Type
Text
Type
Thesis
Advisor
Du, Xu | Belomestnykh, Sergey | Hemmick, Thomas | Tsybychev, Dmitri.
Date
2014-12-01
Keywords
Physics | Bead Pull, BNL3, Coaxial to Dual-Ridge Waveguide, Energy Recovery Linac, Higher Order Modes, HOM Coupler
Department
Department of Physics (Scientific Instrumentation).
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76674
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
A next generation Energy Recovery Linac (ERL) is under development in the Collider-Accelerator Department at Brookhaven National Laboratory (BNL). This ERL uses a superconducting radio frequency (SFR) cavity to produce an electric field gradient ideal to accelerate charged particles. As with many accelerators, higher-order modes (HOMs) can be induced by a beam of charged particles traversing the linear accelerator cavity. The excitation of these modes can result in problematic single and multi-bunch effects and also produce undesirable heat loads to the cryogenic system. Understanding HOM prevalence and structure inside the accelerator cavity is crucial for devising a procedure for extracting HOM power and promoting excellent beam quality. In this work, a method was created to identify and characterize HOMs using a perturbation technique on a copper (Cu) cavity prototype of the BNL3 linac and a double λ /4 crab cavity. Both analyses and correlation between simulated and measured results are shown. A coaxial to dual-ridge waveguide HOM coupler was designed, constructed and implemented to extract power from HOMs simultaneously making an evanescent fundamental mode for the BNL3 cavity. A full description of the design is given along with a simulated analysis of its performance. Comparison between previous HOM coupler designs as well as correspondence between simulation and measurement is also given. | 66 pages
Recommended Citation
Marques, Carlos, "A Comprehensive Investigation and Coupler Design for Higher-Order Modes in the BNL Energy Recovery Linear Accelerator" (2014). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2558.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2558