Experimental Endstation Research Articles

X-ray Crystallography at Beamline P11 at PETRA III

The bio-imaging and diffraction beamline P11 at PETRA III is dedicated to structure determination of periodic (crystalline) and aperiodic biological samples. The beamline features two experimental endstations: an X-ray microscope and a crystallography experiment. Basis of design was to provide an extremely stable and flexible setup ideally suited for micro and nano beam applications. The X-ray optics consist of a HHL double crystal monochromator, followed by two horizontal deflecting and one vertical deflecting X-ray mirrors. All mirrors are dynamically bendable and used to generate an intermediate focus at 65.5 m from the source with a size of 37 × 221 µm2FWHM (v × h). All experiments are installed on an 8 m long granite support which provides a very stable setup for micro beam experiments. The crystallography endstation is located at the end of the granite at 72.9 m from the source. The experiment is equipped with a high precision single axis goniostat with a combined sphere of confusion of less than 100 nm. X-ray energies are tunable between 5.5 and 30 keV. A second focusing bendable KB mirror system can be used for further demagnification of the secondary source. In this way the beam size can be freely adjusted between 4 × 9 µm2and 300 × 300 µm2FWHM (v × h) with 1013ph/s at 12 keV. Smaller beam sizes down to 1 × 1 µm2with more than 2 × 1011ph/s in the focus can be realized by slitting down the secondary source at the cost of flux. The crystallography endstation is equipped with a Pilatus 6M-F detector which allows fast data collection with up to 25 Hz. Due to the very small beam divergence of the X-ray beam P11 is ideally suited to measure large unit cell systems, such as viruses or large molecular complexes. In addition, the beamline is capable of high-throughput crystallography and fast crystal screening. Crystals can be mounted in less than 10 s using an automatic sample changer. The large sample dewar provides space for 368 crystals.

Serial femtosecond X-ray diffraction of in vivo crystals in intact yeast cells

Peroxisomes are membrane-enclosed organelles in eukaryotic cells with important roles in lipid metabolism and the scavenging of reactive oxygen species. Peroxisomes are capable of carrying an unusually high load of proteins, which under appropriate nutrient conditions results in the in situ crystallization of peroxisomal proteins in several yeast species and vertebrate hepatocytes [1,2]. In the methylotrophic yeast H.polymorpha, the predominant peroxisomal protein alcohol/methanol oxidase (AO) oligomerizes into octameric assemblies with a molecular mass of 600 kDa that spontaneously form 200-500 nm crystallites within peroxisomes [1]. We exposed H.polymorpha cell suspensions containing peroxisome-confined AO crystallites to femtosecond X-ray pulses at the Coherent X-ray Imaging (CXI) experimental endstation at the Linac Coherent Light Source. Peak detection routines mining the resulting scattering profiles identified >5000 Bragg-sampled diffraction patterns, providing the proof of concept that background scattering from the cells does not deteriorate the signal-to-noise ratio to an extent precluding observation of diffraction from individual AO crystallites. Summation patterns assembled from the individual frames match low-resolution powder diffraction patterns from concentrated suspensions of purified peroxisomes collected at the P14 beamline at the PETRAIII synchrotron, confirming that the observed diffraction mainly results from Bragg scattering of peroxisomal crystallites. To the best of our knowledge our data are the first to report room temperature X-ray diffraction from functional protein crystals in their native cellular environment. Currently the maximum resolution achieved in the diffraction patterns is limited to 20-15 Å. Future work will need to address improved sample preparation protocols in order to assess whether diffraction to a resolution sufficient to permit structure solution can be obtained. Protein crystal formation in vivo has been observed under physiological or pathological conditions in a number of other systems [3]. We hope that our results will help to establish serial femtosecond X-ray diffraction (SFX) as a method for structural characterization of cellular structures with crystalline content and provide a proof of concept for using in situ crystallization of proteins as a means to generate nanocrystalline samples for SFX.

The Long-Wavelength MX Beamline I23 at Diamond Light Source

The long-wavelength macromolecular crystallography (MX) beamline I23 at Diamond Light Source will be the first dedicated beamline for long-wavelength phasing experiments from macromolecular crystals. By exploiting the weak anomalous differences from sulfur or phosphorous present in proteins or RNA/DNA molecules the crystallographic phase problem can be experimentally solved by anomalous diffraction methods based on their intrinsic signal without labeling the crystals with additional anomalous scatterers. Additionally, anomalous contrast can be used to unambiguously identify biologically important ions such as Ca2+, K+ or Cl-. The beamline will operate in a core wavelength range from 1.5 to 4 Å, offering a complementary setup to the suite of already five existing MX beamlines at Diamond. To minimize absorption effects, the complete beamline including sample, goniometer and detector will be operated in vacuum. An X-ray tomography setup will be integrated into the experimental end station to determine the crystal shape and size as a basis for an analytical absorption correction. A large curved Pilatus 12M detector will allow access to diffraction data up to 2theta =1100° (figure 1). Sample cooling is realized by a conductive path from a pulse tube cryo-cooler through the kappa goniometer. The beamline is currently in its construction phase with first users being expected in summer 2014. The challenges of in-vacuum long-wavelength macromolecular crystallography and the opportunities by extending the wavelength range towards the sulfur and phosphorous K-absorption edges will be discussed and an overview on the current status of the project will be given.

