Date of Thesis

Spring 2023

Description

The goal of this project is to find reliable parameter settings for a multi-dimensional global optimizer to optimize the performance of a large acceptance ion optical system for the requirements of nuclear physics experiments. We develop and test the Particle Swarm Optimization (PSO), a global optimization algorithm designed for continuous multi-dimensional problems, on a large acceptance particle beam separator, the High Rigidity Spectrometer (HRS) at the Facility for Rare Isotope Beams (FRIB), which is a laboratory specializing in the production and experimental study of short-lived nuclear matter. We split the HRS into two sections, the High-Transmission Beamline (HTBL) and the Spectrometer Section. The objective of the PSO is to improve the transmission rate for the Spectrometer Section and the beam spot size as well as dispersive foci for the HTBL, in both cases by adjusting the settings of the higher-order magnetic field elements—sextupoles and octupoles. We successfully improved the transmission rate of fission fragments from 57.5% to 63% in the Spectrometer Section and shrank the beam spot size in horizontal direction of 40Mg from 1.8 mm to 1.0 mm in the HTBL. Finally, we compare the performance of PSO with multiple, different internal parameter settings (inertia, acceleration). We find a significant difference in performance across the PSO parameter settings considered, with the best internal parameter setting for the PSO being (0.9, 0.45). Future work will explore the PSO parameter space for additional input particle distributions (e.g. fission fragments in the HTBL) and differently constructed objective functions to better understand the operation of the PSO in these ion optical systems.

Keywords

optimization, ion optics, spectrometer, aberration, rare-isotope, nuclear physics

Access Type

Honors Thesis

Degree Type

Bachelor of Science

Major

Physics

Minor, Emphasis, or Concentration

Mathematics

First Advisor

Matt Amthor

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