Study and Mitigation of Transverse Resonances with Space Charge Effects at the University of Maryland Electron Ring

dc.contributor.advisorAntonsen, Thomas Men_US
dc.contributor.advisorBeaudoin, Brian Len_US
dc.contributor.authorDovlatyan, Levonen_US
dc.contributor.departmentPhysicsen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2021-02-14T06:36:17Z
dc.date.available2021-02-14T06:36:17Z
dc.date.issued2020en_US
dc.description.abstractResearch at the intensity frontier of particle physics has led to the consideration of accelerators that push the limits on achievable beam intensities. At high beam intensities Coulomb interactions between charged particles generate a space charge force that complicates beam dynamics. The space charge force can lead to a range of nonlinear, intensity- limiting phenomena that result in degraded beam quality and current loss. This is the central issue faced by the next generation of high-intensity particle accelerators. An improved understanding of the interaction of the space charge forces and transverse particle motion will help researchers better design around these limiting issues. Furthermore, any scheme able to mitigate the impacts of such destructive interactions for space charge dominated beams would help alleviate a significant limitation in reaching higher beam intensities. Experimental work addressing these issues is presented using the University of Maryland Electron Ring (UMER). This dissertation presents experimental studies of space charge dominated beams, and in particular the resonant interaction between the transverse motion of the beam and the periodic perturbations that occur due to the focusing elements in a circular ring. These interactions are characterized in terms of the tune shifts, Qx and Qy, that are the number of transverse oscillations (in and out of the plane of the ring) per trip around the ring. Resonances occur for both integer and half-integer values of tune shift. Particle tune measurement tools and resonance detection techniques are developed for use in the experiment. Results show no shift for either the integer (Qx = 7.0, Qy = 7.0) or half-integer (Qx = 6.5, Qy = 6.5) resonance bands as a function of space charge. Accepted theory predicts only a shift in the half-integer resonance case. A second experiment testing the potential mitigation of transverse resonances through nonlinear detuning of particle orbits from resonance driving terms is also presented. The study included the design, simulation, and experimental test of a quasi-integrable accelerator lattice based on a single nonlinear octupole channel insert. Experiments measured a nonlinear amplitude dependent tune shift within the beam on the order of ∆Qx ≈ 0.02 and ∆Qy ≈ 0.03. The limited tolerances on accelerator steering prevented measuring any larger tune shifts.en_US
dc.identifierhttps://doi.org/10.13016/8pmc-vtcv
dc.identifier.urihttp://hdl.handle.net/1903/26821
dc.language.isoenen_US
dc.subject.pqcontrolledApplied physicsen_US
dc.subject.pqcontrolledPhysicsen_US
dc.subject.pqcontrolledPlasma physicsen_US
dc.subject.pquncontrolledacceleratoren_US
dc.subject.pquncontrolledAccelerator physicsen_US
dc.subject.pquncontrolledBeam physicsen_US
dc.subject.pquncontrollednonlinear integrable opticsen_US
dc.subject.pquncontrolledresonancesen_US
dc.subject.pquncontrolledspace chargeen_US
dc.titleStudy and Mitigation of Transverse Resonances with Space Charge Effects at the University of Maryland Electron Ringen_US
dc.typeDissertationen_US

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