- June 2019
International Standard Serial Number (ISSN)
- The aim of this proposal is to perform microstructural characterization at the nanoscale on neutron irradiated 14YWT by combining the capabilities of transmission electron microscopy (TEM) and atom probe tomography (APT) techniques. The samples of interest are TEM disks of 14YWT (SM13 heat) that have been neutron irradiated in the BOR-60 reactor, in Russia, at 16.6 dpa and at temperatures 386C (capsule P027) and 412C (capsule P033). Two TEM disks from each irradiation condition are currently stored in the Low Activation Materials Development and Analysis facility in Oak Ridge National Laboratory (LAMDA, ORNL). Access to the focused ion beam (FIB) instruments (FEI Quanta 3D Dual Beam FIB-SEM and FEI Versa 3D Dual Beam FEG FIB-SEM) in the LAMDA facility is required to prepare 4 lift-out cantilevers (2 from each irradiation condition) for TEM and APT analysis. Transmission Kikuchi Diffraction (tKD) will also be performed in the FEI Versa 3D Dual Beam FEG FIB-SEM. The TEM samples will be characterized using the FEI Talos 200X scanning/transmission electron microscope (S/TEM) with SuperX energy-dispersive spectroscopy (EDS) detector and the JEOL JEM-2100F S/TEM with EDS detector and Gatan Quantum Image Filter within the LAMDA facility at ORNL. First steps of APT sample preparation will be performed using the FIB at LAMDA, and the samples will be shipped to the Materials Research Facility in the Culham Centre for Fusion Energy (CCFE) in Oxford, in which a final milling process to reach the suitable shape for APT will be performed. The potential activity of the nanometric volumes involved in the final stage will be under any detection limit, and then the samples will be transferred to the Department of Materials-University of Oxford, in which atom probe tomography experiments will be carried out using a CAMECA LEAP5000 instrument.