Synchrotron X-ray-enhanced scanning tunnelling microscopy (SXSTM) is a novel technique by which materials can be studied with elemental-sensitive and nanometre-spatial resolution. This poster covers the mechanical engineering design for the prototype SXSTM instrument. System performance and sample handling requirements along with the desire to use existing components constrained the design. The SXSTM needs to be mechanically and acoustically isolated from the environment. In addition, all sample preparations are done in situ, and thus, the sample and SXSTM tips need to be prepared and moved inside the vacuum chamber with a wobble stick. The final design incorporates an Advanced Photon Source-designed vacuum chamber, existing components and commercial parts to provide the user with a robust prototype system to demonstrate the impact of this new technique.

Diamond Light Source (DLS) is undertaking a programme of developing additional photon beamlines to be added to the existing facility. Operating in the UK, DLS is subject to the Ionizing Radiation Regulations, (IRR99) and having been elected to follow the path of generic prior authorization, DLS is obliged to implement a personnel safety system that conforms to the Approved Code of Practice. In addition, DLS has strived to apply EN61508 to the management and design of the system. This presentation will explain the constraints, design elements and the process that we have undertaken to implement each new safety system and its incorporation into the existing system.

A prototype of a new double crystal monochromator (DCM) has been designed and developed for the second crystallography beamline (XRD2) at ELETTRA. The new device has to cover the 8–35 keV X-ray range. Since the corresponding diffraction angles are quite small, the choice has been to design a DCM with a fixed distance between the two crystals. As a consequence, the output beam has a small vertical displacement during the scan. This movement is compensated by means of an upstream mask, vertically moving and cutting the input beam at different heights. The movement of the mask is driven by a mechanism linked to the primary rotation of crystals (self-compensation), without any additional motor and following the displacement law required for compensation. The principle, the mechanism and the general mechanical concept of the device will be described in this paper.

ALBA synchrotron light facility includes a 3 GeV low-emittance storage ring capable of running in the top-up mode which will feed a number of beamlines. Xaloc and CIRCE are among these beamlines. These beamlines are equipped with mirrors which need high stability. There are a lot of mirror chambers in the market and we decided to improve one of them rather than developing a new one. For this purpose, the ALBA team organized a collaboration with a supplier of beamline components. ALBA did the conceptual design of the improvements, the Finite Element Analysis (FEA) optimization and the metrology tests. The supplier provided a detailed design and the production. The improvement was implemented on several mirror chambers including actuators from two to five degrees of freedom. At the beginning of the project, the hypothesis was an excitation coming from the ground lower than 1 µm for frequencies below 45 Hz and negligible above it. The strategy[0] in terms of dynamical stability was not to amplify the ground excitation below 45 Hz or around 50 Hz. That is, to increase the frequency of the system resonances above 45 Hz (excluding the range of about 50 Hz). As a result, we obtained a high level of stability for such mirror systems and we almost met the target value for the first mode of vibration.

National Synchrotron Radiation Research Center (NSRRC) in Taiwan has initialized the construction of Taiwan Photon Source (TPS) synchrotron accelerator project. This 3 GeV, 500 mA beam current third-generation synchrotron accelerator will have a total of seven insertion device beam lines at day 1 after commissioning. That is, there will be one 2 × EPU48, five IU22 and one U5 undulator beamline. Corresponding front end components such as fixed masks, photon beam position monitor, photon absorber, slits and heavy metal shutter have been designed; manufacturing of these subsystems are on the way. Several prototype assemblies are completed, tested and will be reported in this paper.

