skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Testing of Sapphire Optical Fiber and Sensors in Intense Radiation Fields When Subjected to Very High Temperatures

Abstract

The primary objective of this project was to determine the optical attenuation and signal degradation of sapphire optical fibers & sensors (temperature & strain), in-situ, operating at temperatures up to 1500°C during reactor irradiation through experiments and modeling. The results will determine the feasibility of extending sapphire optical fiber-based instrumentation to extremely high temperature radiation environments. This research will pave the way for future testing of sapphire optical fibers and fiber-based sensors under conditions expected in advanced high temperature reactors.

Authors:
 [1];  [1]
  1. The Ohio State Univ., Columbus, OH (United States)
Publication Date:
Research Org.:
Battelle Energy Alliance, LLC, Idaho Falls, ID (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1416357
Report Number(s):
12-3456
12-3456
DOE Contract Number:
AC07-05ID14517
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English

Citation Formats

Blue, Thomas, and Windl, Wolfgang. Testing of Sapphire Optical Fiber and Sensors in Intense Radiation Fields When Subjected to Very High Temperatures. United States: N. p., 2017. Web. doi:10.2172/1416357.
Blue, Thomas, & Windl, Wolfgang. Testing of Sapphire Optical Fiber and Sensors in Intense Radiation Fields When Subjected to Very High Temperatures. United States. doi:10.2172/1416357.
Blue, Thomas, and Windl, Wolfgang. 2017. "Testing of Sapphire Optical Fiber and Sensors in Intense Radiation Fields When Subjected to Very High Temperatures". United States. doi:10.2172/1416357. https://www.osti.gov/servlets/purl/1416357.
@article{osti_1416357,
title = {Testing of Sapphire Optical Fiber and Sensors in Intense Radiation Fields When Subjected to Very High Temperatures},
author = {Blue, Thomas and Windl, Wolfgang},
abstractNote = {The primary objective of this project was to determine the optical attenuation and signal degradation of sapphire optical fibers & sensors (temperature & strain), in-situ, operating at temperatures up to 1500°C during reactor irradiation through experiments and modeling. The results will determine the feasibility of extending sapphire optical fiber-based instrumentation to extremely high temperature radiation environments. This research will pave the way for future testing of sapphire optical fibers and fiber-based sensors under conditions expected in advanced high temperature reactors.},
doi = {10.2172/1416357},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2017,
month =
}

Technical Report:

