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  • 1.
    Akan, Rabia
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Parfeniukas, Karolis
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Carmen
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Toprak, M. S.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reaction control of metal-assisted chemical etching for silicon-based zone plate nanostructures2018Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, nr 23, s. 12628-12634Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Metal-assisted chemical etching (MACE) reaction parameters were investigated for the fabrication of specially designed silicon-based X-ray zone plate nanostructures using a gold catalyst pattern and etching solutions composed of HF and H2O2. Etching depth, zone verticality and zone roughness were studied as a function of etching solution composition, temperature and processing time. Homogeneous, vertical etching with increasing depth is observed at increasing H2O2 concentrations and elevated processing temperatures, implying a balance in the hole injection and silica dissolution kinetics at the gold-silicon interface. The etching depth decreases and zone roughness increases at the highest investigated H2O2 concentration and temperature. Possible reasons for these observations are discussed based on reaction chemistry and zone plate design. Optimum MACE conditions are found at HFH2O2 concentrations of 4.7 M:0.68 M and room temperature with an etching rate of ≈0.7 μm min-1, which is about an order of magnitude higher than previous reports. Moreover, our results show that a grid catalyst design is important for successful fabrication of vertical high aspect ratio silicon nanostructures. 

  • 2. Beck, M.
    et al.
    Stiel, H.
    Leupold, D.
    Winter, B.
    Pop, D.
    Vogt, Ulrich
    Spitz, C.
    Evaluation of the energetic position of the lowest excited singlet state of beta-carotene by NEXAFS and photoemission spectroscopy2001Inngår i: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1506, nr 3, s. 260-267Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In carotenoids the lowest energetic optical transition belonging to the pi -electron system is forbidden by symmetry, therefore the energetic position of the S-1 (2(1)A(g)) level can hardly be assessed by optical spectroscopy. We introduce a novel experimental approach: For molecules with ir-electron systems the transition C1s --> 2p(pi*) from inner-atomic to the lowest unoccupied molecular orbital (LUMO) appears in X-ray absorption near edge spectra (NEXAFS) as an intense, sharp peak a few eV below the carbon K-edge. Whereas the peak position reflects the energy of the First excited singlet state in relation to the ionization potential of the molecule, intensity and width of the transition depend on hybridization and bonding partners of the selected atom. Complementary information can be obtained from ultraviolet photoelectron spectroscopy (UPS): At the low binding energy site of the spectrum a peak related to the highest occupied molecular orbital (HOMO) appears. We have measured NEXAFS and UPS of beta -carotene. Based on these measurements and quantum chemical calculations the HOMO and LUMO energies can be derived.

  • 3. Beck, M.
    et al.
    Vogt, Ulrich
    Will, I.
    Liero, A.
    Stiel, H.
    Sandner, W.
    Wilheim, T.
    A pulse-train laser driven XUV source for picosecond pump-probe experiments in the water window2001Inngår i: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 190, nr 06-jan, s. 317-326Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe the development of a table top soft X-ray source based on a laser produced plasma. The plasma is produced by a Nd:YLF pulse-train laser which delivers pulse trains of up to 400 pulses each of about 25 ps duration, Number and energy of the micropulses are fully computer controlled adjustable for an optimum interaction with a rotating solid target. Spectral, spatial and temporal characteristics of the X-ray emission from Mylar and copper targets have been studied. A calibrated back-illuminated CCD camera together with a slit grating spectrograph were utilized for the measurement of the absolute soft X-ray photon fluxes. The temporal measurements were performed using a streak camera while the plasma size was measured with a zone plate. An application of the system in a X-ray absorption experiment is shown, The advantages of the system in view of possible optical pump and soft X-ray probe experiments will be discussed.

  • 4.
    Bertilson, Michael C.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Takman, Per A. C.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Zone plate efficiency measurements with a laser-plasma source2007Inngår i: Advances in X-Ray/EUV Optics and Components II / [ed] Khounsary, AM; Morawe, C; Goto, S, 2007, Vol. 6705, s. F7050-F7050Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We demonstrate a compact instrument for rapid and accurate measurements of the absolute and local efficiency of soft x-ray zone plates in the water window [M. Bertilson, et al, Rev. Sci. Instrum 78, 026103 (2007)]. The arrangement is based on a new single-line lambda = 2.88 nm liquid-nitrogen-jet laser-plasma source. The versatility of the instrument enables micro and condenser zone plates with focal lengths in the range from similar to 200 mu m to similar to 100 mm to be measured. We demonstrate an accurate local efficiency map of a in-house fabricated micro zone plate. Furthermore, we show how this compact instrument allows rapid feedback to the fabrication process which is important for future improvements.

  • 5.
    Bertilson, Michael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olof
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Experimentell biomolekylär fysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High-resolution computed tomography with a compact soft x-ray microscope2009Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 17, nr 13, s. 11057-11065Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Computed tomography based on high-resolution soft x-ray microscopy utilizes the natural contrast for biological specimens provided by the water window (lambda = 2.4 - 4.4 nm) and the high resolving power of zone plate objectives. It is capable of revealing the 3D structure of biological specimens at sub-visible-microscopic resolution. To date, the technique has only been available at synchrotron-based microscopes, which limits the researchers access. In the present paper we demonstrate high-resolution soft x-ray tomography with a laboratory zone-plate-based soft x-ray microscope. The specimen, a diatom mounted on a glass capillary, was reconstructed from a tilt series of 53 images covering 180 using a filtered back projection algorithm. The resolution of the tomogram was estimated to a half period of 140 nm using a differential-phase-residual method. Cryo-fixation, increased source brightness and extended-depth-of-focus objectives are important for pushing the resolution of compact systems for biological samples.

  • 6.
    Bertilson, Michael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Numerical model for tomographic image formation in transmission x-ray microscopy2011Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, nr 12, s. 11578-11583Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a numerical image-formation model for investigating the influence of partial coherence, sample thickness and depth-of-focus on the accuracy of tomographic reconstructions in transmission x-ray microscopes. The model combines wave propagation through the object by finite difference techniques with Fourier methods. We include a ray-tracing model to analyse the origin of detrimental stray light in zone plate-based x-ray microscopes. These models allow optimization of x-ray microscopy systems for quantitative tomographic imaging of thick objects. Results show that both the depth-of-focus and the reconstructed local absorption coefficient are highly dependent on the degree of coherence of the optical system.

  • 7.
    Bertilson, Michael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wilhein, Thomas
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Compact high-resolution differential interference contrast soft x-ray microscopy2008Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 92, nr 064104Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate high-resolution x-ray differential interference contrast (DIC) in a compact soft x-ray microscope. Phase contrast imaging is enabled by the use of a diffractive optical element objective which is matched to the coherence conditions in the microscope setup. The performance of the diffractive optical element objective is evaluated in comparison with a normal zone plate by imaging of a nickel siemens star pattern and linear grating test objects. Images obtained with the DIC optic exhibit typical DIC enhancement in addition to the normal absorption contrast. Contrast transfer functions based on modulation measurements in the obtained images show that the DIC optic gives a significant increase in contrast without reducing the spatial resolution. The phase contrast operation mode now available for our compact soft x-ray microscope will be a useful tool for future studies of samples with low absorption contrast.

