recently become operational and it is now available for the user community. Herein the main characteristics of the B23 SRCD beamline, the ancillary facilities available for users, and some of the recent advances achieved are summarized.

The 7BM beamline at the APS: a facility for time-resolved fluid dynamics measurements

Abstract: In recent years, X-ray radiography has been used to probe the internal structure of dense sprays with microsecond time resolution and a spatial resolution of 15 µm even in high-pressure environments. Recently, the 7BM beamline at the Advanced Photon Source (APS) has been commissioned to focus on the needs of X-ray spray radiography measurements. The spatial resolution and X-ray intensity at this beamline represent a significant improvement over previous time-resolved X-ray radiography measurements at the APS.

Glitch-free X-ray absorption spectrum under high pressure obtained using nano-polycrystalline diamond anvils

Abstract: Nano-polycrystalline diamond (NPD) [Irifune et al. (2003), Nature (London), 421, 599] has been used to obtain a glitch-free X-ray absorption spectrum under high pressure. In the case of conventional single-crystal diamond (SCD) anvils, glitches owing to Bragg diffraction from the anvils are superimposed on X-ray absorption spectra. The glitch has long been a serious problem for high-pressure research activities using X-ray spectroscopy because of the difficulties of its complete removal. It is demonstrated that NPD is one of the best candidate materials to overcome this problem. Here a glitch-free absorption spectrum using the NPD anvils over a wide energy range is shown. The advantage and capability of NPD anvils is discussed by a comparison of the glitch map with that of SCD anvils.

A 30 nm-resolution hard X-ray microscope with X-ray fluorescence mapping capability at BSRF

Abstract: A full-field transmission X-ray microscope (TXM) operating continuously from 5 keV to 12 keV with fluorescence mapping capability has been designed and constructed at the Beijing Synchrotron Radiation Facility, a first-generation synchrotron radiation facility operating at 2.5 GeV. Spatial resolution better than 30 nm has been demonstrated using a Siemens star pattern in both absorption mode and Zernike phase-contrast mode. A scanning-probe mode fluorescence mapping capability integrated with the TXM has been shown to provide 50 p. p. m. sensitivity for trace elements with a spatial resolution (limited by probing beam spot size) of 20 mm. The optics design, testing of spatial resolution and fluorescence sensitivity are presented here, including performance measurement results.

Development of a laser-based heating system for in situ synchrotron-based X-ray tomographic microscopy

Abstract: Understanding the formation of materials at elevated temperatures is critical for determining their final properties. Synchrotron-based X-ray tomographic microscopy is an ideal technique for studying such processes because high spatial and temporal resolutions are easily achieved and the technique is non-destructive, meaning additional analyses can take place after data collection. To exploit the state-of-the-art capabilities at the tomographic microscopy and coherent radiology experiments (TOMCAT) beamline of the Swiss Light Source, a general-use moderate-to-high-temperature furnace has been developed. Powered by two diode lasers, it provides controlled localized heating, from 673 to 1973 K, to examine many materials systems and their dynamics in real time. The system can also be operated in various thermal modalities. For example, near-isothermal conditions at a given sample location can be achieved with a prescribed time-dependent temperature. This mode is typically used to study isothermal phase transformations; for example, the formation of equiaxed grains in metallic systems or to nucleate and grow bubble foams in silicate melts under conditions that simulate volcanic processes. In another mode, the power of the laser can be fixed and the specimen moved at a constant speed in a user-defined thermal gradient. This is similar to Bridgman solidification, where the thermal gradient and cooling rate control the microstructure formation. This paper details the experimental set-up and provides multiple proofs-of-concept that illustrate the versatility of using this laser-based heating system to explore, in situ, many elevated-temperature phenomena in a variety of materials.

An integrated high-throughput data acquisition system for biological solution X-ray scattering studies

Abstract: A fully automated high-throughput solution X-ray scattering data collection system has been developed for protein structure studies at beamline 4-2 of the Stanford Synchrotron Radiation Lightsource. It is composed of a thin-wall quartz capillary cell, a syringe needle assembly on an XYZ positioning arm for sample delivery, a water-cooled sample rack and a computer-controlled fluid dispenser. It is controlled by a specifically developed software component built into the standard beamline control program Blu-Ice/DCS. The integrated system is intuitive and very simple to use, and enables experimenters to customize data collection strategy in a timely fashion in concert with an automated data processing program. The system also allows spectrophotometric determination of protein concentration for each sample aliquot in the beam via an in situ UV absorption spectrometer. A single set of solution scattering measurements requires a 20–30 µl sample aliquot and takes typically 3.5 min, including an extensive capillary cleaning cycle. Over 98.5% of measurements are valid and free from artefacts commonly caused by air-bubble contamination. The sample changer, which is compact and light, facilitates effortless switching with other sample-handling devices required for other types of non-crystalline X-ray scattering experiments.

