Potential of Novel Optical Fibers for Proton Therapy Dosimetry

We investigate the potential of innovative optical fiber bulk materials made by the sol-gel technique for proton therapy dosimetry. These types of glass are made of amorphous silica (a-SiO
₂
) doped with either Copper (Cu) or Cerium (Ce) ions. All these optimized materials possess very interesting light emission properties when exposed to protons. Online measurement of the strong radiation-induced luminescence allows the monitoring of the time evolution of the proton flux with millisecond resolution and the cumulated proton fluence can be precisely deduced by integrating this radiation-induced luminescence signal. Preliminary tests presented here have been performed at the TRIUMF Proton Therapy facility in Vancouver, Canada, where ocular cancer is treated clinically with 74 MeV protons and a proton current of 6 nA.