Time-resolved dose measurements of linear accelerator pulses using a fibre optic sensor: Applications and challenges

Abstract

We present time-resolved radioluminescence (RL) measurements from P-doped silica optical fibre, demonstrating potential utility in pulsed source dosimetry. When subjected to 140 MU/min from a 6 MV photon linac source, a 220 µm-core fibre has produced a RL response of 720 ± 20 photon counts/pulse from a saw-tooth ~ 40 µs duration return-to-baseline waveform. Conversely, the Cerenkov stem signal within the radiation insensitive carrier fibre is observed to offer an amplitude amounting to a little less than 3% of that of the P-doped fibre, the sharply spiked response being of ~ 2 µs duration. On the basis of these results, the practical applications and the challenges in the establishment of an effective dosimetry system are discussed.