  • 8.
    Bertilson, Michael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Thieme, J.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    First application experiments with the Stockholm compact soft x-ray microscope2009Inngår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Most soft x-ray microscopes operating in the water window (lambda = 2.3 - 4.4 nm) rely on synchrotron radiation sources. In the future we believe scientists will use soft x-ray microscopes as one imaging tool among others in their own laboratory. For this purpose we have developed a full field soft x-ray microscope with a laser-plasma source compact enough to fit on an optical table. In this contribution we describe the current status of this microscope now featuring stable operation at lambda = 3.37 nm or lambda = 2.48 nm. In-house fabricated single element zone plates offering the possibility to perform phase contrast imaging have been implemented. We also report on the first application experiments for compact soft x-ray microscopy, including results from studies of clay minerals and colloids existing in nature and results from phase optics experiments. Planned upgrades of the microscope include increasing the source brightness, implementing more efficient condenser optics, and installing a cryo sample stage for tomography. These improvements will open up for further applications, especially in the field of biological imaging.

  • 9.
    Bertilson, Michael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Christakou, Athanasia E.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Laboratory soft-x-ray microscope for cryotomography of biological specimens2011Inngår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 36, nr 14, s. 2728-2730Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Soft-x-ray cryotomography allows quantitative and high-resolution three-dimensional imaging of intact unstained cells. To date, the method relies on synchrotron-radiation sources, which limits accessibility for researchers. Here we present a laboratory water-window microscope for cryotomography. It is based on a lambda = 2.48nm liquid-jet laser-plasma source, a normal-incidence multilayer condenser, a 30nm zone-plate objective, and a cryotilt sample holder. We demonstrate high-resolution imaging, as well as quantitative tomographic imaging, of frozen intact cells. The reconstructed tomogram of the intracellular local absorption coefficient shows details down to similar to 100nm.

  • 10.
    Bertilsson, Michael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Laboratory arrangement for soft x-ray zone-plate efficiency measurements2007Inngår i: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 78, nr 2, s. 026103-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate a laboratory-scale arrangement for rapid and accurate measurements of the absolute and local efficiency of soft x-ray micro zone plates in the water window. This in-house instrument is based on a single-line lambda=2.88 nm liquid-jet laser-plasma source. Measurements are performed by a simultaneous comparison of first diffraction-order photon flux with the flux in a calibrated reference signal. This arrangement eliminates existing source emission fluctuations. The performance of the method is demonstrated by the result from measurements of two similar to 55 mu m diameter nickel micro zone plates, showing a groove efficiency of 12.9%+/- 1.1% and 11.7%+/- 1.0%. Furthermore, we show that spatially resolved efficiency mapping is an effective tool for a detailed characterization of local zone plate properties. Thus, this laboratory-scale instrument allows rapid feedback to the fabrication process which is important for future improvements.

  • 11. Busch, S.
    et al.
    Schnurer, M.
    Kalashnikov, M.
    Schonnagel, H.
    Stiel, H.
    Nickles, P. V.
    Sandner, W.
    Ter-Avetisyan, S.
    Karpov, V.
    Vogt, Ulrich
    Ion acceleration with ultrafast lasers2003Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 82, nr 19, s. 3354-3356Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hot-electron confinement can build up fields capable of accelerating ions up to MeV energies when an ultrashort 35-fs laser pulse at similar to2x10(18) W/cm(2) interacts with a small spherical target. Singly charged ions with different masses have similar energies. A simple phenomenological model describes how ultrashort and less-energy-consumptive pulses drive ions to MeV energies. The energetic and spatial-emission characteristics of protons, deuterons and oxygen ions released from water and heavy-water droplets of similar to15 mum in size was determined for this interaction scenario.

  • 12.
    Chubarova, Elena
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Birch, Jens
    Department of Physics, Chemistry, and Biology, Linköping University.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Platinum zone plates for hard X-ray applications2011Inngår i: Microelectronic Engineering, ISSN 0167-9317, E-ISSN 1873-5568, Vol. 88, nr 10, s. 3123-3126Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe the fabrication and evaluation of platinum zone plates for 5–12 kV X-ray imaging and focusing. These nano-scale circular periodic structures are fabricated by filling an e-beam generated mold with Pt in an electroplating process. The plating recipe is described. The resulting zone plates, having outer zone widths of 100 and 50 nm, show good uniformity and high aspect ratio. Their diffraction efficiencies are 50–70% of the theoretical, as measured at the European Synchrotron Radiation Facility. Platinum shows promise to become an attractive alternative to present hard X-ray zone plate materials due to its nano-structuring properties and the potential for zone-plate operation at higher temperatures.

  • 13. Fernandez, Angel Rodriguez
    et al.
    Johansson, Ulf
    Carbone, Gerardina
    Bjorling, Alexander
    Kalbfleisch, Sebastian
    Stankevic, Comas
    Bring, Bjorn
    Mikkelsen, Anders
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    NanoMAX Beamline, a nanoprobe beamline for scattering and imaging at MAX IV2018Inngår i: ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES, ISSN 2053-2733, Vol. 74, s. E317-E318Artikkel i tidsskrift (Annet vitenskapelig)
  • 14. Freund, Oliver
    et al.
    Bartelt, Michael
    Mittelbach, Marc
    Montgomery, Matthew
    Vogt, Damian M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Seume, Joerg R.
    Impact of the Flow on an Acoustic Excitation System for Aeroelastic Studies2013Inngår i: Journal of turbomachinery, ISSN 0889-504X, E-ISSN 1528-8900, Vol. 135, nr 3, s. 031033-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The flow in turbomachines is highly unsteady. Effects like vortices, flow separation, and shocks are an inevitable part of the turbomachinery flow. Furthermore, high blade aspect ratios, aerodynamically highly loaded and thin profiles increase the blade sensitivity to vibrations. According to the importance of aeroelasticity in turbomachines, new strategies for experimental studies in rotating machines must be developed. A basic requirement for aeroelastic research in rotating machines is to be able to excite the rotor blades in a defined manner. Approaches for active blade excitation in running machines may be piezoelectric elements, magnetism, or acoustics. Contact-free excitation methods are preferred, since additional mistuning is brought into the investigated system otherwise. A very promising method for aeroelastic research is the noncontact acoustic excitation method. In this paper, investigations on the influence of an annular cascade flow on the blade vibration, excited by an acoustic excitation system, are presented for the first time. These investigations are carried out at the Aeroelastic Test Rig of the Royal Institute of Technology in Stockholm. By varying the excitation angle, the outlet Mach number, and the relative position of the excited blade to the excitation system, the influence of the flow on the acoustic excitation is quantified. The results show that there is a strong dependency of the excited vibration amplitude on the excitation angle if the outlet Mach number is increased, which implies that preferable excitation directions exist. Furthermore, it is shown that a benefit up to 23% in terms of excited vibration amplitude can be reached if the flow velocity is raised.

