Dose rate mapping of an industrial 60Co irradiator using an online photodiode-based dosimetry system

Author(s)

Goncalves, Josemary A. C. ; Mangiarotti, Alessio ; Bueno, Carmen C.

• Document type: Journal article
• Source: Radiation Physics and Chemistry; v. 200, p. 6-pg., 2022-10-04.

Abstract

In this work, a housemade dosimetry system based on a thin photodiode is applied for online mapping of dose rates, between 2.6 and 37.7 Gy/h, delivered by a Panoramic 60Co industrial facility. The operational principle of the dosimeter relies on the real-time acquisition of the induced currents from the irradiated diode operating in the short-circuit mode without externally applied voltage. The radial mapping of the radiation field is performed by rotating the diode around the central axis of the panoramic irradiator, covering 360 degrees at intervals of 18 degrees. The results are benchmarked with alanine dosimeters, Monte Carlo simulations, and reference dose rates retrieved from the facility calibration. The overall consistency of the whole data complies with the maximum response variation (8%, k = 2) recommended by the International Standard Protocols for routine dosimeters in radiation processing dosimetry. It reveals that the photodiode-dosimetry system is a reliable alternative to map dose rate fields and the effectiveness of Monte Carlo simulations as a predictive tool for dose rate measurements in an irradiator. (AU)

• FAPESP's process: 16/13116-5 - Systematic measurements of electron and proton multiple scattering with energies up to 5 MEV
• Grantee: Alessio Mangiarotti
• Support Opportunities: Research Grants - Young Investigators Grants