An instrument for X-ray emission spectroscopy (XES) based on perfect crystal Bragg optics was recently commissioned at beam line ID26 of the ESRF (European Synchrotron Radiation Facility). The spectrometer is used to record high-energy resolution fluorescence-detected X-ray absorption spectra with sub-lifetime resolution and to perform resonant and non-resonant XES. The hard X-ray probe is material bulk sensitive and allows demanding sample environments (in situ chemistry, high pressure, etc.). Spectrometers for XES are being installed or designed at almost all upcoming synchrotron radiation sources worldwide. The particularity of the ID26 spectrometer is to accommodate five analyser crystals with exact Rowland tracking in the vertical plane and with crystals radii between 0.5 and 2 m.The main upgrade of the new version of this large instrument (3 tonnes, overall size 2.5 m and height 3 m) is to allow the change of the scattering angle over the range 0–180°. This involves rotating the entire spectrometer around a vertical axis that passes through the sample. In order to optimize the vibration stability of the spectrometer's structure, we chose to support the structure in multiple points and not only on three (kinematic mount) like it is specified to do with air pads. According to this choice, we have developed special foot holders for air pads.The calculations during the design phase have shown that we can obtain a first modal frequency of the spectrometer's structure at more than 30 Hz. To confirm our predictive calculations, we have performed some vibration measurements.

Since 2007, we have offered single collimators for mini beams of sizes 5, 10 and 20 µm as well as a 300 µm scatter-guard to accommodate the fully focused beam. The advantages of varying the beam size were obvious, better signal/background ratio and the capability to raster with a coarse, larger beam, then fine tune with one of the mini-beam options. The mini beams proved to be a technical and popular success; however, the switching of the single collimators often involved staff intervention. The single mini-beam collimators were the precursors to the development of a triple collimator. This implementation incorporated two mini-beam collimators and a 300 µm scatter-guard on one post. The design was improved by consolidation of fabrication from a single piece of molybdenum block. It significantly improved the robustness, ease of initial alignment, reduction of background and increased automation. However, experimenters were still left with a choice of either a (5, 10 and 300 µm)- or a (10, 20 and 300 µm)-triple collimator. Recently, a quad collimator was developed and fabricated to provide a selection of mini beams of 5, 10 and 20 µm and a 300 µm scatter-guard, on a single post. We will present the mechanical design of multi-collimators, results of measured beam flux through the collimator pinholes.

In the diffraction community, the goniometer is the main part of the diffractometer, essential for orienting the samples. To characterize the goniometer, the sphere of confusion (SoC) has been measured. The SoC describes the minimal sphere that enclosed the measurements. This essential information is very important for the diffractometer users. In collaboration with Symetrie Inc., Soleil Synchrotron and the CEA, the SoC has been measured with three different metrology methods. These three measurement techniques and the associated results are discussed in this article.

The Advanced Photon Source at Argonne National Laboratory is developing a low-emittance thermionic gun for a proposed X-ray free-electron laser oscillator (XFEL-O) that will use a laser pulse-heated cathode. The cathode must operate at or slightly above 1500 °C for several nanoseconds and then cool down several hundred °C in approximately the same amount of time, with a 1-MHz heating–cooling cycle. A transient thermal analysis was performed to optimize the laser pulse shape needed to provide the desired temperature response of the cathode for several possible cathode materials. In addition, thermal stresses developed in the cathode during heating–cooling cycles were analysed. Both transient thermal analysis and thermal stress computations were performed using the ANSYS12 code. The computed temperature distribution and thermal stresses were utilized in the optimization of the cathode design. The results of the analysis are presented.

The main foot bridge provides access to linac, booster and storage ring facilities in the synchrotron of Diamond Light Source. The impact of the passage of pedestrian traffic and equipment across the bridge structure was noticeable to the site of beamlines below. One of them, I20, is the most sensitive beamline to such impact. The bridge obviously oscillated with even light traffic, and it was also assumed that this would couple to the storage ring structure where the bridge is mounted. The optics for beamline I20, for stability, stands directly on the slab within the I20 experimental area; this was however subject to excessive vibration transmitted by foot traffic from the overhead footbridge producing a vibration on the experimental floor of 86 nm whereas elsewhere in the experimental hall experiences only about 20 nm, demonstrating a four times increase in vibration caused by the pedestrian bridge. Vibration measurements on the ground underneath the bridge and finite element analyses clearly show that frequencies of 2 and 5 Hz were caused by the bridge and traffic on it. Several remedies were proposed. However, dampers will only damp out vibrations of around 5–6 Hz but not to damp out 2 Hz, which is caused directly by human foot steps. After investigation of cost and effectiveness and several vibration tests conducted, a compromise with extra propping at the mid-span of the bridge was eventually selected. Such reinforcement has been now implemented. The 5 Hz frequency has been successfully removed and a amplitude of 2 Hz also considerably reduced.