Zone-doubled Fresnel zone plates for high-resolution hard X-ray full-field transmission microscopy

Abstract: Full-field transmission X-ray microscopy is a unique non-destructive technique for three-dimensional imaging of specimens at the nanometer scale. Here, the use of zone-doubled Fresnel zone plates to achieve a spatial resolution better than 20 nm in the hard X-ray regime (8–10 keV) is reported. By obtaining a tomographic reconstruction of a Ni/YSZ solid-oxide fuel cell, the feasibility of performing three-dimensional imaging of scientifically relevant samples using such high-spatial-resolution Fresnel zone plates is demonstrated.

The SAMBA quick-EXAFS monochromator: XAS with edge jumping.

Abstract: Results and performances of the QEXAFS double monochromator of the SAMBA beamline (Synchrotron SOLEIL) are presented. The device is capable of speeds of up to 40 Hz, while giving the user the possibility to choose the amplitude of the scan from 0.1° to 4° in a few seconds. The device is composed of two independent units and it is possible to perform scans alternating between two different crystals, literally jumping from low (4 keV) to high (37 keV) energies.

Increase of lifespan for glioma-bearing rats by using minibeam radiation therapy.

Abstract: This feasibility work assesses the therapeutic effectiveness of minibeamradiation therapy, a new synchrotron radiotherapy technique. In this newapproach the irradiation is performed on 9L gliosarcoma-bearing rats witharrays of parallel beams of width 500–700 mm. Two irradiation configurationswere compared: a lateral unidirectional irradiation and two orthogonal arraysinterlacing at the target. A dose escalation study was performed. A factor ofthree gain in the mean survival time obtained for some animals paves the wayfor further exploration of the different possibilities of this technique and itsfurther optimization.

Sub‐10 nm beam confinement by X‐ray waveguides: design, fabrication and characterization of optical properties

Abstract: The propagation of hard X-ray synchrotron beams in waveguides with guiding layer diameters in the 9–35 nm thickness range has been studied. The planar waveguide structures consist of an optimized two-component cladding. The presented fabrication method is suitable for short and leak-proof waveguide slices with lengths (along the optical axis) in the sub-500 µm range, adapted for optimized transmission at photon energies of 11.5–18 keV. A detailed comparison between finite-difference simulations of waveguide optics and the experimental results is presented, concerning transmission, divergence of the waveguide exit beam, as well as the angular acceptance. In a second step, two crossed waveguides have been used to create a quasi-point source for propagation-based X-ray imaging at the new nano-focus endstation of the P10 coherence beamline at Petra III. By inverting the measured Fraunhofer diffraction pattern by an iterative error-reduction algorithm, a two-dimensional focus of 10 nm × 10 nm is obtained. Finally, holographic imaging of a lithographic test structure based on this optical system is demonstrated.

VUV synchrotron radiation: a new activation technique for tandem mass spectrometry.

Abstract: A novel experimental technique for tandem mass spectrometry and ion spectroscopy of electrosprayed ions using vacuum-ultraviolet (VUV) synchrotron radiation is presented. Photon activation of trapped precursor ions has been performed by coupling a commercial linear quadrupole ion trap (Thermo scientific LTQ XL), equipped with the electrosprayed ions source, to the DESIRS beamline at the SOLEIL synchrotron radiation facility. The obtained results include, for the first time on biopolymers, photodetachment spectroscopy using monochromated synchrotron radiation of multi-charged anions and the single photon ionization of large charge-selected polycations. The high efficiency and signal-to-noise ratio achieved by the present set-up open up possibilities of using synchrotron light as a new controllable activation method in tandem mass spectrometry of biopolymers and VUV-photon spectroscopy of large biological ions.

Capturing dynamics with Eiger, a fast-framing X-ray detector

Abstract: Eiger is the next-generation single-photon-counting pixel detector following the widely used Pilatus detector. Its smaller pixel size of 75 µm × 75 µm, higher frame rate of up to 22 kHz, and practically zero dead-time (∼4 µs) between exposures will further various measurement methods at synchrotron sources. In this article Eiger's suitability for X-ray photon correlation spectroscopy (XPCS) is demonstrated. By exploiting its high frame rate, complementary small-angle X-ray scattering (SAXS) and XPCS data are collected in parallel to determine both the structure factor and collective diffusion coefficient of a nano-colloid suspension. For the first time, correlation times on the submillisecond time scale are accessible with a large-area pixel detector.