Sistema y método para estimar la dosis de radiación ultravioleta durante la esterilización del nitrógeno líquido

Abstract

At the moment, there is no dosimeter that provides a real-time measurement of ultraviolet radiation dose at cryogenic temperatures during the sterilization of liquid nitrogen, because the technical parameters are defined at room temperature, and many of these change dramatically at temperature of -195 °C. In this work, a prototype of a cryogenic dosimeter based on Silicon photomultipliers (SiPM) is designed, useful for characterizing the dose of ultraviolet radiation measured in real time for quality control of cryogenic applications in medicine, biology, biotechnology and industry. In this study, a simulation with optical photons (253 nm) was performed in liquid and gaseous nitrogen, using Geant4 simulation toolkit. The results present a zone of minimal UV radiation inside a container of liquid nitrogen, and a method for estimating the radiation dose with one or more cryogenic SiPMs, located inside the container, especially in the minimum radiation zone in order to certify the absence of microorganisms in the liquid nitrogen.