A new optical scheme for large‐extraction small‐aberration vacuum‐ultraviolet synchrotron radiation beamlines

Vacuum‐ultraviolet radiation delivered by bending‐magnet sources is used at numerous synchrotron radiation facilities worldwide. As bending‐magnet radiation is inherently much less collimated compared with undulator sources, the generation of high‐quality intense bending‐magnet vacuum‐ultraviolet photon beams is extremely demanding in terms of the optical layout due to the necessary larger collection apertures. In this article, an optimized optical layout which takes into account both the optical and electron beam properties is proposed. This layout delivers an improved beam emittance of over one order of magnitude compared with existing vacuum‐ultraviolet bending‐magnet beamlines that, up to now, do not take into account electron beam effects. The arrangement is made of two dedicated mirrors, a cylindrical and a cone‐shaped one, that focus independently both the horizontal and the vertical emission of a bending‐magnet source, respectively, and has been already successfully applied in the construction of the infrared beamline at the Brazilian synchrotron. Using this scheme, two vacuum‐ultraviolet beamline designs based on a SOLEIL synchrotron bending‐magnet source are proposed and analysed. They would be useful for future upgrades to the DISCO beamline at SOLEIL and could be readily implemented at other synchrotron radiation facilities.     

Compact IR synchrotron beamline design

Third‐generation storage rings are massively evolving due to the very compact nature of the multi‐bend achromat (MBA) lattice which allows amazing decreases of the horizontal electron beam emittance, but leaves very little place for infrared (IR) extraction mirrors to be placed, thus prohibiting traditional IR beamlines. In order to circumvent this apparent restriction, an optimized optical layout directly integrated inside a SOLEIL synchrotron dipole chamber that delivers intense and almost aberration‐free beams in the near‐ to mid‐IR domain (1–30 µm) is proposed and analyzed, and which can be integrated into space‐restricted MBA rings. Since the optics and chamber are interdependent, the feasibility of this approach depends on a large part on the technical ability to assemble mechanically the optics inside the dipole chamber and control their resulting stability and thermo‐mechanical deformation. Acquiring this expertise should allow dipole chambers to provide almost aberration‐free IR synchrotron sources on current and `ultimate' MBA storage rings.     

Advantages of a synchrotron bending magnet as the sample illuminator for a wide‐field X‐ray microscope

In this paper the choice between bending magnets and insertion devices as sample illuminators for a hard X‐ray full‐field microscope is investigated. An optimized bending‐magnet beamline design is presented. Its imaging speed is very competitive with the performance of similar microscopes installed currently at insertion‐device beamlines. The fact that imaging X‐ray microscopes can accept a large phase space makes them very well suited to the output characteristics of bending magnets which are often a plentiful and paid‐for resource. There exist opportunities at all synchrotron light sources to take advantage of this finding to build bending‐magnet beamlines that are dedicated to transmission X‐ray microscope facilities. It is expected that demand for such facilities will increase as three‐dimensional tomography becomes routine and advanced techniques such as mosaic tomography and XANES tomography (taking three‐dimensional tomograms at different energies to highlight elemental and chemical differences) become more widespread.     

Performance of the infrared microspectroscopy station at SSRF

At the third generation synchrotron light source Shanghai Synchrotron Radiation Facility (SSRF), the first infrared beamline BL01B has been successfully constructed. The infrared beamline collects both bending magnet and edge radiation. A brief introduction of the infrared beamline design has been given in this article. The infrared microspectroscopy station is equipped with a Nicolet 6700 FTIR spectrometer and a Nicolet Continuum Microscope. The flux at the entrance of the FTIR spectrometer, the intensity profile, the signal to noise ratio (SNR) with different apertures, and the focused spot size of the infrared microspectroscopy station have been measured. The performances with synchrotron radiation infrared source and internal globar source have been compared. The results indicate that the infrared microspectroscopy station at SSRF has the ability of analysis samples in a small area with diffraction limited spatial resolution.     