National Synchrotron Light Source II (NSLS-II) will be a 3-GeV, 792-m circumference third-generation synchrotron radiation facility with ultralow emittance and extremely high brightness. Front ends are required to transmit synchrotron radiation from the storage ring to the beam line while providing equipment and personnel protection. There will be up to 57 front ends in the NSLS-II facility with six in the baseline. Original designs are being developed and will be manufactured for three non-canted in-vacuum undulators, one canted in-vacuum undulator, one elliptically polarized undulator and one damping wiggler. Bending magnet and three-pole wiggler front ends are also being designed. Power densities range from 0.3 to 89.8 kW mrad−2, with total powers ranging from 0.34 to 64.5 kW. All components intercepting synchrotron radiation are water cooled and were analysed to confirm acceptable thermal limits.

Compact linear collider (CLIC) is a study for a future electron–positron collider that would allow physicists to explore a new energy region beyond the capabilities of today's particle accelerators. The demanding transverse and vertical beam sizes and emittance specifications are resulting in stringent alignment and a nanometre stability requirement. In the current feasibility study, the main beam quadrupole magnets have to be actively pre-aligned with a precision of 1 µm in five degrees of freedom before being mechanically stabilized to the nanometre scale above 1 Hz. This contribution describes the approach of performing this active pre-alignment based on an eccentric cam system. In order to limit the amplification of the vibration sources at resonant frequencies, a sufficiently high eigenfrequency is required. Therefore, the contact region between cam and support was optimized for adequate stiffness based on the Hertzian theory. Furthermore, practical tests performed on a single-degree-of-freedom mockup will show the limitation factors and further improvements required for successful integration in a full-scale quadrupole mockup presently under design.

Taiwan Photon Source (TPS), a new 3 GeV synchrotron ring, is under construction at National Synchrotron Radiation Research Center (NSRRC). To discover problems of design, manufacture and installation, a mockup of 1/24 section (one cell) of TPS was installed at NSRRC. A modified, precise, six-axis, prototype girder system of this mockup composed of three girders was fabricated. We discuss both the installation of the girder system and its diagnostics, and present the results including measurement of the dimensions of the components of the girder system and the vibration tests.

National Synchrotron Radiation Research Center, Taiwan, is currently constructing the civil buildings and utility system of the Taiwan Photon Source. The air conditioning (AC) system of the storage ring tunnel was designed based on those of existing Taiwan Light Source and some international advanced accelerators. To predict the air temperature variation and flow pattern in tunnel more precisely, we applied 3D computational fluid dynamics scheme and built up a one-cell mock-up equipped with AC system. In the 3D numerical model, effects of magnets of the booster and the storage ring, girders, cable trays, front ends and the supplied air wind duct are all taken into account. The temperature variations and flow pattern were shown through the numerical simulation. Measured air temperature data in the one-cell mock-up were also collected.

For the beamlines of the new synchrotron radiation source PETRA III, fixed-exit double crystal monochromators with specific features were developed. To achieve a compact arrangement of the canted undulator beamlines at Sectors 2, 4 and 6, it is necessary to shift one of the two beamlines in vertical direction. This is done by so-called large offset monochromators. Two of these monochromators (LOM500 and Mono-P06) accept the white beam and are therefore cooled with liquid nitrogen. The third one accepts a monochromatic beam and has no cooling system. The challenge with this device (LOM1250) is the large offset of the beam by 1.25 m. The energy range in combination with the large vertical beam offset demands for a relative crystal movement of roughly 3 m along the beam direction. This is implemented by translating each crystal by up to 1.5 m. It is equipped with a visible laser-based stabilization which allows compensating thermal drift of the mechanical components involved in the positioning of the crystals. With this novel approach the X-ray beam is not attenuated by beam position monitors.

