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Results for “VAPORIZATION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Vapor phase deposition of alumina on interior surfaces of tritium storage containers

Efficient tritium management and containment are critical challenges for nuclear fusion. To mitigate issues related to permeation into structural materials and isotopic exchange with protium, permeation barriers must be applied to the nonplanar internal surfaces of tritium handling components. In this study, we developed an atomic layer deposition (ALD) system to deposit films on canisters used to store and transport tritium. Growth conditions for deposition of Al 2 O 3 were mapped spatially along the length of a canister using silicon witness samples characterized by ellipsometry, atomic force microscopy, and x-ray reflectivity (XRR). We identified ALD process windows for growth at temperatures between 100 and 140 °C. Furthermore, we compared films grown on our Si witness samples to those grown on polished stainless steel 316 (SS316). X-ray photoelectron spectroscopy indicates two distinct chemical states for the alumina, while XRR confirms that the overall growth rate is similar to the 1.1 Å/cycle that we observed on the Si witness samples.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2026

Supporting Data for "Pitfalls in Parameters: Practical Process Development in Chemical Vapor Processing of SiC"

CALculation of PHAse Diagrams (CALPHAD) was used to produce equilibrium phase diagrams of the MTS/H2 system. These were calculated in FactSage 8.2 using a combination of the FactPS and SGTE Solutions 2022 databases. Equilibrium was calculated for 185 gas species, 36 pure liquids, 8 pure solids, 1 liquid solution, and 22 solid solutions. Phase diagrams were calculated with 25 °C steps in temperature from 700 to 1325 °C and 10 torr steps in pressure from 20 to 760 torr.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Height-resolved emission spectroscopy and high-speed imaging of the TiAl6V4 vapor plume under laser powder bed fusion conditions

Optical emission spectroscopy is increasingly used as an in situ monitoring technique during laser powder bed fusion (LPBF) because plume emission holds elemental information not found in other in situ sensing techniques. This work explores the shape, stability, and temperature of the emission plume above the melt pool of Ti6Al4 V undergoing laser scans under LPBF-like processing conditions, using high-speed video and height-resolved spectroscopy to study the details of plume dynamics. Optical emission spectroscopy is conducted in the 480 nm to 525 nm region, where Ti emission is strong, with 0.3 mm vertical resolution above the baseplate. The Boltzmann plot method is used to determine temperature at each probed elevation, which indicates that the hottest location of the plume is occasionally elevated 0.3 mm to 0.6 mm above the scanning surface. The results show that the plume shape, stability, temperature, and spectra are highly dependent on the processing conditions. We highlight some of the complexities of optical emission spectroscopy and discuss potential challenges for implementing optical emission spectroscopy across an entire build.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Electron-induced chemical transformation of vapor-phase synthesized hybrid resist materials for EUV and beyond EUV lithography

Here, in this study, we utilize an in situ Fourier transform infrared (FTIR) spectroscopy chamber equipped with an electron flood gun to comprehensively investigate the electron-induced chemical transformations in advanced inorganic–organic hybrid resist thin films. The characteristics of the electron gun were assessed, showing a detectable current decrease with increasing Faraday cup bias voltage, confirming that the electron energies impacting the sample were within the expected range. This unique FTIR system was applied to study two hybrid resist thin-film systems, Al–HQ and Zn–HQ, both exhibiting saturation growth characteristics at 150 °C. Results revealed that Al–HQ demonstrated superior electron sensitivity compared to Zn–HQ at energies ≤ 100 eV. Chemical changes observed were consistent with previous findings, underscoring the potential of this methodology to elucidate exposure mechanisms. This research contributes to the fundamental understanding necessary for the development of advanced resist materials for the next-generation nanolithography applications.

36 MATERIALS SCIENCE↗