Infrared facility at the Canadian light source

The Canadian Light Source (CLS) is constructing two beamlines for Infrared Spectroscopy using synchrotron radiation (IRSR). One will supply mid-Infrared (2–25 μ) light to a Fourier Transform Infrared (FTIR) spectrometer and microscope for biological applications. The second will have a high resolution FTIR spectrometer for gas-phase and surface spectroscopy in the far-Infrared (beyond 25 μ). The Infrared beamlines will use dipole bending magnet radiation from a special bend magnet port design which provides a 50 mrad square acceptance. Issues with the first mirror and photon mask design, as well as the beamline layout and features are discussed.     

Investigations of mechanical vibrations for beamlines at the Canadian Light Source

Vibration is often a problem causing poor quality of photon beams at synchrotron radiation facilities, since beamlines are quite sensitive to vibrations. Therefore, vibration analysis and control at synchrotron radiation facilities is crucial. This paper presents investigations on mechanical vibrations at four beamlines and endstations at the Canadian Light Source, i.e. the Canadian Macromolecular Crystallography Facility 08ID‐1 beamline, the Hard X‐ray MicroAnalysis 06ID‐1 beamline, the Resonant Elastic and Inelastic Soft X‐ray Scattering 10ID‐2 beamline, and the Scanning Transmission X‐ray Microscope endstation at the Spectromicroscopy 10ID‐1 beamline. This study identifies vibration sources and investigates the influence of mechanical vibrations on beamline performance. The results show that vibrations caused by movable mechanical equipment significantly affect the data acquired from beamlines.     

The synchrotron infrared beamline SISSI at ELETTRA

The infrared synchrotron radiation emitted from a bending magnet of the third generation storage ring ELETTRA is studied in detail by ray-tracing techniques. Constant magnetic-field and edge infrared emissions are taken into account in the project of the bending vacuum chamber and on the beamline design. Moreover the gain in flux and brightness with respect to a conventional source of the infrared radiation are calculated and discussed.     

ALBA Synchrotron Facility

ALBA is the Spanish synchrotron facility located in the area of Barcelona. It is a low-emittance, 3 GeV machine having, at present, seven state-of-the-art operating beamlines covering soft and hard X-rays. The hard X-ray beamlines comprise macromolecular crystallography, non-crystalline diffraction (SAXS and WAXS), high-resolution powder diffraction, and absorption spectroscopy. The soft X-ray beamlines include a photoemission beamline with two endstations—one devoted to photoelectron microscopy (PEEM) and the second to near ambient pressure photoemission (NAPP)—and another beamline devoted to XMCD and soft X-ray scattering. Both beamlines allow full control of the polarization of the beam, since they are equipped with helical undulators. An additional soft X-ray beamline, installed on a bending magnet port, is equipped with a full-field transmission X-ray microscope. Additional information may be found at http://www.albasynchrotron.es/en/beamlines.     

Microcrystallography using single‐bounce monocapillary optics

X‐ray microbeams have become increasingly valuable in protein crystallography. A number of synchrotron beamlines worldwide have adapted to handling smaller and more challenging samples by providing a combination of high‐precision sample‐positioning hardware, special visible‐light optics for sample visualization, and small‐diameter X‐ray beams with low background scatter. Most commonly, X‐ray microbeams with diameters ranging from 50 µm to 1 µm are produced by Kirkpatrick and Baez mirrors in combination with defining apertures and scatter guards. A simple alternative based on single‐bounce glass monocapillary X‐ray optics is presented. The basic capillary design considerations are discussed and a practical and robust implementation that capitalizes on existing beamline hardware is presented. A design for mounting the capillary is presented which eliminates parasitic scattering and reduces deformations of the optic to a degree suitable for use on next‐generation X‐ray sources. Comparison of diffraction data statistics for microcrystals using microbeam and conventional aperture‐collimated beam shows that capillary‐focused beam can deliver significant improvement. Statistics also confirm that the annular beam profile produced by the capillary optic does not impact data quality in an observable way. Examples are given of new structures recently solved using this technology. Single‐bounce monocapillary optics can offer an attractive alternative for retrofitting existing beamlines for microcrystallography.     

