Space Charge And Lattice Driven Resonances at the CERN Injectors

Asvesta, Foteini; Ασβεστά, Φωτεινή

dc.contributor.author	Asvesta, Foteini	en
dc.contributor.author	Ασβεστά, Φωτεινή	el
dc.date.accessioned	2020-12-01T12:47:25Z
dc.date.available	2020-12-01T12:47:25Z
dc.date.issued	2020-12-01
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/52136
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.19834
dc.rights	Default License
dc.subject	Accelerator Physics	en
dc.subject	Φυσική επιταχυντών	el
dc.subject	Beam dynamics	en
dc.subject	Δυναμική σε δέσμες	el
dc.subject	Beam resonances	en
dc.subject	Συντονισμοί σε επιταχυντές	el
dc.subject	Higher order beam dynamics	en
dc.subject	Nonlinear beam dynamics	en
dc.subject	Μη γραμμική δυναμική	el
dc.subject	Space charge in beams	en
dc.subject	Φαινόμενο χωρικού φορτίου σε δέσμες	el
dc.title	Space Charge And Lattice Driven Resonances at the CERN Injectors	en
dc.title.alternative	Φαινόμενο Χωρικού φορτίου και συντονισμοί στους επιταχυντές του CERN	el
dc.contributor.department	Division of Electromagnetics, Electrooptics and Electronic Materials	el
heal.type	doctoralThesis
heal.classification	Accelerator physics	en
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2020-09
heal.abstract	The present dissertation focuses on the space charge phenomena in the presence of betatron resonances in the CERN Injectors and in particular the Proton Synchrotron (PS) and the Proton Synchrotron Booster (PSB). Space charge dominates the dynamics in high brightness and low energy machines as the injectors and it is typically one of the main performance limitations for operation. In the PS, losses are observed for vertical tunes above , especially for beams with large space charge tune shift. The work presented here shows that this behaviour is associated to structure resonances excited by space charge due to the highly symmetric accelerator lattice of the PS, typical for first generation alternating gradient synchrotrons. Simulation studies reveal the incoherent nature of the resonance observed at while the analytical calculation of the Resonance Driving Terms (RDT) generated by the space charge potential shows that the operational working point of the PS is surrounded by multiple space charge driven incoherent resonances. Similarly, Frequency Map Analysis (FMA) studies demonstrate the excitation of resonances in simulations while revealing that the mechanism that leads to the observed losses is the periodic crossing of resonances. Experimental and simulation studies showcase the response of the operational high brightness beam in the PS in terms of losses and emittance growth. With the use of lower brightness beams lattice driven resonances excited by machine errors are identified and compensated. Finally, measurements and simulations on both lattice driven and space charge driven resonances illustrate the different behaviour of the beam loss depending on the source of the resonance excitation and on the beam brightness. The last part of the thesis concerns studies in the PSB, where the resonance under study is the coupling resonance excited by space charge, referred to as Montague resonance. The analytical approach of the (RDT) calculations reveals that the machine could be operated in a different tune regime, namely the Q4Q3, where the resonance is suppressed. Measurements and simulations with various crossing speeds of the resonance, show the emittance exchange that it causes in the operational tune regime (Q4Q4) while the suppression in the regime Q4Q3 is demonstrated with the preservation of the emittance in both planes during the crossing. The interplay of the Montague with the excitation of the coupling in 2nd order through skew quadrupole-like errors is also studied in both measurements and simulations.	en
heal.sponsor	CERN	en
heal.advisorName	Hizanidis, Kyriakos	en
heal.committeeMemberName	Fikioris, George	en
heal.committeeMemberName	Bartosik, Hannes	en
heal.committeeMemberName	Glytsis, Elias	en
heal.committeeMemberName	Kominis, Yannis	en
heal.committeeMemberName	Papaphilippou, Yannis	en
heal.committeeMemberName	Tigelis, Ioannis	en
heal.committeeMemberName	Tsipolitis, Georgios	en
heal.academicPublisher	Σχολή Ηλεκτρολόγων Μηχανικών και Μηχανικών Υπολογιστών	el
heal.academicPublisherID	ntua
heal.numberOfPages	170 p.	en
heal.fullTextAvailability	false