Radiation-induced absorption and luminescence are measured in the visible s
pectral region in H-2-loaded and as-drawn fibers with KU and KS-4V silicas
in the core in the process of gamma-irradiation (Co-60-source). The induced
absorption in H-2-loaded fibers is shown to be much lower than in as-drawn
fibers, at least up to 1.2 MGy. A 'blue' band prevails in the luminescence
spectra of all the fibers. Its intensity is greater in a KS-4V fiber than
in a KU fiber. It is also somewhat greater in H-2-loaded fibers than in unl
oaded ones.
The luminescence lifetime in a KU fiber has been measured under excitation
with a pulsed reactor to be 100 mu s at lambda=488 nm and 60 mu s at lambda
=633 nm. It is concluded that the 'blue' radioluminescence cannot be attrib
uted either to relaxation of the oxygen-deficient center or to Cerenkov emi
ssion.
A fabrication technology of radiation-hardened H-2-containing fibers with a
hermetic aluminum coating is reported. Such fibers appear to be the best c
andidates for various applications in radiation environments.