  • 15. Fruke, R.
    et al.
    Wilhein, T.
    Wieland, M.
    Vogt, Ulrich
    Imaging of a laser plasma source at 13 nm wavelength approaching submicrometer resolution2003Inngår i: Journal de Physique IV: Colloque, ISSN 1155-4339, E-ISSN 1764-7177, Vol. 104, s. 153-156Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Radiation in the extreme ultraviolet (EUV) spectral range is of interest for lithography and microscopy. Laser produced plasmas are sources for this kind of radiation. For successful usage it is necessary to study the source properties like size, stability and emitted spectra. For the spatial characterization of such a source a beamline was built up. The source was imaged at 13, 15 and 17 nm wavelength and at different laser energies with a resolution of better than 2 mum. As target material ethanol was used which was excited by a frequency-doubled Nd:YAG laser (lambda=532 nm; 3 ns, 30 Hz). The source was mapped with a zone plate (KZP5: d=2500 mum, Deltar(n)=0,523 mum). With a magnification of 61 the images were taken with a thinned back-illuminated CCD. Additionally a periodic structure was mapped with micrometer resolution, too.

  • 16.
    Hertz, Hans
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Chubarova, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    von Hofsten, Olof
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Vogt, Ulrich
    Laboratory Water-Window X-Ray Microscopy2009Inngår i: 2009 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS: VOLS 1 AND 2, 2009, s. 48-48Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We review recent progress in laboratory water-window microscopy including 250 W/0.8 ns/2 kHz laser-plasma liquid-jet sources, 13-nm zone width diffractive optics, diffractive optical elements for phase-contrast microscopy, <25-nm resolution microscopy using compound zone plates, tomography and applications in soil science.

  • 17.
    Hertz, Hans M.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael C.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Chubarova, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hemberg, Oscar
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hofsten, Olov Von
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Ulf
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Otendal, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Skoglund, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Tuohimaa, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Laboratory X-ray micro- and nano-imaging2009Inngår i: Frontiers in Optics (FiO) 2009, Optical Society of America, 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We summarize recent progress in laboratory x-ray imaging systems based on compact high-brightness liquid-jet sources, including <25 nm soft x-ray zone-plate microscopy and <10 μm (lens-free) hard x-ray phase-contrast imaging.

  • 18.
    Hertz, Hans M.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Chubarova, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Ewald, Johannes
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Gleber, S-C
    Hemberg, Oscar
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Henriksson, M.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Mudry, Emeric
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Otendal, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Schlie, Moritz Gustav
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Skoglund, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Thieme, J.
    Sedlmair, J.
    Tjörnhammar, Richard
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Tuohimaa, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vita, M.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Laboratory x-ray micro imaging: Sources, optics, systems and applications2009Inngår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We summarize the recent progress in laboratory-scale soft and hard x-ray micro imaging in Stockholm. Our soft x-ray work is based on liquid-jet laser-plasma sources which are combined with diffractive and multilayer optics to form laboratory x-ray microscopes. In the hard x-ray regime the imaging is based on a liquid-metal-jet electron-impact source which provides the necessary coherence to allow phase-contrast imaging with high fidelity.

  • 19.
    Hertz, Hans
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia Antonia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Martz, Dale
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Selin, Mårten
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Christakou, Athanasia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Jerlström-Hultqvist, J
    Svärd, S
    Laboratory cryo soft X-ray microscopy2012Inngår i: Journal of Structural Biology, ISSN 1047-8477, E-ISSN 1095-8657, Vol. 177, nr 2, s. 267-272Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lens-based water-window X-ray microscopy allows two- and three-dimensional (2D and 3D) imaging of intact unstained cells in their near-native state with unprecedented contrast and resolution. Cryofixation is essential to avoid radiation damage to the sample. Present cryo X-ray microscopes rely on synchrotron radiation sources, thereby limiting the accessibility for a wider community of biologists. In the present paper we demonstrate water-window cryo X-ray microscopy with a laboratory-source-based arrangement. The microscope relies on a lambda = 2.48-nm liquid-jet high-brightness laser-plasma source, normal-incidence multilayer condenser optics, 30-nm zone-plate optics, and a cryo sample chamber. We demonstrate 2D imaging of test patterns, and intact unstained yeast, protozoan parasites and mammalian cells. Overview 3D information is obtained by stereo imaging while complete 3D microscopy is provided by full tomographic reconstruction. The laboratory microscope image quality approaches that of the synchrotron microscopes, but with longer exposure times. The experimental image quality is analyzed from a numerical wave-propagation model of the imaging system and a path to reach synchrotron-like exposure times in laboratory microscopy is outlined.

  • 20.
    Holmberg, Anders
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Chubarova, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Selin, Mårten
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Larsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Skoglund Lindberg, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundstrom, Ulf
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Towards 10-nm Soft X-Ray Zone Plate Fabrication2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper the latest efforts to improve our nanofabrication process for soft x‐ray zone plates is presented. The resolving power, which is proportional to the smallest outermost zone width of the zone plate, is increased by introducing cold development of the electron beam resist that is used for the patterning. With this process we have fabricated Ni zone plates with 13‐nm outermost zone and shown potential for making 11‐nm half‐pitch lines in the electron beam resist. Maintaining the diffraction efficiency of the zone plate is a great concern when the outermost zone width is decreased. To resolve this problem we have developed the so‐called Ni‐Ge zone plate in which the zone plate is build up by Ni and Ge, resulting in an increase of the diffraction efficiency. In a proof‐of‐principle experiment with 25‐nm Ni‐Ge zone plates, we have shown a doubling of the diffraction efficiency. When combined with cold development, the Ni‐Ge process has been shown to work down to 16‐nm half‐pitch. It is plausible that further refinement of the process will make it possible to go to 10‐nm outermost zone widths.

