Falk T.J.,Max IV Laboratory
Synchrotron Radiation News | Year: 2014
The MAX IV Laboratory is a Swedish national laboratory hosted by Lund University, which provides X-rays over a wider range of energies for researchers from academia and industry as well as doing research and development in accelerator and nuclear physics. It operates the MAX I, II, and III storage rings in the present MAX-lab building and is building the new MAX IV facility on the outskirts of Lund, which will eventually replace the existing MAX-lab when it goes into operation in June 2016 (Figure 1). In this article, we will try to provide you with an update on the current activities with a strong focus on the exciting developments of the MAX IV project. © 2014 Copyright Taylor and Francis Group, LLC.
Einfeld D.,Max IV Laboratory
Synchrotron Radiation News | Year: 2014
One of the most important factors for synchrotron radiation research is the brilliance, typically defined as photon flux emitted into a unit solid angle from a unit source size within a defined relative bandwidth. The product of rms solid angle and source size yields the beam emittance. To reach high brilliance, both the horizontal and vertical beam emittance must be small and the stored beam current high. Even at zero emittance, radiative diffraction effects produce a finite volume of phase space of the radiation , with the effective photon beam emittance given by: (Figure presented.)where λ is the X-ray-wavelength and Eγ is the photon beam energy. In recent years, the user community has become increasingly interested in the transverse coherence properties of the X-ray beam. By using the half-Airy disk criterion , the coherent fraction of the emitted coherent light is given in Eq. (2), where εitot is the total emittance, including the contribution of the electron beam and the undulator radiation. ©, Copyright Taylor & Francis.
Klementiev K.,Max IV Laboratory |
Chernikov R.,German Electron Synchrotron
Journal of Physics: Conference Series | Year: 2016
We present a new implementation of the XAFSmass program that calculates the optimal mass of XAFS samples. It has several improvements as compared to the old Windows based program XAFSmass: 1) it is truly platform independent, as provided by Python language, 2) it has an improved parser of chemical formulas that enables parentheses and nested inclusion-to-matrix weight percentages. The program calculates the absorption edge height given the total optical thickness, operates with differently determined sample amounts (mass, pressure, density or sample area) depending on the aggregate state of the sample and solves the inverse problem of finding the elemental composition given the experimental absorption edge jump and the chemical formula.
Juanhuix J.,ALBA Synchrotron |
Gil-Ortiz F.,ALBA Synchrotron |
Cuni G.,ALBA Synchrotron |
Colldelram C.,ALBA Synchrotron |
And 8 more authors.
Journal of Synchrotron Radiation | Year: 2014
BL13-XALOC is currently the only macromolecular crystallography beamline at the 3 GeV ALBA synchrotron near Barcelona, Spain. The optics design is based on an in-vacuum undulator, a Si(111) channel-cut crystal monochromator and a pair of KB mirrors. It allows three main operation modes: a focused configuration, where both mirrors can focus the beam at the sample position to 52 μm × 5.5 μm FWHM (H × V); a defocused configuration that can match the size of the beam to the dimensions of the crystals or to focus the beam at the detector; and an unfocused configuration, where one or both mirrors are removed from the photon beam path. To achieve a uniform defocused beam, the slope errors of the mirrors were reduced down to 55 nrad RMS by employing a novel method that has been developed at the ALBA high-accuracy metrology laboratory. Thorough commissioning with X-ray beam and user operation has demonstrated an excellent energy and spatial stability of the beamline. The end-station includes a high-accuracy single-axis diffractometer, a removable mini-kappa stage, an automated sample-mounting robot and a photon-counting detector that allows shutterless operation. The positioning tables of the diffractometer and the detector are based on a novel and highly stable design. This equipment, together with the operation flexibility of the beamline, allows a large variety of types of crystals to be tackled, from medium-sized crystals with large unit-cell parameters to microcrystals. Several examples of data collections measured during beamline commissioning are described. The beamline started user operation on 18 July 2012. © 2014 International Union of Crystallography.
Sondhauss P.,Max IV Laboratory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
MASH stands for "Macros for the Automation of SHadow". It allows to run a set of ray-tracing simulations, for a range of photon energies for example, fully automatically. Undulator gaps, crystal angles etc. are tuned automatically. Important output parameters, such as photon flux, photon irradiance, focal spot size, bandwidth, etc. are then directly provided as function of photon energy. A photon energy scan is probably the most commonly requested one, but any parameter or set of parameters can be scanned through as well. Heat load calculations with finite element analysis providing temperatures, stress and deformations (Comsol) are fully integrated. The deformations can be fed back into the ray-tracing process simply by activating a switch. MASH tries to hide program internals such as file names, calls to pre-processors etc., so that the user (nearly) only needs to provide the optical setup. It comes with a web interface, which allows to run it remotely on a central computation server. Hence, no local installation or licenses are required, just a web browser and access to the local network. Numerous tools are provided to look at the ray-tracing results in the web-browser. The results can be also downloaded for local analysis. All files are human readable text files, that can be easily imported into third-party programs for further processing. All set parameters are stored in a single human-readable file in XML format. © 2014 SPIE.