The plates supporting the sensors (Fig. 5) were welded on
a metal sheet fixed on the irradiation rig. The lead length between
the irradiation section and the data acquisition was 25
meters. Then the 3 m long aluminium coated highly radiation
resistant lead-in fibre of the sensors were spliced to a 22 m long
SM Corning Hi1060 fibre. This fibre is coated with acrylate and
is not radiation hard. However, the radiation hardness is not required
because radiation levels on this fibre are low and produce
no significant transmission degradation. Fibres were inserted in
a stainless steel tube of 2.4 mm diameter to ensure a safe operation
during the whole experiment.