  • 21. Hoppe, R.
    et al.
    Meier, V.
    Patommel, J.
    Seiboth, F.
    Lee, H. J.
    Nagler, B.
    Galtier, E. C.
    Arnold, B.
    Zastrau, U.
    Hastings, J.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Schroer, C. G.
    Schropp, A.
    Full characterization of a focused wavefield with sub 100 nm resolution2013Inngår i: Advances In X-Ray Free-Electron Lasers II: Instrumentation, SPIE - International Society for Optical Engineering, 2013, s. 87780G-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A hard x-ray free-electron laser (XFEL) provides an x-ray source with an extraordinary high peak-brilliance, a time structure with extremely short pulses and with a large degree of coherence, opening the door to new scientific fields. Many XFEL experiments require the x-ray beam to be focused to nanometer dimensions or, at least, benefit from such a focused beam. A detailed knowledge about the illuminating beam helps to interpret the measurements or is even inevitable to make full use of the focused beam. In this paper we report on focusing an XFEL beam to a transverse size of 125nm and how we applied ptychographic imaging to measure the complex wavefield in the focal plane in terms of phase and amplitude. Propagating the wavefield back and forth we are able to reconstruct the full caustic of the beam, revealing aberrations of the nano-focusing optic. By this method we not only obtain the averaged illumination but also the wavefield of individual XFEL pulses.

  • 22.
    Jansson, Per
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ultich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Liquid-nitrogen-jet laser-plasma source for compact soft x-ray microscopy2005Inngår i: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 76, nr 4, s. 043503-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe a liquid-nitrogen-jet laser-plasma source with sufficient brightness, uniformity, stability, and reliability to be suitable for compact water-window soft x-ray transmission microscopy. A cooled capillary nozzle arrangement allows long-term operation and avoids previously reported jet instabilities. The source is quantitatively characterized by calibrated slit-grating spectroscopy and zone-plate imaging. The absolute photon number in the major spectral lines (lambda=2.48 nm and lambda=2.88 nm) is 1.0x10(12) photons/(pulsexsrxline). The source diameter is similar to 20 mu m (full width at half maximum) and the spatial stability is better than +/- 2 mu m. Within an area with uniformity of 20%, the average source brightness is 4x10(8) photons/(pulsexsrx mu m(2)xline), which allows operation of a compact soft x-ray transmission microscope with exposure times of a few minutes.

  • 23. Johansson, Ulf
    et al.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Mikkelsen, Anders
    NanoMAX: a hard x-ray nanoprobe beamline at MAX IV2013Inngår i: SPIE Optical Engineering+ Applications, 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We describe the design of the NanoMAX beamline to be built among the first phase beamlines of the MAX IV facility inLund, Sweden. NanoMAX will be a hard X-ray imaging beamline providing down to 10 nm in direct spatial resolution,enabling investigations of very small heterogeneous samples exploring methods of diffraction, scattering, absorption,phase contrast and fluorescence. The beamline will have two experimental stations using Fresnel zone plates andKirkpatrick-Baez mirror optics for beam focusing, respectively. This paper focuses on the optical design of the beamlineexcluding the experimental stations but also describes general ideas about the endstations and the nano-focusing optics tobe used. The NanoMAX beamline is planned to be operational late 2016.

  • 24. Kaulich, B
    et al.
    Bacescu, D
    Susini, J
    David, C
    Di Fabrizio, E
    Morrison, G R
    Charalambous, P
    Thieme, J
    Wilhein, T
    Kovac, J
    Cocco, D
    Salome, M
    Dhez, O
    Weitkamp, T
    Cabrini, S
    Cojoc, D
    Gianoncelli, A
    Vogt, Ulrich
    Fachhochschule Koblenz, RheinAhrCampus Remagen, Suedallee 2, D53424 Remagen, Germany.
    Podnar, M
    Zangrando, M
    Zacchigna, M
    Kiskinova, M
    TwinMic : A European Twin X-ray Microscopy Station Commissioned at ELETTRA2006Inngår i: Proc. 8th Int. Conf. X-ray Microscopy / [ed] S. Aoki, Y. Kagoshima, Y. Suzuki, 2006, s. 22-25Konferansepaper (Fagfellevurdert)
  • 25. Kaulich, B.
    et al.
    Susini, J.
    David, C.
    Fabrizio, E. Di
    Morrison, G. R.
    Thieme, J.
    Wilhein, T.
    Kovac, J.
    Bacescu, D.
    Salome, M.
    Dhez, O.
    Weitkamp, T.
    Cabrini, S.
    Gosperini, A.
    Charalambous, P.
    Vogt, Ulrich
    University of Applied Sciences Koblenz.
    Podnar, M.
    Kiskinova, M.
    TwinMic - Combined scanning and full-field imaging microscopy with novel contrast mechanisms2003Inngår i: Synchrotron Radiation News, Vol. 16, s. 49-52Artikkel i tidsskrift (Fagfellevurdert)
  • 26. Korn, G.
    et al.
    Thoss, A.
    Stiel, H.
    Vogt, Ulrich
    Richardson, M.
    Elsaesser, T.
    Faubel, M.
    Ultrashort 1-kHz laser plasma hard x-ray source2002Inngår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 27, nr 10, s. 866-868Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We achieved a continuous, stable, ultrashort pulse hard x-ray point source by focusing 1.8-W, 1-kHz, 50-fs laser pulses onto a novel, 30-mum-diameter, high-velocity, liquid-metal gallium jet. This target geometry avoids most of the debris problems of solid targets and provides nearly 4pi illumination. Photon fluxes of 5 X 10(8) photons/s are generated in a two-component spectrum consisting of a broad continuum from 4 to 14 keV and strong K-alpha and K-beta emission lines at 9.25 and 10.26 keV. This source will find wide use in time-resolved x-ray diffraction studies and other applications.

  • 27. Legall, H.
    et al.
    Blobel, G.
    Stiel, H.
    Sandner, W.
    Seim, C.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Martz, Dale H.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Selin, Mårten
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Esser, D.
    Sipma, H.
    Luttmann, J.
    Höfffer, M.
    Hoffmann, H. D.
    Yulin, S.
    Feigl, T.
    Rehbein, S.
    Guttmann, P.
    Schneider, G.
    Wiesemann, U.
    Wirtz, M.
    Diete, W.
    Compact X-ray microscope for the water window based on a high brightness laser plasma source2012Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 20, nr 16, s. 18362-18369Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a laser plasma based x-ray microscope for the water window employing a high-average power laser system for plasma generation. At 90 W laser power a brightness of 7.4 x 10(11) photons/(s x sr x mu m(2)) was measured for the nitrogen Ly alpha line emission at 2.478 nm. Using a multilayer condenser mirror with 0.3 % reflectivity 10(6) photons/(mu m(2) x s) were obtained in the object plane. Microscopy performed at a laser power of 60 W resolves 40 nm lines with an exposure time of 60 s. The exposure time can be further reduced to 20 s by the use of new multilayer condenser optics and operating the laser at its full power of 130 W.

