NSUF 20-3085: Radiation-induced signal attenuation and drift of single crystal sapphire optical fiber sensors

This RTE will perform additional characterization of single crystal sapphire samples that were previously irradiated to fast neutron fluences on the order of 10^21 n/cm^2 at temperatures ranging from ~100 to 700 C in HFIR. The additional characterization will determine 1) whether the increased radiation-induced attenuation (RIA) of light transmission in α-Al2O3, after high neutron fluence irradiation at higher temperatures, is a real phenomenon that could limit in-pile applications for α-Al2O3 optical fiber-based sensors; or whether thermally-activated diffusion of impurities from surrounding materials could be responsible for the increased attenuation in α-Al2O3 at higher temperatures, and 2) the expected signal drift in α-Al2O3 fiber optic sensors due to radiation-induced swelling of single-crystal α-Al2O3 along the c-axis (the direction along which light propagates in the fiber). The measurements will be made after irradiation to higher neutron fluences over a broader temperature range compared to measurements from previous works. EDS measurements will be performed to determine impurity concentrations, XRD will be used to determine lattice parameter swelling, and FIB + TEM will provide size and density distributions of voids and dislocation loops to inform the lattice parameter measurements. The results will inform instrumented irradiation tests of spatially distributed sapphire optical fiber based temperature sensors being performed under a current NEET funded activity.

추가 정보

필드	값
Abstract	This RTE will perform additional characterization of single crystal sapphire samples that were previously irradiated to fast neutron fluences on the order of 10^21 n/cm^2 at temperatures ranging from ~100 to 700 C in HFIR. The additional characterization will determine 1) whether the increased radiation-induced attenuation (RIA) of light transmission in α-Al2O3, after high neutron fluence irradiation at higher temperatures, is a real phenomenon that could limit in-pile applications for α-Al2O3 optical fiber-based sensors; or whether thermally-activated diffusion of impurities from surrounding materials could be responsible for the increased attenuation in α-Al2O3 at higher temperatures, and 2) the expected signal drift in α-Al2O3 fiber optic sensors due to radiation-induced swelling of single-crystal α-Al2O3 along the c-axis (the direction along which light propagates in the fiber). The measurements will be made after irradiation to higher neutron fluences over a broader temperature range compared to measurements from previous works. EDS measurements will be performed to determine impurity concentrations, XRD will be used to determine lattice parameter swelling, and FIB + TEM will provide size and density distributions of voids and dislocation loops to inform the lattice parameter measurements. The results will inform instrumented irradiation tests of spatially distributed sapphire optical fiber based temperature sensors being performed under a current NEET funded activity.
Award Announced Date	2020-07-14T14:00:43.6
Awarded Institution	Idaho National Laboratory
Facility	Advanced Test Reactor
Facility Tech Lead	Alina Zackrone, Kory Linton
Irradiation Facility	None
PI	Christian Petrie
PI Email	[email protected]
Project Type	RTE
RTE Number	3085