11/08/2023
By Matthew Gagne

The UMass Biomedical Engineering & Biotechnology Program invites you to attend a doctoral dissertation defense by Matt P. Gagne on the "Development of Novel Anodized Thin-Film Radiation Sensors."

Candidate Name: Matthew P. Gagne
Degree: Doctoral
Defense Date: Friday, Nov. 17, 2023
Time: From 3 to 4 p.m.
Location: To be held remotely via Zoom. Please email matthew_gagne@student.uml.edu or erno_sajo@uml.edu for link.

Thesis/Dissertation Title: Development of Novel Anodized Thin-Film Radiation Sensors

Advisors:

  • Wil Ngwa, Ph.D., Department of Physics & Applied Physics, UMass Lowell
  • Erno Sajo, Ph.D., Department of Physics & Applied Physics, UMass Lowell

Committee Members:

  • James Egan, Ph.D., Department of Physics & Applied Physics, UMass Lowell
  • Kwok-Fan Chow, Ph.D., Department of Chemistry, UMass Lowell
  • Piotr Zygmanski, Ph.D., Department of Physics & Applied Physics, UMass Lowell and Division of Medical Physics and Biophysics, Brigham and Women's Hospital

Abstract:

Classical radiation detection technology relies on the interaction of radiation within the bulky volume of their sensors. Historically, increasing the sensitivity of a radiation detector required using costly materials, increasing the interaction volume, or including complex and fragile amplification technology. These limitations have meant that only incremental changes and improvements in radiation detection systems have been possible. As radiation use in industry, military applications, and medicine continue to increase, the need for a cost effective, light weight, and resilient radiation detectors is at an all-time high. High Energy Current (HEC) technology relies on surface level radiation interaction with thin and inexpensive materials to produce sensitive radiation sensors. Detection systems using macroscopic fabrication techniques to produce HEC technology have shown the potential for this technology in numerous applications.

In order to capitalize on the great advantages of HEC technology over historically available radiation sensors, the technology needs to be miniaturized. This work details the development, fabrication, and testing of a novel thin-film flexible and resilient radiation detector based on HEC principals. Dubbed the Anodox sensor, these prototypes are produced using a novel anodization technique using affordable of the shelf materials. They are capable of reliable radiation detection using commercial electronic reading equipment and can operate in a self-powered or minimal voltage-bias mode. These physically resilient detectors are able to accomplish these goals while having a total thickness of approximately 50 μm.

In this work, Anodox sensors are also tested for their response to electronically produced kVp x-rays. They are first characterized for their response to x-rays from an industrial x-ray tube. Following characterization, they are tested for their response in two modern medical imaging modalities. Fluoroscopy and computer tomography (CT) are two imaging modalities that play an increasingly important role in modern healthcare while also imparting significant radiation dose to patients and clinicians. These proof-of-concept tests show the viability of HEC sensors as an effective dose monitoring tool in modalities where accurate dose measurement is not currently possible. This research highlights the benefits of HEC technology in radiation detection and medicine and shows the need for the further development of this novel technology.