  • 28. Legall, H.
    et al.
    Stiel, H.
    Vogt, Ulrich
    Schonnagel, H.
    Nickles, P. V.
    Tummler, J.
    Scholz, F.
    Scholze, F.
    Spatial and spectral characterization of a laser produced plasma source for extreme ultraviolet metrology2004Inngår i: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 75, nr 11, s. 4981-4988Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a laser produced plasma (LPP) source optimized for metrology and the results of its radiometric characterization. The presented (LPP) source can be used for reflectometry and spectroscopy in the soft x-ray range. For these applications, stable operation with high spectral photon yields high reliability in continuous operation and, to reach high spectral resolution, a small source size and high source point stability is necessary. For the characterization of the source, special instruments have been designed and calibrated using the soft x-ray radiometry beamline of the Physikalisch-Technische-Bundesanstalt at BESSY. These instruments are an imaging spectrometer, a double multilayer tool for in-band power measurements, a transmission slit grating spectrograph, and a pinhole camera. From the measurements a source size of 30 mumx55 mum (2sigma, horizontal by vertical) and a stability of better than 5 mum horizontally and 9 mum vertically were obtained. The source provides a flat continuous emission in the extreme ultraviolet (EUV) range around 13.4 nm and a spectral photon flux of up to 1*10(14)/(s sr 0.1 nm) at a pump laser pulse energy of 650 mJ. The shot-to-shot stability of the source is about 5% (1sigma) for laser pulse energies above 200 mJ. It is shown that an Au-LPP source provides spectrally reproducible emission with sufficient power at low debris conditions for the operation of a laboratory based EUV reflectometer and for spectroscopy.

  • 29.
    Lindblom, Magnus
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Tuohimaa, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wilhein, Thomas
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High-resolution differential-interference-contrast x-ray zone plates: Design and Fabrication2007Inngår i: Spectrochimica Acta Part B - Atomic Spectroscopy, ISSN 0584-8547, E-ISSN 1873-3565, Vol. 62, nr 6-7, s. 539-543Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Differential interference contrast is a potentially powerful technique for contrast enhancement in soft X-ray microscopy. We describe the design and fabrication of single-element diffractive optical elements suitable as objectives for high-resolution differential interference contrast microscopy in the water-window spectral range. A one-dimensional pattern calculation followed by an extension to two dimensions results in a pattern resolution of 1 nm, which is well below fabrication accuracy. The same fabrication process as for normal zone plates is applicable, but special care must be taken when converting the calculated pattern to a code for e-beam lithography.

  • 30.
    Martz, Dale H.
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Selin, Mårten
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Fogelqvist, Emelie
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Legall, H.
    Blobel, G.
    Seim, C.
    Stiel, H.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High average brightness water window source for short-exposure cryomicroscopy2012Inngår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 37, nr 21, s. 4425-4427Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Laboratory water window cryomicroscopy has recently demonstrated similar image quality as synchrotron-based microscopy but still with much longer exposure times, prohibiting the spread to a wider scientific community. Here we demonstrate high-resolution laboratory water window imaging of cryofrozen cells with 10 s range exposure times. The major improvement is the operation of a lambda = 2.48 nm, 2 kHz liquid nitrogen jet laser plasma source with high spatial and temporal stability at high average brightness >1.5 x 10(12) ph/(s x sr x mu m(2) x line), i.e., close to that of early synchrotrons. Thus, this source enables not only biological x-ray microscopy in the home laboratory but potentially other applications previously only accessible at synchrotron facilities.

  • 31.
    Nilsson, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Anders, Holmberg
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Sinn, H.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Computer simulation of heat transfer in zone plate optics exposed to X-ray FEL radiation2011Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8077Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Zone plates are circular diffraction gratings that can provide diffraction-limited nano-focusing of x-ray radiation. When designing zone plates for X-ray Free Electron Laser (XFEL) sources special attention has to be made concerning the high intensity of the sources. Absorption of x-rays in the zone material can lead to significant temperature increases in a single pulse and potentially destroy the zone plate. The zone plate might also be damaged as a result of temperature build up and/or temperature fluctuations on longer time scales. In this work we simulate the heat transfer in a zone plate on a substrate as it is exposed to XFEL radiation. This is done in a Finite Element Method model where each new x-ray pulse is treated as an instantaneous heat source and the temperature evolution between pulses is calculated by solving the heat equation. We use this model to simulate different zone plate and substrate designs and source parameters. Results for both the 8 keV source at LCLS and the 12.4 keV source at the European XFEL are presented. We simulate zone plates made of high Z metals such as gold, tungsten and iridium as well as zone plates made of low Z materials such as diamond. In the case of metal zone plates we investigate the influence of substrate material by comparing silicon and diamond substrates. We also study the effect of different cooling temperatures and cooling schemes. The results give valuable indications on the temperature behavior to expect and can serve as a basis for future experimental investigations of zone plates exposed to XFEL radiation.

  • 32.
    Nilsson, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Sinn, H.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Simulation of heat transfer in zone plate optics irradiated by X-ray free electron laser radiation2010Inngår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 621, nr 1-3, s. 620-626Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Zone plates are high quality optics that have the potential to provide diffraction-limited nano-focusing of hard X-ray free electron laser radiation. The present publication investigates theoretically the temperature behavior of metal zone plates on a diamond substrate irradiated by 0.1 nm X-rays from the European X-ray Free Electron Laser. The heat transfer in the optic is simulated by solving the transient heat equation with the finite element method. Two different zone plate designs are considered, one small zone plate placed in the direct beam and one larger zone plate after the monochromator. The main result is that for all investigated cases the maximum temperature in the metal zone plate layer is at least a factor 2 below the melting point of the respective material, proving the efficiency of the proposed cooling scheme. However, zone plates in the direct beam experience large and rapid temperature fluctuations of several hundred Kelvin that might prove fatal to the optic. The situation is different for optics behind the monochromator with fluctuations in the 20 K range and maximum temperatures well below room temperature. The simulation results give valuable indications on the temperature behavior to be expected and are a basis for future experimental heat transfer and mechanical stability investigations of fabricated nanostructures.

  • 33.
    Nilsson, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Sinn, H.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Zone Plates for Hard X-Ray FEL Radiation2011Inngår i: 10TH INTERNATIONAL CONFERENCE ON X-RAY MICROSCOPY / [ed] McNulty, I; Eyberger, C; Lai, B, American Institute of Physics (AIP), 2011, Vol. 1365, s. 120-123Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We investigated theoretically the use of zone plates for the focusing of the European X-ray Free Electron Laser (XFEL). In a finite-element simulation the heat load on zone plates placed in the high intensity x-ray beam was simulated for four different zone plate materials: gold, iridium, tungsten, and CVD diamond. The main result of the calculations is that all zone plates remain below the melting temperature throughout a full XFEL pulse train of 3000 pulses. However, if the zone plate is placed in the direct beam it will experience large and rapid temperature fluctuations on the order of 300 K. The situation is relaxed if the optic is placed behind a monochromator and the fluctuations are reduced to around 20 K. Besides heat load, the maximization of the total efficiency of the complete optical system is an important issue. We calculated the efficiency of different zone plates and monochromator systems and found that the final beam size of the XFEL in combination with its monochromaticity will be important parameters.

