| 1. |
- Bahrdt, Johannes, et al.
(författare)
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Propagation of Coherent Light Pulses with PHASE
- 2014
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Ingår i: [Host publication title missing]. - : SPIE.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The current status of the software package PHASE for the propagation of coherent light pulses along a synchrotron radiation beamline is presented. PHASE is based on an asymptotic expansion of the Fresnel-Kirchhoff integral (stationary phase approximation) which is usually truncated at the 2nd order. The limits of this approximation as well as possible extensions to higher orders are discussed. The accuracy is benchmarked against a direct integration of the Fresnel-Kirchhoff integral. Long range slope errors of optical elements can be included by means of 8th order polynomials in the optical element coordinates w and l. Only recently, a method for the description of short range slope errors has been implemented. The accuracy of this method is evaluated and examples for realistic slope errors are given. PHASE can be run either from a built-in graphical user interface or from any script language. The latter method provides substantial flexibility. Optical elements including apertures can be combined. Complete wave packages can be propagated, as well. Fourier propagators are included in the package, thus, the user may choose between a variety of propagators. Several means to speed up the computation time were tested - among them are the parallelization in a multi core environment and the parallelization on a cluster.
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| 2. |
- Grizolli, Walan, et al.
(författare)
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Multilayer based soft-x-ray polarimeter at MAX IV Laboratory.
- 2016
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 1089-7623 .- 0034-6748. ; 87:2
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Tidskriftsartikel (refereegranskat)abstract
- A high precision five rotation-axes polarimeter using transmission multilayers as polarizers and reflection multilayers as analyzers has been designed and manufactured. To cover the extreme ultraviolet regime, Mo/Si, Cr/C, Sc/Cr, and W/B4C multilayers for transmission and reflection have also been designed and produced. The polarimeter mechanics is supported on a hexapod to simplify the alignment relative to photon beam. The instrument is designed so that it can be easily transferred between different beamlines.
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| 3. |
- Grizolli, Walan
(författare)
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Optical Studies For Synchrotron Radiation Beamlines
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Synchrotron radiation sources have greatly contributed to the progress in many fields of science. The development of the storage ring technologies has made possible to obtain very low emittance electron beams, which together with the use of undulators allow guiding a very high photon flux into a very small spot required by the experiments. Development of the sources has been accompanied with equally strong progress in beamline optics, improving further experimental conditions and opening new possibilities in science. This follows from the fact that beamlines have to transport the photon beam from the source to the experiment while conserving the beam quality and the photon flux of the source as good as possible. This work uses basic concepts of X-ray optics to develop beamlines and beamline instrumentation. First, a beamline design that uses astigmatism is discussed. This project takes advantage of the low vertical emittance of the MAX II and MAX IV storage rings to improve the flexibility of soft X-ray beamlines. Secondly a polarimeter is introduced, a device that characterizes the polarization of the light at the experimental station. In this part a new method is presented for analyzing the polarimeter data. Finally, applying wave optics to X-ray optics is presented and discussed. It is shown how new tools were added into wave propagation modeling, taking into account surface errors of the optical components used in grazing incidence. For these studies the source properties, X-ray interaction with matter together with many concepts in optics are needed and are also presented here.
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| 4. |
- Grizolli, Walan
(författare)
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Studies of X-Ray Optics And Polarimetry For Synchrotron Radiation
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Synchrotron radiation sources have greatly contributed to the progress in many fields of science. The development of the storage ring technologies have made possible to obtain very low emittance electron beams, which together with the use of undulators allow to guide a very high photon flux into a very small beam size required by the experiments. Development of sources has been accompanied with equally strong progress in beamline optics, improving further the experiments and opening new possibilities in science. This follows from the fact that beamlines have to transport the photon beam from the source to the experiment while conserving the beam quality and the photon flux of the source as good as possible. This work uses basics concepts of X-ray optics to develop beamlines and beamline instrumentation. First, a beamline design that uses astigmatism is discussed. This project takes advantage of the low vertical emittance of the MAX~II storage ring to improve the flexibility of soft X-ray beamlines. Secondly a polarimeter is introduced, a device that characterizes the polarization of the light at the experimental station. In this part a novel method is presented for analyzing the polarimeter data. For these studies the source properties, X-ray interaction with matter together with geometrical and wave optics are needed, and these concepts are also presented here.
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| 5. |
- Grizolli, Walan, et al.
(författare)
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Use of astigmatic re-focusing at HP-XPS end-station
- 2013
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Ingår i: 11th International Conference on Synchrotron Radiation Instrumentation (SRI 2012). - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 425
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Konferensbidrag (refereegranskat)abstract
- In this paper we present the refocusing optics for the new high pressure photoelectron spectroscopy (HP-XPS) branch line at MAX-lab, based on a plane grating monochromator with vertically collimated beam. For the HP-XPS instrument, the required spot size is dictated by the small geometric acceptance of the HP-XPS electron energy analyzer. Whereas a pair of bendable mirrors in a KB configuration has some advantages as refocusing elements, we have studied whether similar performance can be achieved with a single non-bendable mirror. In this solution, however, the need for strong horizontal magnification results in a strong vertical magnification and into a very asymmetric image, the height being just a fraction of the width. We have studied through an analytical geometrical model and ray tracing simulations the use of astigmatism to increase the vertical beam size up to the geometric acceptance of the detector. As a result the vertical beam size at sample plane is mostly determined by the photon angular distribution and is not dependent on the exit slit aperture size. In addition the vertical beam size can be controlled by the grating c(ff) parameter, making possible to adjust the photon density and minimize sample damage by the radiation.
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| 6. |
- Urpelainen, Samuli, et al.
(författare)
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The SPECIES beamline at the MAX IV Laboratory : A facility for soft X-ray RIXS and APXPS
- 2017
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Ingår i: Journal of Synchrotron Radiation. - 1600-5775 .- 0909-0495. ; 24:1, s. 344-353
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Tidskriftsartikel (refereegranskat)abstract
- SPECIES is an undulator-based soft X-ray beamline that replaced the old I511 beamline at the MAX II storage ring. SPECIES is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (APXPS), near-edge X-ray absorption fine-structure (NEXAFS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) experiments. The beamline has two branches that use a common elliptically polarizing undulator and monochromator. The beam is switched between the two branches by changing the focusing optics after the monochromator. Both branches have separate exit slits, refocusing optics and dedicated permanent endstations. This allows very fast switching between two types of experiments and offers a unique combination of the surface-sensitive XPS and bulk-sensitive RIXS techniques both in UHV and at elevated ambient-pressure conditions on a single beamline. Another unique property of the beamline is that it reaches energies down to approximately 27 eV, which is not obtainable on other current APXPS beamlines. This allows, for instance, valence band studies under ambient-pressure conditions. In this article the main properties and performance of the beamline are presented, together with selected showcase experiments performed on the new setup.
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