Save / Share:
  • The primary objective of this project is to measure and model the performance of optical fibers in intense radiation fields when subjected to very high temperatures. This research will pave the way for fiber optic and optically based sensors under conditions expected in future high-temperature gas-cooled reactors. Sensor life and signal-to-noise ratios are susceptible to attenuation of the light signal due to scattering and absorbance in the fibers. This project will provide an experimental and theoretical study of the darkening of optical fibers in high-radiation and high-temperature environments. Although optical fibers have been studied for moderate radiation fluence and fluxmore » levels, the results of irradiation at very high temperatures have not been published for extended in-core exposures. Several previous multi-scale modeling efforts have studied irradiation effects on the mechanical properties of materials. However, model-based prediction of irradiation-induced changes in silica's optical transport properties has only recently started to receive attention due to possible applications as optical transmission components in fusion reactors. Nearly all damage-modeling studies have been performed in the molecular-dynamics domain, limited to very short times and small systems. Extended-time modeling, however, is crucial to predicting the long-term effects of irradiation at high temperatures, since the experimental testing may not encompass the displacement rate that the fibers will encounter if they are deployed in the VHTR. The project team will pursue such extended-time modeling, including the effects of the ambient and recrystallization. The process will be based on kinetic MC modeling using the concept of amorphous material consisting of building blocks of defect-pairs or clusters, which has been successfully applied to kinetic modeling in amorphized and recrystallized silicon. Using this procedure, the team will model compensation for rate effects, and the interplay of rate effects with the effects of annealing, to accurately predict the fibers' reliability and expected lifetime« less
  • This is the final report for the program “Micro-Structured Sapphire Fiber Sensors for Simultaneous Measurements of High Temperature and Dynamic Gas Pressure in Harsh Environments”, funded by NETL, and performed by Missouri University of Science and Technology, Clemson University and University of Cincinnati from October 1, 2009 to September 30, 2014. Securing a sustainable energy economy by developing affordable and clean energy from coal and other fossil fuels is a central element to the mission of The U.S. Department of Energy’s (DOE) National Energy Technology Laboratory (NETL). To further this mission, NETL funds research and development of novel sensor technologiesmore » that can function under the extreme operating conditions often found in advanced power systems. The main objective of this research program is to conduct fundamental and applied research that will lead to successful development and demonstration of robust, multiplexed, microstructured silica and single-crystal sapphire fiber sensors to be deployed into the hot zones of advanced power and fuel systems for simultaneous measurements of high temperature and gas pressure. The specific objectives of this research program include: 1) Design, fabrication and demonstration of multiplexed, robust silica and sapphire fiber temperature and dynamic gas pressure sensors that can survive and maintain fully operational in high-temperature harsh environments. 2) Development and demonstration of a novel method to demodulate the multiplexed interferograms for simultaneous measurements of temperature and gas pressure in harsh environments. 3) Development and demonstration of novel sapphire fiber cladding and low numerical aperture (NA) excitation techniques to assure high signal integrity and sensor robustness.« less
  • This document lists the requirements for the fiber optic mechanical shock sensor for the Los Alamos HERT (High Explosive Radio Telemetry) project and provides detailed process steps for fabricating, testing, and assembling the fiber shock sensors for delivery to Los Alamos.
  • The motivation for the search for in-line instruments for pH and coolant oxidizing power, also known as redox potential or Eh, lies in the relationship between these quantities and corrosion damage to components containing high-temperature high-pressure water. These quantities can be readily measured by currently available probes if the coolant is cooled to room temperature. However, the corrosive nature of water changes dramatically between room temperature and full power plant operating temperatures (300{degree}C), and the relationship between pH and Eh measured at room temperature and pH and Eh measured at high temperature is a function of the impurities in ormore » the additives in the water. Furthermore, an in-line instrument would preclude the need for cooling samples prior to their measurement. In this report, the results of research on high-temperature optical-fiber pH sensors will be presented. We have shown that these sensors (optrodes) can be made to work in very-high-temperature (300{degree}C) water for long periods and that it is possible to measure pH using fluorescent inorganic ions doped into solid matrices. A high-temperature pH optrode can be made using these techniques; however, more research is needed into the chemistry of the carrier matrices and fluorescent dopants. New types of materials should be studied, including solid polymer ionic conductors and high-temperature epoxies. Particular emphasis should be placed on developing an Eh optrode because it also will be very useful and probably more easily developed. Transition-metal ions and complexes, as well as certain stable organic dyes, (materials that are very stable at high temperature) should also be investigated as dopants.« less
  • The goal of this program was the development of an optical pH measurement system capable of operating in a high-temperature aqueous environment. This project built upon a dual-wavelength fiber optic sensing system previously developed by Research International which utilizes light-emitting diodes as light sources and provides remote absorption spectroscopy via a single bidirectional optical fiber. Suitable materials for constructing an optical pH sensing element were identified during the program. These included a sapphire/Ti/Pt/Au thin-film reflector, quartz and sapphire waveguides, a poly(benzimidazole) matrix, and an azo chromophore indicator. By a suitable combination of these design elements, it appears possible to opticallymore » measure pH in aqueous systems up to a temperature of about 150{degrees}C. A pH sensing system capable of operating in high-purity, low-conductivity water was built using quasi-evanescent wave sensing techniques. The sensing element incorporated a novel, mixed cellulose/cellulose acetate waveguide to which an azo indicator was bound. Testing revealed that the system could reproducibly respond to pH changes arising from 1 ppm differences in the morpholine content of low-conductivity water without influencing the measurement. The sensing system was stable for 150 hrs at room temperature, and no loss or degradation of the pH-responsive optical indicator was seen in 160 hrs at 50{degrees}C. However, the prototype polymer waveguide lost transparency at 1.7% per day during this same 50{degrees}C test. Additional effort is warranted in the areas of water-compatible waveguides and evanescent-wave detection methods.« less