  • 34.
    Nilsson, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Schropp, A.
    Patommel, J.
    Hoppe, R.
    Seiboth, F.
    Meier, V.
    Schroer, C. G.
    Galtier, E.
    Nagler, B.
    Lee, H. J.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Ronchi test for characterization of nanofocusing optics at a hard x-ray free-electron laser2012Inngår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 37, nr 24, s. 5046-5048Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate the use of the classical Ronchi test to characterize aberrations in focusing optics at a hard x-ray free-electron laser. A grating is placed close to the focus and the interference between the different orders after the grating is observed in the far field. Any aberrations in the beam or the optics will distort the interference fringes. The methodis simple to implement and can provide single-shot information about the focusing quality. We used the Ronchi test to measure the aberrations in a nanofocusing Fresnel zone plate at the Linac Coherent Light Source at 8.194 keV.

  • 35.
    Nilsson, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Sinn, H.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Thermal stability of tungsten zone plates for focusing hard x-ray free-electron laser radiation2012Inngår i: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 14, s. 043010-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Diffractive Fresnel zone plates made of tungsten show great promise for focusing hard x-ray free-electron laser (XFEL) radiation to very small spot sizes. However, they have to withstand the high-intensity pulses of the beam without being damaged. This might be problematic since each XFEL pulse will create a significant temperature increase in the zone plate nanostructures and it is therefore crucial that the optics are thermally stable, even for a large number of pulses. Here we have studied the thermal stability of tungsten zone-platelike nanostructures on diamond substrates using a pulsed Nd:YAG laser which creates temperature profiles similar to those expected from XFEL pulses. We found that the structures remained intact up to a laser fluence of 100 mJ cm(-2), corresponding to a 6 keV x-ray fluence of 590 mJ cm-2, which is above typical fluence levels in an unfocused XFEL beam. We have also performed an initial damage experiment at the LCLS hard XFEL facility at SLAC National Accelerator Laboratory, where a tungsten zone plate on a diamond substrate was exposed to 105 pulses of 6 keV x-rays with a pulse fluence of 350 mJ cm-2 without any damage occurring.

  • 36.
    Otendal, Mikael
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Touhimaa, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    A 9 keV electron-impact liquid-gallium-jet x-ray source2008Inngår i: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 79, nr 1, s. 016102-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate a high-brightness compact 9 keV electron-impact microfocus x-ray source based on a liquid-gallium-jet anode. A similar to 30 W, 50 kV electron gun is focused onto the similar to 20 m/s, 30 mu m diameter liquid-gallium-jet anode to produce an similar to 10 mu m full width at half maximum x-ray spot. The peak spectral brightness is >2 x 10(10) photons/(s mm(2) mrad(2) x 0.1% BW). Calculation and experiments show potential for increasing this brightness by approximately three orders of magnitude, making the source suitable for laboratory-scale x-ray crystallography and hard x-ray microscopy.

  • 37.
    Parfeniukas, Karolis
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Giakoumidis, Stylianos
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Akan, Rabia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High-aspect ratio zone plate fabrication for hard x-ray nanoimaging2017Inngår i: Advances in X-Ray/EUV Optics and Components XII / [ed] Morawe, C Khounsary, AM Goto, S, SPIE - International Society for Optical Engineering, 2017, Vol. 10386, artikkel-id UNSP 103860SKonferansepaper (Fagfellevurdert)
    Abstract [en]

    We present our results in fabricating Fresnel zone plate optics for the NanoMAX beamline at the fourth-generation synchrotron radiation facility MAX IV, to be used in the energy range of 6-10 keV. The results and challenges of tungsten nanofabrication are discussed, and an alternative approach using metal-assisted chemical etching (MACE) of silicon is showcased. We successfully manufactured diffraction-limited zone plates in tungsten with 30 nm outermost zone width and an aspect ratio of 21:1. These optics were used for nanoimaging experiments at NanoMAX. However, we found it challenging to further improve resolution and diffraction efficiency using tungsten. High efficiency is desirable to fully utilize the advantage of increased coherence on the optics at MAX IV. Therefore, we started to investigate MACE of silicon for the nanofabrication of high-resolution and high-efficiency zone plates. The first type of structures we propose use the silicon directly as the phase-shifting material. We have achieved 6 mu m deep dense vertical structures with 100 nm linewidth. The second type of optics use iridium as the phase material. The structures in the silicon substrate act as a mold for iridium coating via atomic layer deposition (ALD). A semi-dense pattern is used with line-to-space ratio of 1:3 for a so-called frequency-doubled zone plate. This way, it is possible to produce smaller structures with the tradeoff of the additional ALD step. We have fabricated 45 nm-wide and 3.6 mu m-tall silicon/iridium structures.

  • 38.
    Parfeniukas, Karolis
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Giakoumidis, Stylianos
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Seiboth, F.
    Wittwer, F.
    Schroer, C. G.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Improved tungsten nanofabrication for hard X-ray zone plates2016Inngår i: Microelectronic Engineering, ISSN 0167-9317, E-ISSN 1873-5568, Vol. 152, s. 6-9Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present an improved nanofabrication method of high aspect ratio tungsten structures for use in high efficiency nanofocusing hard X-ray zone plates. A ZEP 7000 electron beam resist layer used for patterning is cured by a second, much larger electron dose after development. The curing step improves pattern transfer fidelity into a chromium hard mask by reactive ion etching using Cl2/O2 chemistry. The pattern can then be transferred into an underlying tungsten layer by another reactive ion etching step using SF6/O2. A 630 nm-thick tungsten zone plate with smallest line width of 30 nm was fabricated using this method and characterized. At 8.2 keV photon energy the device showed an efficiency of 2.2% with a focal spot size at the diffraction limit, measured at Diamond Light Source I-13-1 beamline.

  • 39. Schaefer, D.
    et al.
    Nisius, T.
    Frueke, R.
    Rausch, S.
    Wieland, M.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wilhein, T.
    Compact X-ray microscopes for EUV- and soft X-radiation with spectral imaging capabilities2006Inngår i: Advances in X-Ray/EUV Optics, Components, and Applications / [ed] Khounsary, AM; Morawe, C, 2006, Vol. 6317, s. 31704-31704Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We report on a compact full-field transmission microscope (CTXM) and a scanning transmission microscope (CST'XM) developed for imaging at laboratory scale X-ray sources. The microscopes are based on zone plates for imaging in the EUV and water window region (wavelength 2.3 nm to 4.4 mn). The radiation for the full-field microscope is generated by focusing short laser pulses with an energy of 100 mJ on a 20 gm cryogenic liquid nitrogen jet. A condenser zone plate in conjunction with an aperture is used to provide monochromatic sample illumination. This allows for easy wavelength selection within the N-2,-Emission spectrum. Thus, the presented setup offers the possibility of spectral imaging. A micro zone plate generates a magnified image detected by a back illuminated TE-cooled CCD camera (1,340 x 1,300 pixel). The actual configuration provides magnifications up to 1,000x at exposure times in a range of a few ten minutes with sub-100 nm resolution. Our compact scanning microscope (CSTXM) operates with a zone plate, focusing the radiation onto a sample which is placed on a piezo driven xy-stage with 1 nm lateral resolution. Using high-harmonic radiation at 13 nm wavelength sub-micron resolution is achieved. With light at 17 nm wavelength originating from the O-VI emission line of a laser plasma source based on an ethanol jet, 500 nm structures were imaged in less than 20 minutes resulting in an 100 x 40 pixel image.