High‐spatial‐resolution mapping of superhydrophobic cicada wing surface chemistry using infrared microspectroscopy and infrared imaging at two synchrotron beamlines

The wings of some insects, such as cicadae, have been reported to possess a number of interesting and unusual qualities such as superhydrophobicity, anisotropic wetting and antibacterial properties. Here, the chemical composition of the wings of the Clanger cicada (Psaltoda claripennis) were characterized using infrared (IR) microspectroscopy. In addition, the data generated from two separate synchrotron IR facilities, the Australian Synchrotron Infrared Microspectroscopy beamline (AS‐IRM) and the Synchrotron Radiation Center (SRC), University of Wisconsin‐Madison, IRENI beamline, were analysed and compared. Characteristic peaks in the IR spectra of the wings were assigned primarily to aliphatic hydrocarbon and amide functionalities, which were considered to be an indication of the presence of waxy and proteinaceous components, respectively, in good agreement with the literature. Chemical distribution maps showed that, while the protein component was homogeneously distributed, a significant degree of heterogeneity was observed in the distribution of the waxy component, which may contribute to the self‐cleaning and aerodynamic properties of the cicada wing. When comparing the data generated from the two beamlines, it was determined that the SRC IRENI beamline was capable of producing higher‐spatial‐resolution distribution images in a shorter time than was achievable at the AS‐IRM beamline, but that spectral noise levels per pixel were considerably lower on the AS‐IRM beamline, resulting in more favourable data where the detection of weak absorbances is required. The data generated by the two complementary synchrotron IR methods on the chemical composition of cicada wings will be immensely useful in understanding their unusual properties with a view to reproducing their characteristics in, for example, industry applications.     

The high‐resolution diffraction beamline P08 at PETRA III

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.     

A sagittally focusing double‐multilayer monochromator for ultrafast X‐ray imaging applications

The development of a sagittally focusing double‐multilayer monochromator is reported, which produces a spatially extended wide‐bandpass X‐ray beam from an intense synchrotron bending‐magnet source at the Advanced Photon Source, for ultrafast X‐ray radiography and tomography applications. This monochromator consists of two W/B₄C multilayers with a 25 Å period coated on Si single‐crystal substrates. The second multilayer is mounted on a sagittally focusing bender, which can dynamically change the bending radius of the multilayer in order to condense and focus the beam to various points along the beamline. With this new apparatus, it becomes possible to adjust the X‐ray beam size to best match the area detector size and the object size to facilitate more efficient data collection using ultrafast X‐ray radiography and tomography.     

Noise reduction efforts for the ALS infrared beamlines

The quality of infrared microscopy and spectroscopy data collected at synchrotron based sources is strongly dependent on signal-to-noise. We have successfully identified and suppressed several noise sources affecting beamlines 1.4.2, 1.4.3, and 1.4.4 at the advanced light source (ALS), resulting in a significant increase in the quality of FTIR spectra obtained. In this paper, we present our methods of noise source analysis, the negative effect of noise on the infrared beam quality, and the techniques used to reduce the noise. These include reducing the phase noise in the storage ring radio-frequency (RF) system, installing an active mirror feedback system, analyzing and changing physical mounts to better isolate portions of the beamline optics from low-frequency environmental noise, and modifying the input signals to the main ALS RF system. We also discuss the relationship between electron beam energy oscillations at a point of dispersion and infrared beamline noise.     

Energy-dispersive X-ray diffraction beamline at Indus-2 synchrotron source

An energy-dispersive X-ray diffraction beamline has been designed, developed and commissioned at BL-11 bending magnet port of the Indian synchrotron source, Indus-2. The performance of this beamline has been benchmarked by measuring diffraction patterns from various elemental metals and standard inorganic powdered samples. A few recent high-pressure investigations are presented to demonstrate the capabilities of the beamline.     

Design,development and first experiments on the X‐ray imaging beamline at Indus‐2 synchrotron source RRCAT,India

A full‐field hard X‐ray imaging beamline (BL‐4) was designed, developed, installed and commissioned recently at the Indus‐2 synchrotron radiation source at RRCAT, Indore, India. The bending‐magnet beamline is operated in monochromatic and white beam mode. A variety of imaging techniques are implemented such as high‐resolution radiography, propagation‐ and analyzer‐based phase contrast imaging, real‐time imaging, absorption and phase contrast tomography etc. First experiments on propagation‐based phase contrast imaging and micro‐tomography are reported.     

