Gubaidulin, Vadim (2023)
Transverse instability mitigation in hadron synchrotrons using electron lenses.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00023241
Dissertation, Erstveröffentlichung, Verlagsversion
Kurzbeschreibung (Abstract)
High-intensity beams in ring accelerators are subject to several destabilising effects. Among them are transverse beam instabilities that cause severe beam losses. These instabilities are considered at the design stage of any accelerator. One of the ways to suppress the instability is Landau damping. Landau damping is caused by energy exchange between the incoherent and coherent motion of the beam's particles. In this work, a novel way to provide Landau damping is introduced and studied.
A pulsed electron lens produces a betatron tune shift in a hadron bunch as a function of the longitudinal coordinates, which is a longitudinal detuning. An example of transverse detuning is the tune shifts due to octupole magnets. This work considers a pulsed electron lens as a measure to mitigate transverse instabilities.
Using a detailed analytical description with the Vlasov formalism, the coherent properties of the longitudinal and transverse detuning are presented. The analytical predictions are compared with the results of the particle tracking simulations. A pulsed electron lens is demonstrated to be a source of tune spread with two components: the static one, leading to Landau damping; and the dynamic one, leading to effective impedance modification, an effect demonstrated analytically and in the particle tracking simulations. The effective impedance modification can be significant for beam stability due to devices with longitudinal detuning, especially for the nonzero head-tail modes. The Vlasov formalism is extended to include the combination of longitudinal and transverse detuning. As a possible application for SIS100 (FAIR at GSI Darmstadt, Germany), a combination of a pulsed electron lens with octupole magnets is considered.
Additionally, the results of experiments in the existing ring SIS18 are presented. The feasibility of an electron lens for Landau damping was studied experimentally. It was shown that increasing the current of the electron lens weakens the instability. However, more experiments with a larger range of parameters are necessary to demonstrate the reproducibility of this result. Experiments indicated a potential limiting factor for the usage of electron lenses in SIS18.
Typ des Eintrags: | Dissertation | ||||
---|---|---|---|---|---|
Erschienen: | 2023 | ||||
Autor(en): | Gubaidulin, Vadim | ||||
Art des Eintrags: | Erstveröffentlichung | ||||
Titel: | Transverse instability mitigation in hadron synchrotrons using electron lenses | ||||
Sprache: | Englisch | ||||
Referenten: | Boine-Frankenheim, Prof. Dr. Oliver ; Métral, Dr. Elias | ||||
Publikationsjahr: | 2023 | ||||
Ort: | Darmstadt | ||||
Kollation: | X, 122 Seiten | ||||
Datum der mündlichen Prüfung: | 30 Januar 2023 | ||||
DOI: | 10.26083/tuprints-00023241 | ||||
URL / URN: | https://tuprints.ulb.tu-darmstadt.de/23241 | ||||
Kurzbeschreibung (Abstract): | High-intensity beams in ring accelerators are subject to several destabilising effects. Among them are transverse beam instabilities that cause severe beam losses. These instabilities are considered at the design stage of any accelerator. One of the ways to suppress the instability is Landau damping. Landau damping is caused by energy exchange between the incoherent and coherent motion of the beam's particles. In this work, a novel way to provide Landau damping is introduced and studied. A pulsed electron lens produces a betatron tune shift in a hadron bunch as a function of the longitudinal coordinates, which is a longitudinal detuning. An example of transverse detuning is the tune shifts due to octupole magnets. This work considers a pulsed electron lens as a measure to mitigate transverse instabilities. Using a detailed analytical description with the Vlasov formalism, the coherent properties of the longitudinal and transverse detuning are presented. The analytical predictions are compared with the results of the particle tracking simulations. A pulsed electron lens is demonstrated to be a source of tune spread with two components: the static one, leading to Landau damping; and the dynamic one, leading to effective impedance modification, an effect demonstrated analytically and in the particle tracking simulations. The effective impedance modification can be significant for beam stability due to devices with longitudinal detuning, especially for the nonzero head-tail modes. The Vlasov formalism is extended to include the combination of longitudinal and transverse detuning. As a possible application for SIS100 (FAIR at GSI Darmstadt, Germany), a combination of a pulsed electron lens with octupole magnets is considered. Additionally, the results of experiments in the existing ring SIS18 are presented. The feasibility of an electron lens for Landau damping was studied experimentally. It was shown that increasing the current of the electron lens weakens the instability. However, more experiments with a larger range of parameters are necessary to demonstrate the reproducibility of this result. Experiments indicated a potential limiting factor for the usage of electron lenses in SIS18. |
||||
Alternatives oder übersetztes Abstract: |
|
||||
Status: | Verlagsversion | ||||
URN: | urn:nbn:de:tuda-tuprints-232414 | ||||
Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 530 Physik | ||||
Fachbereich(e)/-gebiet(e): | 18 Fachbereich Elektrotechnik und Informationstechnik 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Teilchenbeschleunigung und Theorie Elektromagnetische Felder > Beschleunigerphysik 18 Fachbereich Elektrotechnik und Informationstechnik > Institut für Teilchenbeschleunigung und Theorie Elektromagnetische Felder |
||||
Hinterlegungsdatum: | 23 Feb 2023 13:11 | ||||
Letzte Änderung: | 27 Feb 2023 15:27 | ||||
PPN: | |||||
Referenten: | Boine-Frankenheim, Prof. Dr. Oliver ; Métral, Dr. Elias | ||||
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 30 Januar 2023 | ||||
Export: | |||||
Suche nach Titel in: | TUfind oder in Google |
Frage zum Eintrag |
Optionen (nur für Redakteure)
Redaktionelle Details anzeigen |