  • 40. Schnurer, M.
    et al.
    Ter-Avetisyan, S.
    Stiel, H.
    Vogt, Ulrich
    Radloff, W.
    Kalashnikov, M.
    Sandner, W.
    Nickles, P. V.
    Influence of laser pulse width on absolute EUV-yield from Xe-clusters2001Inngår i: European Physical Journal D: Atomic, Molecular and Optical Physics, ISSN 1434-6060, E-ISSN 1434-6079, Vol. 14, nr 3, s. 331-335Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Using 50 fs (similar to 2 x 10(18) W/cm(2)) and 2 ps (similar to 5 x 10(16) W/cm(2)) pulses from a Ti:Sa multi-TW laser at 800 nm wavelength large Xe-clusters (10(5)...10(6) atoms per cluster) have been excited. Absolute yield measurements of EUV-emission in a wavelength range between 10 nm and 15 nm in combination with cluster target variation were carried out. The ps-laser pulse has resulted in about 30% enhanced and spatially more uniform EUV-emission compared to fs-laser excitation. Circularly polarized laser light instead of linear polarization results in enhanced emission which is probably caused by electrons gaining higher energies by the polarization dependent optical field ionization process. An absolute emission efficiency at 13.4 nm of up to 0.8% in 2 pi sr and 2.2% bandwidth has been obtained.

  • 41. Schroer, Christian G
    et al.
    Brack, Florian-Emanuel
    Brendler, Roman
    Hönig, Susanne
    Hoppe, Robert
    Patommel, Jens
    Ritter, Stephan
    Scholz, Maria
    Schropp, Andreas
    Seiboth, Frank
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinhardt, Juliane
    Falkenberg, Gerald
    Hard x-ray nanofocusing with refractive x-ray optics: full beam characterization by ptychographic imaging2013Inngår i: Proceedings of SPIE, 2013, s. 884807-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hard x-ray scanning microscopy relies on small and intensive nanobeams. Refractive x-ray lenses are well suited to generate hard x-ray beams with lateral dimensions of 100 nm and below. The diffraction limited beam size of refractive x-ray lenses mainly depends on the focal length and the attenuation inside the lens material. The numerical aperture of refractive lenses scales with the inverse square root of the focal length until it reaches the critical angle of total reflection. We have used nanofocusing refractive x-ray lenses made of silicon to focus hard x-rays at 8 and 20 keV to (sub-)100 nm dimensions. Using ptychographic scanning coherent diffraction imaging we have characterized these nanobeams with high accuracy and sensitivity, measuring the full complex wave field in the focus. This gives access to the full caustic and aberrations of the x-ray optics. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  • 42. Schropp, Andreas
    et al.
    Hoppe, Robert
    Meier, Vivienne
    Patommel, Jens
    Seiboth, Frank
    Lee, Hae Ja
    Nagler, Bob
    Galtier, Eric C.
    Arnold, Brice
    Zastrau, Ulf
    Hastings, Jerome B.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Schroer, Christian G.
    Full spatial characterization of a nanofocused x-ray free-electron laser beam by ptychographic imaging2013Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 3, s. 1633-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The emergence of hard X-ray free electron lasers (XFELs) enables new insights into many fields of science. These new sources provide short, highly intense, and coherent X-ray pulses. In a variety of scientific applications these pulses need to be strongly focused. In this article, we demonstrate focusing of hard X-ray FEL pulses to 125 nmusing refractive x-ray optics. For a quantitative analysis of most experiments, the wave field or at least the intensity distribution illuminating the sample is needed. We report on the full characterization of a nanofocused XFEL beam by ptychographic imaging, giving access to the complex wave field in the nanofocus. From these data, we obtain the full caustic of the beam, identify the aberrations of the optic, and determine the wave field for individual pulses. This information is for example crucial for high-resolution imaging, creating matter in extreme conditions, and nonlinear x-ray optics.

  • 43. Schropp, Andreas
    et al.
    Hoppe, Robert
    Patommel, Jens
    Seiboth, Frank
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lee, Hae Ja
    Nagler, Bob
    Galtier, Eric C
    Zastrau, Ulf
    Arnold, Brice
    Heimann, Philip
    Hastings, Jerome B
    Schroer, Christian G
    Scanning coherent x-ray microscopy as a tool for XFEL nanobeam characterization2013Inngår i: Proceedings of SPIE: The International Society for Optical Engineering, 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    During the last years, scanning coherent x-ray microscopy, also called ptychography, has revolutionized nanobeam characterization at third generation x-ray sources. The method yields the complete information on the complex valued, nanofocused wave field with high spatial resolution. In an experiment carried out at the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS) we successfully applied the method to an attenuated nanofocused XFEL beam with a size of 180(h) × 150(v) nm2 (FWHM) in horizontal (h) and vertical direction (v), respectively. It was created by a set of 20 beryllium compound refractive lenses (Be-CRLs). By using a fast detector (CSPAD) to record the diffraction patterns and a fast implementation of the phase retrieval code running on a graphics processing unit (GPU), the applicability of the method as a real-time XFEL nanobeam diagnostic is highlighted.

  • 44. Seiboth, F.
    et al.
    Schropp, A.
    Hoppe, R.
    Meier, V.
    Patommel, J.
    Lee, H. J.
    Nagler, B.
    Galtier, E. C.
    Arnold, B.
    Zastrau, U.
    Hastings, J. B.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Schroer, C. G.
    Focusing XFEL SASE pulses by rotationally parabolic refractive x-ray lenses2014Inngår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 499, nr 1, s. 012004-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Using rotationally parabolic refractive x-ray lenses made of beryllium, we focus hard x-ray free-electron laser pulses of the Linac Coherent Light Source (LCLS) down to a spot size in the 100 nm range. We demonstrated efficient nanofocusing and characterized the nanofocused wave field by ptychographic imaging [A. Schropp, et al., Sci. Rep. 3, 1633 (2013)] in the case of monochromatic LCLS pulses produced by a crystal monochromator that decreases the LCLS bandwidth down to ΔE/E 1.4 · 10-4. The full spectrum of LCLS pulses generated by self-amplified spontaneous emission (SASE), however, fluctuates and has a typical bandwidth of a few per mille (ΔE/E 2 · 10-3). Due to the dispersion in the lens material, a polychromatic nanobeam generated by refractive x-ray lenses is affected by chromatic aberration. After reviewing the chromaticity of refractive x-ray lenses, we discuss the influence of increased bandwidth on the quality of a nanofocused SASE pulse.

