2018 | ANNUAL REPORT 79 Figure 3. Disassembly of Fire Rabbit at the Irradiated Materials Examination and Testing Laboratory following neutron irradiation in the High Flux Isotope Reactor. Top left: a hot-cell operator opening the capsule; top right: capsule housing being carefully milled to retrieve the delicate samples; bottom: retrieved specimens with aluminum thermal homogenizer jacket (left), SiC/ SiC composite tube with centering thimbles (middle), and monolithic SiC tube (right). The capsules were irradiated in the FluxTrap facility of the High Flux Isotope Reactor for one full cycle following approval of the entirely new capsule design for the reactor. During this irradiation, the SiC sample accumulated the damage level of ~2 displacement per atom, achieving the swelling-saturation dose.The irradiated capsules were then carefully opened using a precision milling tool in the Irradiated Materials Examina- tion andTesting Laboratory.The capsule-opening operation, including the capsule being milled while gently clamped in fixture, and the specimens being successfully retrieved are shown in Figure 3 Verifying the actual temperature of irradiation is essential for this experi- ment because the temperature profile defines stress distribution within each specimen. Sources of potential deviations from design temperature include poor thermal contact at any interface between the specimen and the housing, poor specimen quality, and unexpected axial heat loss from the heating tube. Passive temperature monitors were used to verify the temperature of the heating tube, and the average irradiation temperatures of individual specimens were confirmed by swelling measurements.