Dose rate mapping in an industrial 60Co irradiator using an online photodiode-based dosimetry system
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2021
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INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 15th
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Resumo
In the radiation processing field, any irradiation process is designed to irradiate products
uniformly, but in practice, a reasonable variation in the absorbed dose through the product is
accepted. However, the irradiation of inhomogeneous or irregularly shaped products gives
rise to complex dose variations only assessed through dose mapping. It requires
complementary dosimeters bearing good spatial resolution, prompt and easy readout, and
cost-effectiveness. These features are found in silicon diodes that, despite all these
advantages, are prone to radiation damage. This damage is mitigated with photodiodes whose
thicknesses are much smaller than the minority carrier diffusion length at the anticipated
accumulated dose. In this work, an in-house dosimetry system based on a thin photodiode is
applied for online mapping dose rates, between 3.7 and 52.8 Gy/h, delivered by a Panoramic
60Co industrial facility. The operational principle of these dosimeters relies on the real-time
acquisition of the induced currents from the irradiated diode operating in the short-circuit
mode without externally applied voltage. Under this condition, the dose is assessed offline
via the integration of these current signals. The radial mapping of the radiation field is
performed by rotating the diode around the central axis of the panoramic irradiator, covering
360º at intervals of 10º. For comparative purposes, alanine dosimeters are also irradiated
together with the diode. The experimental results are benchmarked with Monte Carlo
simulations of the dose rate curves. Good agreement between the simulated values and the
readings of both dosimeters is found. 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.
Como referenciar
GONCALVES, J.A.C.; MANGIAROTTI, A.; BUENO, C.C. Dose rate mapping in an industrial 60Co irradiator using an online photodiode-based dosimetry system. In: INTERNATIONAL SYMPOSIUM ON RADIATION PHYSICS, 15th, December 6-10, 2021, Kuala Lumpur, Malaysia. Abstract... Disponível em: http://repositorio.ipen.br/handle/123456789/33681. Acesso em: 06 Feb 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.