Growth of optical transmission loss at 850 nm in silica core optical fibers during fission reactor irradiation

Tatsuo Shikama, Tsunemi Kakuta, Minoru Narui, Tsutomu Sagawa

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6 Citations (Scopus)


Pure, OH-doped and F-doped silica core optical fibers were irradiated in a fission reactor at 400 ±1OK using an electric heater at a reactor power greater than 10 MW (20% of the full power). The temperature was not controlled well at the early stage of the reactor startup, when the temperature was about 320-340 K. The optical fibers were irradiated with a fast neutron (E > 1 MeV) flux of 3.2 × 1017 n/cm2s and a gamma dose rate of 3 × 103 Gy/s for 527 h. Optical transmission loss at 850 nm was measured in situ during irradiation. A prompt increase in optical transmission loss was observed as irradiation started, which was probably due to dynamic irradiation effects caused by short-lived and transient defects and is probably recoverable when irradiation ceases. After the prompt increase in optical transmission loss, a so-called radiation hardening was observed in fibers containing OH. Radiation hardening was also observed in 900 ppm OH-doped fiber at the second startup. The optical transmission loss increased linearly with irradiation dose, denoted as the accumulated loss, which we believe is due to irradiation-induced long-lived defects. Accumulated loss dominates radiation-induced optical transmission loss in a fission reactor irradiation.

Original languageEnglish
Pages (from-to)180-189
Number of pages10
JournalJournal of Nuclear Materials
Issue number1-3
Publication statusPublished - 1998 Mar 1

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering


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