Influence of <formula formulatype="inline"><tex Notation="TeX">${\hbox{O}}_2$</tex></formula>-Loading Pretreatment on the Radiation Response of Pure and Fluorine-Doped Silica-Based Optical Fibers

Abstract

We investigated the impact of an oxygen preloading on pure-silica-core or fluorine-doped-core fiber responses to high irradiation doses (up to 1 MGy SiO ). Oxygen enrichment was achieved through a diffusion-based technique, and the long-term presence of O molecules was confirmed by micro-Raman experiments. Online radiation induced attenuation (RIA) experiments were carried out in both the pristine and the O -loaded optical fibers to investigate the differences induced by this pretreatment in the UV and visible ranges. Contrary to results recently published on the positive impact of O on infrared RIA, our results reveal a RIA increase with O presence. Data are analyzed in order to better understand the microscopic processes involved during the irradiation and to evaluate possible hardening developments.

Near infrared radio-luminescence of O2 loaded radiation hardened silica optical fibers: A candidate dosimeter for harsh environments

“…10 Detailed measurements of the oxygen profile and repartition along the fiber diameter were performed with the spatial resolution of about 5 lm, indicating that the concentration is constant within the experimental error. 7 Moreover, performing similar measurements on OFs kept at room temperature for more than 1.5 years after the O 2 -loading treatment revealed that an O 2 out-diffusion mechanism cannot occur. This interesting property confirmed the potential of such components as sensors combining both sensitivity and longevity.…”

“…In this paper, we explore the potential of radiation hardened (Rad-Hard) OFs subjected to O 2 loading treatment to develop an efficient fiber-based sensor that enables the monitoring of high dose and high dose-rate environments, such as those encountered in high energy physics facilities or in the nuclear industry, by exploiting the near infrared (NIR) emission of interstitial oxygen molecules. 7 The infrared photoluminescence of O 2 enclosed in silica was investigated by several authors. [8][9][10] The interstitial molecular oxygen exhibits an emission band centered at 1272 nm (0.975 eV), excitable in the visible and NIR, arising from its first excited singlet state, with a Full Width at Half Maximum (FWHM) of $16 nm (0.011 eV) and decay time as long as $0.8 seconds for silica glasses with low-OH content.…”

“…[17][18][19] After the treatment, micro-Raman measurements were carried out with He-Cd probe laser excitation (operating at 442 nm) coupled with a confocal spectrometer LabRam Aramis (Jobin-Yvon) in order to verify the effectiveness of the loading procedure. 7 Fig. 1 shows the Raman spectrum of the F-O2 core sample.…”

“…This interesting property confirmed the potential of such components as sensors combining both sensitivity and longevity. 7 The experimental setup employed to study the iRL of the O 2 -loaded OFs consists of a NIR512 Ocean-Optics spectrometer and the Probix machine at CEA, generating a 10 keV X-rays beam (X-ray spectrum reported in Ref. 21, maximum dose-rate of 180 kGy(SiO 2 )/h, and a beam diameter of 2.5 cm).…”

“…The irradiation is expected to degrade the intensity of the iRL through at least two main processes: the radiation induced conversion of interstitial O 2 molecules into other types of defects (oxygen excess-related centers) and the RIA at 1272 nm. 7,23 To evaluate the total impact of these two effects, the fibers were irradiated at room temperature with a dose rate of 180 kGy/h for several hours until the total dose of 1 MGy was reached. In Fig.…”