Figure 2

Photos of the experimental setup holder for fibers: (a) lower cage housing the frames with LPGs; (b) upper cage with connectors; (c) the complete assembly. The sketch of the setup and the irradiation chamber (not at scale): (d) the position of the carrying cages during the descending operation; (e) the position of the cages during radiation exposure; (f) the simplified design of the two cages; 1 – irradiation channel; 2 – textile rope; 3 – upper Al cage; 4 – lower Al cage; 5 – flexible plastic tube; 6 – one of the LPGs samples; 7 – LPG’s optical fiber; 8 – connecting optical fibers for on-line measurements; 9 – fiber adaptors for connecting optical fibers; 10 – spacer for cage positioning on the irradiation channel bottom; 11 – irradiation zone.