Publication Date

2026

Document Type

Dissertation/Thesis

First Advisor

Erdelyi, Bela

Second Advisor

Shiltsev, V. D.

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

Department of Physics

Abstract

Next-generation intensity-frontier particle accelerators, such as the proposed Muon Collider and Neutrino Factories, require proton drivers capable of delivering high-intensity, short-pulse bunches. Achieving the required peak currents demands aggressive longitudinal compression, a process fundamentally limited by the extreme repulsive space-charge forces inherent to high-intensity, tightly compressed bunches.

Through the development and use of the FAST/IOTA Bunch Rotation Experiment (FI- BRE) at Fermilab as a dedicated testbed, this dissertation establishes a comprehensive physical design and simulation framework to probe these fundamental intensity limits. By isolating the dynamics of a 2.5 MeV non-relativistic proton beam (β ≈ 0.073) circulating in the Integrable Optics Test Accelerator (IOTA), we investigate regimes where the incoherent space-charge tune shift in a compressed bunch reaches extreme values (|∆Qsc| ≥ 0.5). We identify the fundamental limits of non-adiabatic “snap” bunch rotation—the technique for obtaining short bunches—in the presence of strong potential well distortion and establish the specific RF manipulation schemes required to expose these limits using IOTA’s 2.19 MHz RF system.

A central focus of this work is the characterization of phase-space dynamics through high-fidelity 3D Particle-In-Cell (PIC) simulations. These simulations predict a strong correlation between longitudinal compression ratios and transverse emittance growth in short high-intensity proton bunches, driven by the periodic crossing of integer resonances by the space-charge depressed core. By quantifying these limiting mechanisms and defining the diagnostic signatures required to observe them, this work establishes the operational foundation for a future experimental campaign in IOTA and validates the design strategies for future high- power proton drivers.

Extent

125 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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