Optical phenomena in KU-1 silica core fiber waveguides under pulsed reactor irradiation

Non-linear optical properties of silica-glass-core-fiber waveguides under intense pulsed reactor irradiation

“…The techniques of optical measurements during pulsed irradiation of BARS-6 fission reactor (IPPE, pulse duration 80 ls, dose per pulse <5.5 · 10 12 n/cm 2 (9 Gy), dose rate <7 · 10 16 n/cm 2 s (1.1 · 10 5 Gy/s)) have been presented elsewhere [4,5]. The optical signals and the neutron flux were measured simultaneously.…”

“…The time dependencies of RLE of KU-1 fibers under pulsed reactor irradiation were measured in [4]. The effect of optical loss was eliminated, by using the linear approximation.…”

“…The effect of optical loss was eliminated, by using the linear approximation. The time dependence of light emission has two components: fast and slow [4].…”

“…As for optical response, two types of non-linear behaviors of optical fibers have been observed in the visible region. First, during pulsed reactor irradiation, a sub-linear dose rate dependence of the intensity of RLE was observed [4]. Second, it was found that radiation-induced optical properties depend on the light intensity in the fibers, during steady-state gamma or pulsed reactor irradiation [5][6][7].…”

“…Accordingly, the efficiency of RLE and the TOL are calculated from two measurements: the light emission intensity only (no probing light) and the intensity of simultaneous light emission and probing light transmitted through a fiber [4]. The radiation-induced light amplification is a typical effect showing the dependence of optical properties on the light-intensity.…”