IDEEAA: A novel, versatile apparatus for electron spectroscopy

We report the development and present status of the iDEEAA (Instrument for Direct Electron Energy and Angular Analysis) experimental end station for time- and angle-resolved X-ray photoelectron spectroscopy. The setup is based on multidimensional detection of photoelectrons by means of both time-of-flight (TOF) and/or electrostatic analyzers. The instrument offers the possibility to record simultaneously and independently photoelectron and Auger electron spectra. Samples can be either gases or solids. The system can operate with multiple photon sources, such as laboratory-based table-top laser extreme ultraviolet (EUV) sources, monochromatic Helium discharge lamp and soft X-ray synchrotron pulses. We demonstrate the performance of the setup by carrying out electron–electron coincidence experiments on CH4 and by mapping the band structure of Bi2Se3 using photons of the BESSY II electron storage ring.

A hard X-ray nanospectroscopy station at SPring-8 BL39XU

We upgraded the hard X-ray spectroscopy beamline BL39XU at SPring-8 by installing Kirkpatrick-Baez mirrors to equip it with submicron-focusing capability. At the new experimental end-station located 74 m from the undulator source, an X-ray nanoprobe with a size of 120 × 100 nm2 has become available at 5–16 keV. This upgrade is fully compatible with the X-ray polarization tunability and helicity-switching between right- and left-circular polarizations; these are unique features of the beamline, which is equipped with a diamond X-ray phase retarder. A spatial resolution of ≈100 nm for X-ray absorption fine structure and X-ray magnetic circular dichroism (XMCD) spectroscopy has been achieved. We show a magnetization reversal process of an individual magnetic dot in bit-patterned perpendicular recording media using element-specific XMCD magnetization measurements to demonstrate the performance of the new station.

The nanotomography endstation at the PETRA III Imaging Beamline

The Imaging Beamline (IBL) operated by the Helmholtz-Zentrum Geesthacht (HZG) at the newly refurbished DESY PETRA III storage ring is dedicated to radiography and tomography and provides two experimental endstations, one for micro tomography and one for nano tomography. The technical specifications aim for 3D imaging with a spatial resolution of below 100 nm. This nanometer resolution will be achieved by using different combinations of compound refractive lenses as X-ray optics. In addition, a microscopic optic for magnifying the images after the converting in visible light will be used, too.The overall setup is designed to be very flexible, which allows also the implementation of other optical elements (e.g. Fresnel zoneplates, KB mirrors) as well as the application of different magnifying techniques like cone-beam tomography or X-ray microscopy. The accessible energy range for the nano tomography is 10 – 30 keV but the beamline is designed for an energy range of 5 – 50 keV and we aim to allow the same energy range for the nano tomography in the long run.

Study of time and pressure dependent phenomena at the hard x-ray beamline BL9 of DELTA

The beamline BL9 of DELTA (Dortmund ELecTron Accelerator) is a multi-purpose beamline operating in an energy range between 4 and 27 keV. A short overview of the beamline and the experimental endstation is given. Exemplarily three typical applications, namely x-ray diffraction from interfaces, small angle x-ray scattering under high hydrostatic pressure and fast x-ray reflectivity measurements, are discussed in some detail in order to demonstrate the capabilities of the beamline.

Beamline Design and Instrumentation for the Imaging and Coherence Beamline I13L at the Diamond Light Source

I13L is a 250 m long hard x-ray beamline (6 keV to 35 keV) at the Diamond Light Source. The beamline comprises of two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques. In this paper we will discuss the fundamental design concepts of the beamline and explain their implications for the civil engineering of the endstation building and the beamline instrumentation. For the latter this paper will focus on the beamline mirror systems and monochromators.

Characterization of radioactive materials using the MARS beamline at the synchrotron SOLEIL

Since 2004 numerous efforts have been done at the new French SOLEIL synchrotron to construct a beamline for studying radioactive matter in general and nuclear materials in particular. This Multi Analyses on Radioactive Samples (MARS) beamline has been designed and built thanks to a close partnership with the French Alternative Energies and Atomic Energy Commission (CEA). The optics and the experimental stations have been optimized to perform X-ray characterizations (diffraction, scattering, absorption spectroscopy and fluorescence imaging) on a large variety of radioactive elements. The special infrastructure of this beamline has been defined to be in conformity with the French safety regulations for the manipulation of relatively high activity samples (α, β, γ and n emitters) with an activity up to 18.5GBq per sample. Several relevant results obtained during the commissioning of the experimental end-stations are presented and discussed in the frame of the near future characterizations of nuclear materials by X-ray diffraction and absorption spectroscopy.

