The RaDFOS project has the ambitious goal of developing a dosimeter suitable for the next generation of particle accelerators and fusion reactors. The development of these new energy machine poses the need for new dosimetry technologies capable to measure the unprecedented level of dose expected from their operation, quantified above the MGy level. The RaDFOS dosimeter will be based on the fiber optic sensors technology.

Indeed, in recent years the research is focusing on the optical fibers for radiation dosimetry due to a number of advantages they possess over conventional sensors, primarily their immunity to electrochemical interferences and their ability to measure remotely and in real-time. To the state-of-the-art, the different fiber optic based techniques provide for an overall wide dose range and so the type of sensor can be selected depending on the dose range of the specific application. For example, luminescent based techniques generally have a high sensitivity over a low dose range (mGy to Gy), making them ideal for medical applications, while radiation induced attenuation has a lower sensitivity but is capable of monitoring at very high doses (up to several hundred kGy) allowing for monitoring in industrial applications.

Nevertheless, neither the fiber optic based dosimeters nor other dosimeters relying on different technologies, will be able to operate in the hostile environments foreseen; in the operation of the future energy machines and new devices are needed. The main objective of the RaDFOS project is to secure the possibility to monitor doses beyond the limits of present modern dosimeters, above the MGy level, that is to say in the high (H) and ultra high (UH) dose scenarios.

The realisation of this goal will represent an answer to the request for dosimeters for H and UH dose applications, like future high energy particle accelerators in high energy physics (HEP) and nuclear fusion reactors. Indeed, the present project aims to design, manufacture and operate the first OF dosimeters based on Lab On Fiber (LOF) technology, consisting in a metallo-dielectric resonator realised on the OF tip, whose key idea is to transform a ‘simple’ OF into a miniaturised and multifunctional sensor through the integration of functionalised materials and components defined at micro or nanoscale. Their miniaturised dimensions could overcome many limits in term of occupancy/environment compatibility for the use of present commercial dosimeters in HEP, and open to patent opportunities for commercial exploitations in the industrial domains where H and UH dose scenario play a key role, like present nuclear fission reactors and future nuclear fusion reactors.