The first microbeam synchrotron X‐ray fluorescence beamline at the Siam Photon Laboratory

The first microbeam synchrotron X‐ray fluorescence (µ‐SXRF) beamline using continuous synchrotron radiation from Siam Photon Source has been constructed and commissioned as of August 2011. Utilizing an X‐ray capillary half‐lens allows synchrotron radiation from a 1.4 T bending magnet of the 1.2 GeV electron storage ring to be focused from a few millimeters‐sized beam to a micrometer‐sized beam. This beamline was originally designed for deep X‐ray lithography (DXL) and was one of the first two operational beamlines at this facility. A modification has been carried out to the beamline in order to additionally enable µ‐SXRF and synchrotron X‐ray powder diffraction (SXPD). Modifications included the installation of a new chamber housing a Si(111) crystal to extract 8 keV synchrotron radiation from the white X‐ray beam (for SXPD), a fixed aperture and three gate valves. Two end‐stations incorporating optics and detectors for µ‐SXRF and SXPD have then been installed immediately upstream of the DXL station, with the three techniques sharing available beam time. The µ‐SXRF station utilizes a polycapillary half‐lens for X‐ray focusing. This optic focuses X‐ray white beam from 5 mm × 2 mm (H × V) at the entrance of the lens down to a diameter of 100 µm FWHM measured at a sample position 22 mm (lens focal point) downstream of the lens exit. The end‐station also incorporates an XYZ motorized sample holder with 25 mm travel per axis, a 5× ZEISS microscope objective with 5 mm × 5 mm field of view coupled to a CCD camera looking to the sample, and an AMPTEK single‐element Si (PIN) solid‐state detector for fluorescence detection. A graphic user interface data acquisition program using the LabVIEW platform has also been developed in‐house to generate a series of single‐column data which are compatible with available XRF data‐processing software. Finally, to test the performance of the µ‐SXRF beamline, an elemental surface profile has been obtained for a piece of ancient pottery from the Ban Chiang archaeological site, a UNESCO heritage site. It was found that the newly constructed µ‐SXRF technique was able to clearly distinguish the distribution of different elements on the specimen.     

Phase‐space analysis and experimental results for secondary focusing at X‐ray beamlines

Micro‐focusing optical devices at synchrotron beamlines usually have a limited acceptance, but more flux can be intercepted if such optics are used to focus secondary sources created by the primary optics. Flux throughput can be maximized by placing the secondary focusing optics close to or exactly at the secondary source position. However, standard methods of beamline optics analysis, such as the lens equation or matching the mirror surface to an ellipse, work poorly when the source‐to‐optics distance is very short. In this paper the general characteristics of the focusing of beams with Gaussian profiles by a `thin lens' are analysed under the paraxial approximation in phase space, concluding that the focusing of a beam with a short source‐to‐optics distance is distinct from imaging the source; slope errors are successfully included in all the formulas so that they can be used to calculate beamline focusing with good accuracy. A method is also introduced to use the thin‐lens result to analyse the micro‐focusing produced by an elliptically bent trapezoid‐shaped Kirkpatrick–Baez mirror. The results of this analysis are in good agreement with ray‐tracing simulations and are confirmed by the experimental results of the secondary focusing at the 18‐ID Bio‐CAT beamline (at the APS). The result of secondary focusing carried out at 18‐ID using a single‐bounce capillary can also be explained using this phase‐space analysis. A discussion of the secondary focusing results is presented at the end of this paper.     

Calculation of Transmitted Efficiency and Output Characteristics for Beijing Synchrotron Radiation Facility (BSRF) 3B3 Beamline

Based on the radiation characteristics of the bend magnet source, the output characteristics of the BSRF-3B3 beamline was analyzed and discussed. The result is the foundation of adjustment and diagnosis of the beamline. A calculation model is provided to analyze characteristics of beamlines attached to bend magnet sources.