A precise laser positioning system had been preliminarily developed for the girder system of the Taiwan Photon Source. This laser positioning system, a part of a girder auto-alignment scheme, will be installed on the girders located at both sides of each straight section of the storage ring. The system is composed of a laser and four sets of a position sensing device (PSD). The laser, held on one girder, propagates 13 m along the girder and plays the role of a reference line of girders of the straight section. Based on the laser linear characteristics, the other girder can be adjusted and aligned by a cam mover according to PSD data. To achieve superior precision, the whole laser positioning system should be constructed stably. After making some improvements to eliminate the unstable terms, the precision of the laser positioning system can achieve 2 µm at 13 m propagating distance every 4 h.

Taiwan Photon Source is a new 3-GeV ring with characteristics of great brightness and small emittance, at present under construction at National Synchrotron Radiation Research Center (NSRRC) site in Taiwan and due to be commissioned in 2013. The positioning of the magnets is highly sensitive to alignment errors, and the entire building will be constructed half underground at depth 12 m relative to Taiwan Light Source (TLS) for stability reasons; for these reasons the survey and alignment work is confined and difficult. To position magnets precisely and quickly, a highly accurate auto-tuning girder system combined with a survey network was designed to accomplish the alignment tasks. The survey network includes a preliminary Global Positioning System (GPS) network and a laser-tracking network. The position data from the survey network define a basis for the system of motorized girders to auto-tune and improve the accuracy. The detailed survey and alignment design, simulation and preliminary data are described in this paper.

The ESRF has now started its upgrade programme. It has become evident from the start that upgrading beamline performance implies upgrading component performance. Beam stability is seen as a key requirement for many of the proposed beamlines, but the source of (in)stabilities can be manyfold. However, one identified source is white beam mirror, and therefore, ESRF has recently invested significant amount of engineering effort to improve white beam mirror performance. The motivation for having ‘ultra stable mirrors’ at the upgrade beamline ID24 Dispersive Exafs is analysed. The design solutions for positioning, cooling and supporting the white beam mirrors for this project are presented.

New trends in X-ray crystallography are concerned with the study of transient conditions of atomic structures, which take place after an energy activation agent is introduced. These time-resolved experiments require a fast mechanical shutter to interrupt the X-ray beam in a pump–probe cycle, with the aim to generate a stroboscopic effect. Thus, only diffraction data that are representative of the activated structure are actually collected. A rotating type of shutter, also known as chopper, is presented with the purpose to enable time-resolved experiments to be performed at I19 small-molecule single-crystal diffraction beamline. Exceptional stability in the rotational speed is critical to achieve the desired stroboscopic effect with minimum jitter. This requirement can be addressed only through design by the specification of suitable components and implementation of high-precision methods in manufacturing. The proposed equipment is comprised of a spindle supported on air bearings coupled to a slotted disc rotating inside a vacuum enclosure and driven by a brushless servo motor. Advanced control features are proposed to ensure that speed stability is achieved. Preliminary tests produced very encouraging results, giving strong indication that the chopper satisfies the specifications required for time-resolved experiments.

For some beamlines, where the X-ray beam is focussed to less than 100 nm spot size, it is necessary to rotate the sample using very accurate rotary axes. The accuracy of these devices is defined in terms of radial, axial and tilt errors. At the Precision Engineering Laboratory of the ESRF, we are able to calibrate rotary stages and spindles in agreement with the ISO 230-7 and ASME B89.3.4 standards, in static mode (step by step, at given position increments) or in continuous motion. This type of measurement is possible through the use of non-contact capacitive sensors (with measuring resolution in the field of the nanometre) and reference spherical artefacts, working under controlled environmental conditions to minimize the influence of thermal instabilities. The setup includes a special granite stage with a gantry, supported by an active anti-vibration system. The presentation will illustrate the measurement principle and some examples of calibrations, including results obtained on a motorized air-bearing rotary stage for which the measured errors are about 20 nm.