Download or read book Improving the Materials Irradiation Xperimental Facility and Increasing Understanding of Helium Irradiation of Tungsten written by and published by . This book was released on 2013 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Minimizing damage to plasma facing components is a key issue that needs to be resolved before realizing commercial fusion reactors. The Materials Irradiation Experiment (MITE-E) at the University of Wisconsin Inertial Electrostatic Confinement (UW-IEC) Laboratory simulates fusion reactor conditions of light ion bombardment at high temperatures. Past experiments done in the MITE-E revealed that different morphologies developed on different grains of tungsten after irradiation with 30 keV helium ions at 900 oC. In this thesis, these structures have been correlated with the underlying crystal structure. Grains with orientations near {0 0 1} formed plateaus that were less eroded, while grains near {1 0 1} formed ripples parallel to 0 1 0. The connection of morphology to crystal orientation was made possible by the development of a new sample marking technique that allows the same location on a sample to be analyzed with the scanning electron microscope and the electron backscatter diffraction technique. It was also discovered that the sample pre-irradiation surface treatment has a large impact on the morphologies that develop after irradiation. A sample irradiated with helium ions over a spectrum of energies developed a more damaged surface structure than samples irradiated to the same fluence with mono-energetic helium. The sample with multiple energy implantation did not develop blisters, which had been seen previously on mono-energetically implanted samples in the MITE-E. In a separate experiment, samples of ZrB2, made with isotopically separated 11B, were irradiated with 30 keV helium ions in the MITE-E, and the results were compared to other materials irradiated under similar conditions. The rates and levels of damage observed on all samples would have a significant impact on fusion reactor divertor plates and first walls.