  • 45. Seiboth, Frank
    et al.
    Schropp, Andreas
    Scholz, Maria
    Wittwer, Felix
    Roedel, Christian
    Wuensche, Martin
    Ullsperger, Tobias
    Nolte, Stefan
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Parfeniukas, Karolis
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Giakoumidis, Stylianos
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wagner, Ulrich
    Rau, Christoph
    Boesenberg, Ulrike
    Garrevoet, Jan
    Falkenberg, Gerald
    Galtier, Eric C.
    Lee, Hae Ja
    Nagler, Bob
    Schroer, Christian G.
    Aberration Correction for Hard X-ray Focusing at the Nanoscale2017Inngår i: Advances in X-Ray/EUV Optics and Components XII / [ed] Morawe, C Khounsary, AM Goto, S, SPIE - International Society for Optical Engineering, 2017, artikkel-id UNSP 103860AKonferansepaper (Fagfellevurdert)
    Abstract [en]

    We developed a corrective phase plate that enables the correction of residual aberration in reflective, diffractive, and refractive X-ray optics. The principle is demonstrated on a stack of beryllium compound refractive lenses with a numerical aperture of 0.49 x 10(-3) at three different synchrotron radiation and x-ray free-electron laser facilities. By introducing this phase plate into the beam path, we were able to correct the spherical aberration of the optical system and improve the Strehl ratio of the optics from 0.29(7) to 0.87(5), creating a diffraction-limited, large aperture, nanofocusing optics that is radiation resistant and very compact.

  • 46. Seiboth, Frank
    et al.
    Schropp, Andreas
    Scholz, Maria
    Wittwer, Felix
    Rödel, Christian
    Wünsche, Martin
    Ullsperger, Tobias
    Nolte, Stefan
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Parfeniukas, Karolis
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Giakoumidis, Stylianos
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wagner, Ulrich
    Rau, Christoph
    Boesenberg, Ulrike
    Garrevoet, Jan
    Falkenberg, Gerald
    Galtier, Eric C.
    Ja Lee, Hae
    Nagler, Bob
    Schroer, Christian G.
    Perfect X-ray focusing via fitting corrective glasses to aberrated optics2017Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Due to their short wavelength, X-rays can in principle be focused down to a few nanometres and below. At the same time, it is this short wavelength that puts stringent requirements on X-ray optics and their metrology. Both are limited by today’s technology. In this work, we present accurate at wavelength measurements of residual aberrations of a refractive X-ray lens using ptychography to manufacture a corrective phase plate. Together with the fitted phase plate the optics shows diffraction-limited performance, generating a nearly Gaussian beam profile with a Strehl ratio above 0.8. This scheme can be applied to any other focusing optics, thus solving the X-ray optical problem at synchrotron radiation sources and X-ray free-electron lasers.

  • 47.
    Selin, Mårten
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    von Hofsten, Olov
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    DiffractX: A Simulation Toolbox for Diffractive X-ray Optics2011Inngår i: 10TH INTERNATIONAL CONFERENCE ON X-RAY MICROSCOPY / [ed] McNulty, I; Eyberger, C; Lai, B, American Institute of Physics (AIP), 2011, Vol. 1365, s. 341-344Konferansepaper (Fagfellevurdert)
    Abstract [en]

    X-ray wavefront propagation is a powerful technique when simulating the performance of x-ray optical components. Using various numerical methods, interesting parameters such as focusing capability and efficiency can be investigated. Here we present the toolbox DiffractX, implemented in MATLAB. It contains many different wave propagation methods for the simulation of diffractive x-ray optics, including Fresnel propagation, the finite difference method (FDM), the thin object approximation, the rigorous coupled wave theory (RCWT), and the finite element method (FEM). All tools are accessed through a graphical interface, making the design of simulations fast and intuitive, even for users with little or no programming experience. The tools have been utilized to characterize realistic as well as idealized optical components. This will aid further developments of diffractive x-ray optics.

  • 48.
    Selin, Mårten
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Fogelqvist, Emelie
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Guttmann, Peter
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    3D simulation of the image formation in soft x-ray microscopes2014Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 22, nr 25, s. 30756-30768Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In water-window soft x-ray microscopy the studied object is typically larger than the depth of focus and the sample illumination is often partially coherent. This blurs out-of-focus features and may introduce considerable fringing. Understanding the influence of these phenomena on the image formation is therefore important when interpreting experimental data. Here we present a wave-propagation model operating in 3D for simulating the image formation of thick objects in partially coherent soft x-ray microscopes. The model is compared with present simulation methods as well as with experiments. The results show that our model predicts the image formation of transmission soft x-ray microscopes more accurately than previous models.

  • 49.
    Skoglund, Peter
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Ulf
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High-brightness water-window electron-impact liquid-jet microfocus source2010Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 96, nr 8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate stable high-brightness operation of an electron-impact water-jet-anode soft x-ray source. A 30 kV, 7.8 W electron beam is focused onto a 20 mu m diameter jet resulting in water-window oxygen line emission at 525 eV/2.36 nm with a brightness of 3.0x10(9) ph/(sx mu m(2)xsrxline). Monte Carlo-based modeling shows good quantitative agreement with the experiments. The source has potential to increase the x-ray power and brightness by another 1-2 orders of magnitude and fluid-dynamical jet instabilities is determined to be the most important limiting factor. The source properties make it an attractive alternative for table-top x-ray microscopy.

  • 50.
    Skoglund, Peter
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Ulf
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Electron-Impact Water-Jet Microfocus Source for Water-Window Microscopy2011Inngår i: 10th International Conference on X-Ray Microscopy / [ed] McNulty, I; Eyberger, C; Lai, B, 2011, Vol. 1365, s. 152-155Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We demonstrate high-brightness operation of an electron-impact water-jet-anode soft x-ray source with an increased power loading of 15 times compared to our previously published results, with a corresponding increase in similar to 525-eV x-ray intensity of 6.4 times. This has been accomplished by improving the vacuum pumping system and the electron focusing optics, and increasing the liquid-jet velocity. The source now operates up to 120-W e-beam power and at a 525-eV brightness of 3.5x10(9) ph/(sx mu m(2)xsrxline). The source concept has potential to increase the x-ray brightness by another order of magnitude by optimizing the e-beam focusing and upgrading the power supply. Currently, spot enlargement with increased power is determined to be the most important limiting factor.

12 1 - 50 of 76
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