# FLA

 2017-04-2715:21 [PUBDB-2017-02034] Journal Article et al Mitigation of the Hose Instability in Plasma-Wakefield Accelerators 17th Advanced Accelerator Concepts Workshop, AAC 2016, Meeting locationNational Harbor, Maryland, USA, 31 Jul 2016 - 5 Aug 2016 Physical review letters 118(17), 174801 (2017) [10.1103/PhysRevLett.118.174801]   Current models predict the hose instability to crucially limit the applicability of plasma-wakefield accelerators. By developing an analytical model which incorporates the evolution of the hose instability over long propagation distances, this work demonstrates that the inherent drive-beam energy loss, along with an initial beam-energy spread, detunes the betatron oscillations of beam electrons and thereby mitigates the instability. [...] OpenAccess: PDF; External link: Fulltext 2017-04-2516:03 [PUBDB-2017-01893] Talk (non-conference) et al High-quality electron beam generation in plasma-based accelerators Neumann-Institut für Computing - Vortragsveranstaltung des Wissenschaftlichen Rates, Meeting locationDarmstadt, GSI Darmstadt, Germany, 20 Apr 2017 - 21 Apr 2017 2017-04-2515:52 [PUBDB-2017-01891] Talk (non-conference) (Invited) et al Stable acceleration of high-quality beams in plasma-based accelerators Seminar, Meeting locationDaresbury, Cockcroft Institute, Daresbury, UK, England, 6 Feb 2017 A number of recent theoretical works proposed various promising methods for the generation of high-quality witness beams in present and future plasma-wakefield accelerators. However, before such beams are to be used in applications, the crucial question of the stable, quality-preserving acceleration and transport needs to be studied. [...] 2017-04-2515:00 [PUBDB-2017-01886] Contribution to a conference proceedings et al Performance Analysis of the European XFEL SRF cavities, fromvertical test to operation in modules 28th Linear Accelerator Conference, LINAC2016, Meeting locationEast Lansing, USA, 25 Sep 2016 - 30 Sep 2016 6 pp., (2016) [10.3204/PUBDB-2017-01886]   More than 800 resonators have been fabricated, verti-cally qualified and operated in module tests before the accelerating module installation in the linac, which will be completed before the conference. An analysis of this experience, with correlation of the final cavity perfor-mances with production, preparation and assembly stages, is underway and at the time of the conference a summary of the activities will be available.. OpenAccess: PDF; 2017-04-2514:46 [PUBDB-2017-01883] Preprint/Report Schaffran, J. Analysis of the cool down related cavity performance of the European XFEL vertical acceptance tests [arXiv:1609.06503]   It has been reported that the cool down dynamics across $T_c$ has a significant influence on the observed quality factors $Q_0$ of a cavity, which is most likely due to trapped flux. In this document we show the results of the investigation if such a correlation can be observed during the European XFEL cavity production.. OpenAccess: PDF; External link: Fulltext 2017-04-2514:30 [PUBDB-2017-01882] Journal Article et al Performance in the vertical test of the 832 nine-cell 1.3 GHz cavities for the European X-ray Free Electron Laser   The successful production and associated vertical testing of over 800 superconducting 1.3 GHz accelerating cavities for the European X-ray Free Electron Laser (XFEL) represents the culmination of over 20 years of superconducting radio-frequency R&D. The cavity production took place at two industrial vendors under the shared responsibility of INFN Milano–LASA and DESY. [...] OpenAccess: PDF; External link: Fulltext 2017-04-2412:48 [PUBDB-2017-01816] Preprint/Report Wenskat, M. Automated Optical Inspection and Image Analysis of Superconducting Radio-Frequency Cavities [DESY-17-061; arXiv:1704.06081]   The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. For an investigation of this inner surface of more than 100 cavities within the cavity fabrication for the European XFEL and the ILC HiGrade Research Project, an optical inspection robot OBACHT was constructed. [...] OpenAccess: PDF; 2017-04-2412:46 [PUBDB-2017-01815] Preprint/Report Wenskat, M. Optical Surface Properties and their RF Limitations of European XFEL Cavities [DESY-17-060; arXiv:1704.06080]   The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. The industrial fabrication of cavities for the European X-Ray Free Electron Laser (XFEL) and the International Linear Collider (ILC) HiGrade Research Project allowed for an investigation of this interplay. [...] OpenAccess: PDF; 2017-03-2815:16 [PUBDB-2017-01486] Preprint/Report et al Chirp mitigation of plasma-accelerated beams using a modulated plasma density [arXiv:1603.08489]   Plasma-based accelerators offer the possibility to drive future compact light sources and high-energy physics applications. Achieving good beam quality, especially a small beam energy spread, is still one of the major challenges. [...] OpenAccess: PDF; 2017-01-3015:02 [PUBDB-2017-00798] Book/Report/Dissertation / PhD Thesis Wichmann, K. Combination of the inclusive DIS $e^{\pm}p$ cross sections from HERA, QCD and EW analyses and the need for low-$Q^2$ higher-twist corrections [DESY-THESIS-2017-004] DESY-THESIS 197 pp., (2017) [10.3204/PUBDB-2017-00798]   A combination of the inclusive lepton-proton cross sections from the ZEUS and H1 experiments is presented. The data are combined taking into account correlations of the systematic uncertainties of the measurements. [...] OpenAccess: desy-thesis-17-004.title - PDF; PhD_thesis_V_Myronenko - PDF;