000474539 001__ 474539
000474539 005__ 20231010145001.0
000474539 0247_ $$2URN$$aurn:nbn:de:gbv:18-ediss-94297
000474539 037__ $$aPUBDB-2022-00857
000474539 041__ $$aEnglish
000474539 1001_ $$0P:(DE-H253)PIP1080593$$aBellandi, Andrea$$b0$$eCorresponding author$$gmale
000474539 245__ $$aLLRF Control Techniques for the European XFEL Continuous Wave Upgrade$$f2017-09-01 - 2021-02-28
000474539 260__ $$aHamburg$$bUniversität Hamburg $$c2021
000474539 300__ $$a125
000474539 3367_ $$2DataCite$$aOutput Types/Dissertation
000474539 3367_ $$2ORCID$$aDISSERTATION
000474539 3367_ $$2BibTeX$$aPHDTHESIS
000474539 3367_ $$02$$2EndNote$$aThesis
000474539 3367_ $$0PUB:(DE-HGF)11$$2PUB:(DE-HGF)$$aDissertation / PhD Thesis$$bphd$$mphd$$s1696941986_278290
000474539 3367_ $$2DRIVER$$adoctoralThesis
000474539 500__ $$aA. Bellandi:  thesis contains copyright-transferred articles
000474539 502__ $$aDissertation, University of Hamburg, 2021$$bDissertation$$cUniversity of Hamburg$$d2021
000474539 520__ $$aIn this doctoral thesis, possible solutions for superconducting cavity control systems operating in the Continuous Wave(CW) regime are discussed and analyzed. The paper focuses on the requirements for adding a CW mode of operationto European XFEL alongside the existing pulsed mode of operation. The main challenge from a control system point of view stems from the need to use a loaded quality factor (QL) in the range of 10e7-10e8. Such a (QL) is an order of magnitude greater than the actual value that is used in the pulsed mode of operation. As aresult, the cavity tune is more sensitive to microphonic effects. For this reason, active noise compensation techniques are required in order to limit the overall power consumption of the accelerating system, and to increase the energy stability of the accelerated beam. Another effect present in the future upgrade are ponderomotive instabilities. These instabilities result from the nonlinear coupling between the Lorentz force-induced detuning and the cavity acceleration field. These in-stabilities are then analyzed and a possible compensation scheme is proposed. In order to obtain a precise estimate of the cavity detuning, a real-time detuning estimator has been developed. This component, necessary for resonance control systems, is also used for the estimation of the cavity quality factor in order to realize a quench detection system. The last topic is about the linearization of radio frequency amplifiers based on vacuum tubes used to produce power the superconducting cavities. The reason for doing a linearization of these amplifiers is the improvement of the field stability and the simplification of setup procedures of the RF control system. For this study, Klystrons and Induction Output Tube (IOT) amplifiers were used.
000474539 536__ $$0G:(DE-HGF)POF4-621$$a621 - Accelerator Research and Development (POF4-621)$$cPOF4-621$$fPOF IV$$x0
000474539 536__ $$0G:(DE-HGF)2015_IFV-VH-GS-500$$aPHGS, VH-GS-500 - PIER Helmholtz Graduate School (2015_IFV-VH-GS-500)$$c2015_IFV-VH-GS-500$$x1
000474539 693__ $$0EXP:(DE-H253)XFEL(machine)-20150101$$1EXP:(DE-H253)XFEL-20150101$$5EXP:(DE-H253)XFEL(machine)-20150101$$aXFEL$$eFacility (machine) XFEL$$x0
000474539 7001_ $$0P:(DE-H253)PIP1014945$$aBranlard, Julien$$b1$$eThesis advisor
000474539 7001_ $$0P:(DE-H253)PIP1032393$$aHillert, Wolfgang$$b2$$eThesis advisor
000474539 8564_ $$uhttps://ediss.sub.uni-hamburg.de/handle/ediss/9139
000474539 8564_ $$uhttps://bib-pubdb1.desy.de/record/474539/files/LLRF_Control_Techniques_for_the_European_XFEL_Continuous_Wave_Upgrade__Copy_%285%29.pdf$$yRestricted
000474539 8564_ $$uhttps://bib-pubdb1.desy.de/record/474539/files/LLRF_Control_Techniques_for_the_European_XFEL_Continuous_Wave_Upgrade__Copy_%285%29.pdf?subformat=pdfa$$xpdfa$$yRestricted
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000474539 9101_ $$0I:(DE-588b)2008985-5$$6P:(DE-H253)PIP1080593$$aDeutsches Elektronen-Synchrotron$$b0$$kDESY
000474539 9101_ $$0I:(DE-588b)2008985-5$$6P:(DE-H253)PIP1014945$$aDeutsches Elektronen-Synchrotron$$b1$$kDESY
000474539 9101_ $$0I:(DE-H253)_CFEL-20120731$$6P:(DE-H253)PIP1032393$$aCentre for Free-Electron Laser Science$$b2$$kCFEL
000474539 9101_ $$0I:(DE-HGF)0$$6P:(DE-H253)PIP1032393$$aExternal Institute$$b2$$kExtern
000474539 9131_ $$0G:(DE-HGF)POF4-621$$1G:(DE-HGF)POF4-620$$2G:(DE-HGF)POF4-600$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$aDE-HGF$$bForschungsbereich Materie$$lMaterie und Technologie$$vAccelerator Research and Development$$x0
000474539 9141_ $$y2021
000474539 920__ $$lyes
000474539 9201_ $$0I:(DE-H253)MSK-20120731$$kMSK$$lStrahlkontrollen$$x0
000474539 980__ $$aphd
000474539 980__ $$aVDB
000474539 980__ $$aI:(DE-H253)MSK-20120731
000474539 980__ $$aUNRESTRICTED