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CaF2

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Full-Text Articles in Nuclear Engineering

Examination Of Color Center Formation In Caf2 Crystals When Exposed To Gamma And Mixed Neutron/Gamma Fields, Sara M. Pelka Jul 2017

Examination Of Color Center Formation In Caf2 Crystals When Exposed To Gamma And Mixed Neutron/Gamma Fields, Sara M. Pelka

Nuclear Engineering ETDs

Color centers in CaF2 were studied in this work, in parallel with examinations of changes in the refractive index of the crystals by the larger research group, after they were subjected to radiation. Color centers induced by gamma rays and in mixed neutron-gamma fields were studied in CaF2 and LiF using transmittance and absorbance spectra. The goals were to examine both neutron and neutron-gamma mixed field irradiations to be able to isolate neutron only effects and to correlate these color center effects with refractive index effects studied by our larger collaboration. Irradiation sources include 137Cs, DD and ...


High Precision Refractive Index Measurement Techniques Applied To The Analysis Of Neutron Damage And Effects In Caf2 Crystals, Joseph P. Morris Ph.D. Jul 2017

High Precision Refractive Index Measurement Techniques Applied To The Analysis Of Neutron Damage And Effects In Caf2 Crystals, Joseph P. Morris Ph.D.

Nuclear Engineering ETDs

Neutron irradiation damages material by atomic displacements. The majority of these damage regions are microscopic and difficult to study, though they can cause a change in density and thus a change in refractive index in transparent materials. This work utilized CaF2 crystals to track refractive index change based on neutron radiation dose. High precision refractive index measurements were performed utilizing a nested-cavity mode-locked laser where the CaF2 crystal acted as a Fabry-PĂ©rot Etalon (FPE). By comparing the repetition rate of the cavity and the repetition rate of the FPE, refractive index change was determined. Following several irradiation experiments ...