6–10 Jul 2026
University of the Western Cape
Africa/Johannesburg timezone
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Germanium-doped Fiber Optic Sensors for High-Radiation Dosimetry

7 Jul 2026, 12:20
20m
Lecture Hall DL3 (University of the Western Cape)

Lecture Hall DL3

University of the Western Cape

Oral Presentation Track F - Applied Physics Applied Physics

Speaker

Timothy Brooks (University of Johannesburg)

Description

Accurate radiation dosimetry in high-energy and high-radiation environments remains a critical challenge for applications in particle physics, nuclear engineering, and space systems. This study investigates the performance of germanium-doped fiber optic sensors as robust and sensitive platforms for radiation monitoring under extreme conditions. In this study, a germanium-doped FBG sensor was irradiated with high-energy protons at the CERN IRRAD facility to 1.85 MGy to investigate radiation-induced effects and assess its suitability for dosimetry. The sensor response was characterized by comparing temperature sensitivity before and after irradiation, enabling evaluation of radiation-induced changes in the thermo-optic and strain-optic coefficients. Additionally, the bragg wavelength shift, spectra width and power shift as a function of accumulated dose were conducted to quantify the impact of proton irradiation on the grating structure. The results show measurable modifications in sensor behavior post-irradiation, including changes in baseline wavelength and sensitivity. A calibration procedure was developed to correlate the radiation-induced spectral shift with absorbed dose, demonstrating the feasibility of using germanium-doped FBGs as passive dosimeters. The relationship between wavelength shift and dose was analyzed in terms of linearity, repeatability, and stability. This work demonstrates that germanium-doped FBG sensors can serve as compact, immune-to-electromagnetic-interference dosimeters, with potential applications in high-radiation environments such as particle accelerators, nuclear facilities, and space systems.

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Author

Timothy Brooks (University of Johannesburg)

Co-authors

Abdool Sattar Cassim (University of Johannesburg) Daniel Madyira (University of Johannesburg) Doomnull Unwuchola Emmanuel Igumbor (University of Johannesburg) Loan Truong (University Of Johannesburg) Matthew Peter Connell (University of Johannesburg) Samuel Temaugee (University of Johannesburg) Simon Connell (University of Johannesburg) Xola Mapekula (University of Johannesburg)

Presentation materials

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