Dedicated beamlines for in-situ investigations of materials in reduced dimensions

Abstract The department for Low-Dimensional and Metastable Materials of the Max Planck Institute for Metals Research (newly renamed the Max Planck Institute for Intelligent Systems) designed and operates state-of-the art dedicated beamlines for the in-situ investigation of materials in reduced dimensions – the Max Planck Institute for Metals Research beamline at the synchrotron “Angstroem Quelle Karlsruhe”, ANKA, and the neutron/X-ray-contrast reflectometer N-REX+ at the research neutron source “Heinz Maier-Leibnitz”, FRM II in Garching. These beamlines offer unique possibilities for non-destructive and in-situ characterization of complex systems under technologically relevant conditions, providing information at the nanoscale. In this overview, we describe the most recent developments of the experimental end-stations and highlights of the research performed at the beamlines.

Modelling and design of the coherence and imaging beamline I13L at the Diamond Light Source

I13L is a 250 m long hard X-ray beamline (6–30 keV) currently under construction at the Diamond Light Source. The beamline comprises two independent experimental endstations: one for imaging in direct space using X-ray microscopy and one for imaging in reciprocal space using coherent diffraction-based imaging techniques. This paper will discuss the coherence branch, where well-defined coherence properties and preservation of the coherent flux are important. We will demonstrate the impact of optical components and stability onto the beamline performance, using phase-space-based ray-tracing techniques. The implications onto the beamline design will be demonstrated using our in-house build quadruple crystal monochromator as an example.

NIST NSLS-II spectroscopy beamline optical plan for soft and tender X-ray spectroscopy and microscopy (100eV to 7.5keV)

Abstract We describe the NIST multi-station beamline complex planned for NSLS-II. The beamline complex is based on two canted undulators, one for soft X-rays (0.1–2.0 keV) and one for tender X-rays (2–7.5 keV). The complex will have a total of six experimental stations, three on the soft X-ray branch and three on the tender X-ray branch, thereby serving a variety of soft and tender X-ray spectroscopy experiments. Two of the tender X-ray branch experimental endstations (HAXPES/NEXAFS and the XPS nanoscope) can be illuminated by both the soft and tender X-ray undulators, either sequentially or simultaneously, providing a continuous selection of X-rays from 100 eV to 7.5 keV. In this paper, the expected beamline performance at the XPS nanoscope endstation, for both the soft and tender X-ray sources, is presented.

Angle-resolved photoemission spectroscopy and imaging with a submicrometre probe at the SPECTROMICROSCOPY-3.2L beamline of Elettra

The extensive upgrade of the experimental end-station of the SPECTROMICROSCOPY-3.2L beamline at Elettra synchrotron light source is reported. After the upgrade, angle-resolved photoemission spectroscopy from a submicrometre spot and scanning microscopy images monitoring the photoelectron signal inside selected acquisition angle and energy windows can be performed. As a test case, angle-resolved photoemission spectroscopy from single flakes of highly oriented pyrolitic graphite and imaging of the flakes with image contrast owing to rotation of the band dispersion of different flakes are presented.

I20; the Versatile X-ray Absorption spectroscopy beamline at Diamond Light Source

The Versatile Spectroscopy beamline at Diamond Light Source, I20, is currently under construction and aims to begin operation in late 2009 and early 2010. The beamline aims to cover applications from physics, chemistry and biology through materials, environmental and geological science. Three very distinctive modes of operation will be offered at the beamline: scanning X-ray Absorption spectroscopy (XAS), XAS in dispersive mode, and X-ray emission spectroscopy (XES). To achieve this, the beamline has been designed around two independent experimental end-stations operating from a pair of canted wigglers located in a 5m diamond straight section. One branch of the beamline will deliver monochromatic x-ray radiation of high spectral purity to one of the experimental hutches, whilst the other branch will constitute an energy dispersive spectrometer. The novel design of the beamline allows both branches to operate simultaneously.

