Nuclear Engineering Commons^™

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-Pérot 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, …