id,collection,dc.contributor.author,dc.date.accessioned,dc.date.available,dc.date.issued,dc.description.abstract[en],dc.format.extent,dc.identifier.sepid,dc.identifier.uri,dc.language,dc.rights.uri,dc.subject.ddc,dc.title,dc.title.subtitle,dc.type,dcterms.accessRights.openaire,dcterms.bibliographicCitation,dcterms.bibliographicCitation.doi,dcterms.isPartOf.issn,refubium.affiliation[de],refubium.mycore.derivateId,refubium.mycore.fudocsId,refubium.resourceType.isindependentpub "6f19425d-fe71-4f1e-a0e0-01cb4bcbd2ed","fub188/16","Holldack, Karsten||Bahrdt, Johannes||Balzer, Andreas||Bovensiepen, Uwe||Brhezinskaya, Maria||Erko, Alexei||Eschenlohr, Andrea||Follath, Rolf||Firsov, Alexander||Frentrup, Winfried||Le Guyader, Loic||Kachel, Torsten||Kuske, Peter||Mitzner, Rolf||Müller, Roland||Pontius, Niko||Quast, Torsten||Radu, Ilie||Schmidt, Jan-Simon||Schüßler-Langeheine, Christian||Sperling, Mike||Stamm, Christian||Trabant, Christoph||Föhlisch, Alexander","2018-06-08T03:55:29Z","2014-11-13T13:07:25.501Z","2014","Here the major upgrades of the femtoslicing facility at BESSY II (Khan et al., 2006) are reviewed, giving a tutorial on how elliptical-polarized ultrashort soft X-ray pulses from electron storage rings are generated at high repetition rates. Employing a 6 kHz femtosecond-laser system consisting of two amplifiers that are seeded by one Ti:Sa oscillator, the total average flux of photons of 100 fs duration (FWHM) has been increased by a factor of 120 to up to 106 photons s-1 (0.1% bandwidth)-1 on the sample in the range from 250 to 1400 eV. Thanks to a new beamline design, a factor of 20 enhanced flux and improvements of the stability together with the top-up mode of the accelerator have been achieved. The previously unavoidable problem of increased picosecond- background at higher repetition rates, caused by `halo' photons, has also been solved by hopping between different `camshaft' bunches in a dedicated fill pattern (`3+1 camshaft fill') of the storage ring. In addition to an increased X-ray performance at variable (linear and elliptical) polarization, the sample excitation in pump-probe experiments has been considerably extended using an optical parametric amplifier that supports the range from the near-UV to the far-IR regime. Dedicated endstations covering ultrafast magnetism experiments based on time-resolved X-ray circular dichroism have been either upgraded or, in the case of time-resolved resonant soft X-ray diffraction and reflection, newly constructed and adapted to femtoslicing requirements. Experiments at low temperatures down to 6 K and magnetic fields up to 0.5 T are supported. The FemtoSpeX facility is now operated as a 24 h user facility enabling a new class of experiments in ultrafast magnetism and in the field of transient phenomena and phase transitions in solids.","15 S.","37282","https://refubium.fu-berlin.de/handle/fub188/16220||http://dx.doi.org/10.17169/refubium-20404","ger","http://journals.iucr.org/services/copyrightpolicy.html","500 Naturwissenschaften und Mathematik::530 Physik","FemtoSpeX","a versatile optical pump–soft X-ray probe facility with 100 fs X-ray pulses of variable polarization","Wissenschaftlicher Artikel","open access","Journal of Synchrotron Radiation. - 21 (2014), 5, S. 1090-1104","10.1107/S1600577514012247","1600-5775","Physik","FUDOCS_derivate_000000004138","FUDOCS_document_000000021273","no"