Date of Award

Fall 12-2022

Document Type


Degree Name

Doctor of Philosophy (PhD)


Electrical & Computer Engineering


Electrical and Computer Engineering

Committee Director

Helmut Baumgart

Committee Member

Linda Vahala

Committee Member

Shu Xiao

Committee Member

Fay Hannon

Committee Member

Gianluigi Ciovati

Committee Member

Shaoheng Wang


Electron beam (e-beam) irradiation is an advanced method for removing the emerging organic contaminants in wastewater, such as 1,4-dioxane, and per- and polyfluoroalkyl substances (PFAS), which have the potential to be regulated in the near future but are difficult to degrade by conventional treatment methods. This dissertation was based on a collaborating study between Jefferson Lab (Jlab) and Hampton Roads Sanitation District (HRSD) to evaluate the impacts of e-beam irradiation on the degradation of 1,4-dioxane and PFAS. It presents the detailed design of an e-beam irradiation beamline, the beamline simulation using general particle tracer (GPT), the installation, and the successful commissioning. The beamline is an extended section to the Upgraded Injector Test Facility (UITF) at Jlab, which is a continuous wave (CW), superconducting radio frequency (SRF) linear accelerator with an energy up to 10 MeV. To let the sample volume receive a significant and uniform dose distribution, the sample target was designed by investigating the dose distribution simulated with a Monte-Carlo code, FLUKA. The optimized beam energy was 8 MeV and the beam current for irradiation was ∼ 100 nA. With the use of a solenoid and a raster, the electron beam was expanded to the optimized size, 1σ ∼ 15 mm, at the sample target. This dissertation also presents the irradiation experiments for 64 1,4-dioxane samples and 48 PFAS samples in different water matrices, including real wastewater, which were prepared and analyzed by HRSD. The absorbed doses of samples were obtained by designing a new method that combines the FLUKA simulation and dose mapping experiments. The irradiation results showed that around 95% of 1,4-dioxane was removed at a low dose of ∼ 2 kGy, and PFAS was possibly removed at a lower dose compared to similar research.

This work is a first implementation of SRF technology for wastewater irradiation. It provides a valuable new research platform for wastewater remediation. This will be in support of future industrial applications of advanced SRF technologies and better understanding of the effect of e-beam irradiation on wastewater or water treatment.


Supplemental files (FLUKA simulation files, GPT simulation files, and SUPERFISH input files) are included in an additional zipped file.


In Copyright. URI: This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Copyright, 2023, by Xi Li, All Rights Reserved.