[en] Transmission electron microscopy (TEM) studies of ion-implanted samples require one-sided thinning in order for the implanted surface to be examined. The purpose of this report is to describe techniques for thinning Fe and Al which have been optimized to reproducibly obtain samples with maximum electron-transparent thin area

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[en] Transmission electron diffraction was used to identify the phases present before and after irradiating multiple layers of vapor deposited Al and Sb with 400 keV Xe⁺ ions. Films were examined prior to irradiation and fcc Al and hexagonal Sb were identified. Xe irradiation at 80 K and 475 K causes the majority of the Al and Sb to react and form the compound AlSb. However, at 295 K, most of the initial phases remain unreacted even after irradiation to fluences of 2.4 x 10¹⁶ Xe/cm². During this study four phases were identified: fcc Al, hexagonal Sb, cubic AlSb, and cubic NaCl from the NaCl substrate used to deposit the films upon. The electron diffraction results for these phases are compared with x-ray diffraction results, and are tabulated for future analyses

[en] A technique has been developed for cleaning and conditioning low- and medium-energy accelerators by alternating a glow discharge using hydrogen gas and a glow discharge using oxygen gas. The study was initiated using a 2.5-MeV Van de Graaff accelerator. It has since been used on both lower-energy (down to 10 keV) and higher-energy (up to 10 MeV) accelerators with equal effectiveness. In the development stage, the conditioning time for attaining the nominal maximum voltage was reduced from about ten days using pumping and voltage conditioning to one day using the glow discharge technique. After a glow discharge conditioning sequence, the 2.5-MeV accelerator could be operated effectively at energies to 3.4 MeV. In addition, the accelerator tube life was found to increase significantly over the expected lifetime. This technique is described and safety considerations are discussed

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[en] Cermet coatings consisting of silicon carbide (SiC) particles in an aluminum matrix have been produced by a low-pressure chamber plasma spray process. Properties of these coatings are being investigated to evaluate their suitability for use in next generation magnetic confinement fusion reactors. Although this preliminary study has focused primarily upon SiC/Al cermets, the deposition process can be adapted to other ceramic/metal combinations. Potential applications for cermet coatings in magnetic fusion devices are presented along with experimental results from thermal tests of candidate coatings

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[en] This paper discusses the thermal response of two prototypical International Thermonuclear Experimental Reactor (ITER) divertor channels during simulated loss-of-flow-accident (LOFA) experiments. The thermal response was characterized by the time-to-burnout (TBO), which is a figure of merit on the mockups' survivability. Data from the LOFA experiments illustrate that (a) the pre-LOFA inlet velocity does not significantly influence the TBO, (b) the incident heat flux (IHF) does influence the TBO, and (c) a swirl tape insert significantly improves the TBO and promotes the initiation of natural circulation. This natural circulation enabled the mockup to absorb steady-state IHFs after the coolant circulation pump was disabled. Several methodologies for thermal-hydraulic modeling of the LOFA were attempted

[en] The Electron Beam Test System was successfully modified to deposit power densities in the range of 100's kW/cm² for a few milliseconds on an area of 0.1 cm². This modification was made in response to a need for an experimental apparatus that could provide intense power deposition on a short time scale. Modifications to computer software and the electron gun electronics were necessary to provide a versatile method of moving and focusing the electron beam on a millisecond time scale. The resulting beam operation was demonstrated to provide the necessary parameters in a reproducible fashion. It was shown that an infrared camera could be used to provide measurements of the surface temperature during an energy deposition of only a few milliseconds. The correlation of the vaporization and melting of the target material with the energy deposition or surface temperature during events such as plasma disruptions or arcing is possible