RESUMEN
We demonstrate the feasibility of resetting and reusing dosimeters exploiting the measurement of the infrared radiation-induced attenuation (IR-RIA) in phosphosilicate optical fibers (OFs) to provide point or distributed dose measurements in radiation environments. To bleach the room temperature stable IR-RIA, we used the photobleaching (PB) phenomenon. The PB efficiency was evaluated for different wavelengths in the [400-1100] nm range. The best identified PB resetting condition consists in using a continuous-wave Argon-ion laser at 514 nm. This treatment successfully bleached â¼97% of the IR-RIA at 1550 nm of a 30 m-long P-doped single mode optical fiber X-ray irradiated at a dose of 100 Gy. Successive re-irradiations of the same OF sample, regenerated after each run, confirm that the dosimeter keeps the same calibration curve during the whole process.
RESUMEN
The potential of fiber-based sensors to monitor the fluence of atmospheric neutrons is evaluated through accelerated tests at the TRIUMF Neutron Facility (TNF) (BC, Canada), offering a flux approximatively 109 higher than the reference spectrum observed under standard conditions in New York City, USA. The radiation-induced attenuation (RIA) at 1625 nm of a phosphorus-doped radiation sensitive optical fiber is shown to linearly increase with neutron fluence, allowing an in situ and easy monitoring of the neutron flux and fluence at this facility. Furthermore, our experiments show that the fiber response remains sensitive to the ionization processes, at least up to a fluence of 7.1 × 1011 n cm-², as its radiation sensitivity coefficient (~3.36 dB km-1 Gy-1) under neutron exposure remains very similar to the one measured under X-rays (~3.8 dB km-1 Gy-1) at the same wavelength. The presented results open the way to the development of a point-like or even a distributed dosimeter for natural or man-made neutron-rich environments. The feasibility to measure the dose caused by the neutron exposure during stratospheric balloon experiments, or during outer space missions, is presented as a case study of a potential future application.