Vacuum ultraviolet beamline at the Swiss Light Source for chemical dynamics studies

A bend-magnet vacuum ultraviolet (VUV) beamline, intended for chemical dynamics studies, was constructed and brought into operation at the Swiss Light Source (SLS) of the Paul Scherrer Institut. The beamline delivers synchrotron radiation in the 5–30 eV photon energy range with a photon flux of 10 11 photons/s at 10 eV and 10 12 photons/s at 20 eV with a resolving power of 2500. The resolving power increases to 10 4 at the cost of photon flux. An in-house designed rare gas filter is used to suppress higher harmonic radiation by a factor of >10 4, yielding purely monochromatic light in the energy range of 5–21.6 eV. The filter is compact, easy to align, requires a total pumping power of less than 645 l/s and consumes only 3 normal l/h of filter gas. It is located at the end of the beamline, right in front of the experimental endstation. It is usually operated at a higher pressure than the endstation, which offers the additional benefit of protecting the beamline vacuum from sample contamination.

Single-shot timing measurement of extreme-ultraviolet free-electron laser pulses

Arrival time fluctuations of extreme-ultraviolet (EUV) pulses from the free-electron laser in Hamburg (FLASH) are measured single-pulse resolved at the experimental end-station. To this end, they are non-collinearly superimposed in space and time with visible femtosecond laser pulses on a GaAs substrate. The EUV irradiation induces changes of the reflectivity for the visible pulse. The temporal delay between the two light pulses is directly encoded in the spatial position of the reflectivity change which is captured with a CCD camera. For each single shot, the relative EUV/visible arrival-time can be measured with about 40 fs rms accuracy. The method constitutes a novel route for an improvement of future pump–probe experiments at short-wavelength free-electron lasers (FELs) by a pulse-wise correction with simultaneously measured arrival times of individual EUV pulses.

The small-angle and wide-angle X-ray scattering set-up at beamline BL9 of DELTA

The multi-purpose experimental endstation of beamline BL9 at the Dortmund Electron Accelerator (DELTA) is dedicated to diffraction experiments in grazing-incidence geometry, reflectivity and powder diffraction measurements. Moreover, fluorescence analysis and inelastic X-ray scattering experiments can be performed. Recently, a new set-up for small-angle and wide-angle X-ray scattering utilizing detection by means of an image-plate scanner was installed and is described in detail here. First small-angle X-ray scattering experiments on aqueous solutions of lysozyme with different cosolvents and of staphylococcal nuclease are discussed. The application of the set-up for texture analysis is emphasized and a study of the crystallographic texture of natural bio-nanocomposites, using lobster and crab cuticles as model materials, is presented.

The new HMI beamline MAGS: an instrument for hard X-ray diffraction at BESSY

The Hahn-Meitner-Institute Berlin is operating the new hard X-ray diffraction beamline MAGS at the Berlin synchrotron radiation source BESSY. The beamline is intended to complement the existing neutron instrumentation at the Berlin Neutron Scattering Centre. The new beamline uses a 7 T multipole wiggler to produce photon fluxes in the 10(11)-10(12) photons s(-1) (100 mA)(-1) (0.1% bandwidth)(-1) range at energies from 4 to 30 keV at the experiment. It has active bendable optics to provide flexible horizontal and vertical focusing and to compensate the large heat load from the wiggler source. The experimental end-station consists of a six-circle Huber diffractometer which can be used with an additional (polarization) analyser and different sample environments. The beamline is intended for single-crystal diffraction and resonant magnetic scattering experiments for the study of ordering phenomena, phase transitions and materials science.

The new diffractometer for surface X-ray diffraction at beamline BL9 of DELTA

The experimental endstation of the hard X-ray beamline BL9 of the Dortmund Electron Accelerator is equipped with a Huber six-circle diffractometer. It is dedicated to grazing-incidence X-ray diffraction and X-ray reflectivity experiments on solid surfaces and thin films as well as to powder diffraction measurements. A new set-up for grazing-incidence X-ray scattering of liquids has been built up using a silicon mirror to reflect the incident X-ray to the liquid surface at angles of incidence around the critical angle of total reflection of the sample. X-ray reflectivity measurements of a polymer film and grazing-incidence X-ray diffraction measurements of an epitaxically grown Gd40Y60 film, an oxidized surface of Fe-15at.%Al alloy and aqueous salt solutions are presented and discussed.

New Synchrotron Radiation Circular Dichroism end-station on DISCO beamline at SOLEIL synchrotron for biomolecular analysis

The novel Synchrotron Radiation Circular Dichroism (SRCD) technique is becoming a new tool of investigation for the molecular structures of biomolecules, like proteins, carbohydrates or others bio-materials. Here, we describe the characteristics of a new experimental end-station for circular dichroism studies, in construction on DISCO beamline at SOLEIL synchrotron (Saint-Aubin, France). This experimental end-station will be an open facility for the community of researchers in structural biology. In order to show the kind of information accessible with this type of technique, we give an example: the conformational study of the galactose mutarotase from Escherichia coli, an enzyme involved in the galactose metabolism. This study was made using an operational SRCD station available at SRS (Daresbury Laboratory, UK).