Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Tm”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Tm(CuS)2 by Materials Project

Tm(CuS)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Tm is bonded to six equivalent S atoms to form distorted edge-sharing TmS6 octahedra. All Tm–S bond lengths are 2.80 Å. Cu is bonded in a 4-coordinate geometry to four equivalent S atoms. There are three shorter (2.32 Å) and one longer (2.51 Å) Cu–S bond lengths. S is bonded in a 7-coordinate geometry to three equivalent Tm and four equivalent Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(Ni2As)2 by Materials Project

Tm(Ni2As)2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Tm is bonded to six equivalent As atoms to form a mixture of distorted edge and corner-sharing TmAs6 octahedra. The corner-sharing octahedral tilt angles are 41°. There are two shorter (2.88 Å) and four longer (2.90 Å) Tm–As bond lengths. Ni is bonded in a 3-coordinate geometry to three equivalent As atoms. All Ni–As bond lengths are 2.39 Å. As is bonded in a 9-coordinate geometry to three equivalent Tm and six equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Optical coherence and energy-level properties of a Tm 3+ -doped LiNbO 3 waveguide at subKelvin temperatures

We characterize the optical coherence and energy-level properties of the 795-nm 3 H 6 to 3 H 4 transition of Tm 3+ in a Ti 4+ :LiNbO 3 waveguide at temperatures as low as 0.65 K. Coherence properties are measured with varied temperature, magnetic field, optical excitation power and wavelength, and measurement timescale. We also investigate nuclear spin-induced hyperfine structure and population dynamics with varying magnetic field and laser excitation power. Except for accountable differences due to different Ti 4+ - and Tm 3+ -doping concentrations, we find that the properties of Tm 3+ :Ti 4+ :LiNbO 3 produced by indiffusion doping are consistent with those of a bulk-doped Tm 3+ :LiNbO 3 crystal measured under similar conditions. Furthermore, our results, which complement previous work in a narrower parameter space, support using rare-earth ions for integrated optical and quantum signal processing.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2020

Treatment of Problematic Reactive Metal Wastes Using the GeoMelt{sup R} In-Container Vitrification (ICV{sup TM}) Process - 20326

Decommissioning of sodium-cooled reactors and fast reactor technologies has generated a number of reactive metal waste configurations that are problematic to treat and typically lack cost effective treatment methods and disposition options. As a result, Veolia Nuclear Solutions, under contract with Idaho National Laboratory (owned by the U.S. Department of Energy and managed and operated by Battelle Energy Alliance, LLC) demonstrated its GeoMelt{sup R} In-Container Vitrification (ICV){sup TM} technology to safely convert sodium metal to a non-reactive vitrified oxide form. The demonstration project, supported by glass formulation and crucible testing, consisted of a series of ICV{sup TM} melts that processed elemental sodium into stable non-reactive glass. INL is currently implementing GeoMelt{sup R} technology as a means to safely and reliably convert radioactive reactive metal residues that contaminate sodium cooled reactor components into waste forms that comply with existing disposition pathways. Reactive metal wastes require treatment in order to remove the Resource Conservation and Recovery Act (RCRA) reactivity and ignitability characteristics to comply with land disposal restrictions. GeoMelt{sup R}, which is an alternative to other potential treatment approaches, provides a robust approach that chemically converts the reactive metals to an inert oxide while also immobilizing radionuclides in a vitrified waste form with durability equal to or better than vitrified nuclear fuel reprocessing wastes (very robust and inert waste forms). Most other treatment approaches generate hydrogen gas which is problematic. In 2016, Veolia Nuclear Solutions first demonstrated the effectiveness of the GeoMelt{sup R} ICV{sup TM} process in deactivating reactive sodium metal. Crucible, bench-scale, and engineering-scale demonstrations were conducted on several surrogate waste configurations with various ratios of sodium metal and glass formers. Each ratio and configuration demonstrated complete deactivation of the surrogate sodium metal. Follow-on work in 2017 demonstrated the deactivation of reactive sodium by GeoMelt{sup R} ICV{sup TM} at a higher waste loading relative to previously demonstrated work performed in 2016; the higher waste loading optimized glass chemistry while enhancing the economical full-scale treatment of reactive metals. Additionally, follow-on demonstration testing in 2018 and 2019 focused on more complex shapes and other reactive-metals (mocked up Experimental Breeder Reactor II [EBR-II] subassembly, sodium filled heat exchanger, and a can containing sodium potassium alloy) which were all performed at engineering scale. Veolia Nuclear Solutions designed, installed, and commissioned in September 2018, at Perma-Fix Northwest in Richland Washington, a 10-metric ton full-scale GeoMelt unit (GeoMelt{sup R} Richland) for the treatment of reactive metal wastes. As of September 2019, over 900 55-gallon drums containing a total of around 3,500 lb of sodium with low levels of radioactivity have been treated at GeoMelt{sup R} Richland, with resulting glass monoliths disposed at the Nevada National Security Site (NNSS). A full-scale radiological demonstration melt on an actual EBR-II subassembly has also been performed using the full-scale melter in 2019. The GeoMelt{sup R} technology is a proven radioactive waste treatment technology capable of immobilizing radioactive wastes, including bulk rubble such as drums and other steel vessels usually without pretreatment. Utilizing the GeoMelt{sup R} technology to treat reactive metals eliminates pretreatment steps resulting from having to separate the reactive metal from steel containers or jackets as GeoMelt{sup R} can easily operate at temperatures sufficient to melt the steel and expose the reactive metal for treatment. Eliminating handling steps of reactive metals is a significant safety advantage since reactive metals are pyrophoric. The results generated as a part of the 2018-2019 demonstration program are presented in the paper. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Materials Data on Tm(HO)3 by Materials Project

Tm(HO)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one Tm(HO)3 sheet oriented in the (1, 0, 0) direction. Tm3+ is bonded to six O2- atoms to form edge-sharing TmO6 octahedra. There are a spread of Tm–O bond distances ranging from 2.22–2.27 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Tm3+ and one H1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Tm3+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Tm3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(PO)2 by Materials Project

Tm(PO)2 crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of eight Tm(PO)2 clusters. Tm3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Tm–O bond lengths are 2.17 Å. P+0.50+ is bonded in a single-bond geometry to one O2- atom. The P–O bond length is 1.58 Å. O2- is bonded in a water-like geometry to one Tm3+ and one P+0.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(NO3)3 by Materials Project

Tm(NO3)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one Tm(NO3)3 sheet oriented in the (0, 0, 1) direction. Tm3+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Tm–O bond distances ranging from 2.32–2.81 Å. There are three inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the third N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.23–1.32 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Tm3+ and one N5+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Tm3+ and one N5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Tm3+ and one N5+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Tm3+ and one N5+ atom. In the fifth O2- site, O2- is bonded in a distorted L-shaped geometry to one Tm3+ and one N5+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one Tm3+ and one N5+ atom. In the seventh O2- site, O2- is bonded in a distorted L-shaped geometry to one Tm3+ and one N5+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Tm3+ and one N5+ atom. In the ninth O2- site, O2- is bonded in a distorted L-shaped geometry to one Tm3+ and one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(AsO)2 by Materials Project

Tm(AsO)2 crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of eight Tm(AsO)2 clusters. Tm3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Tm–O bond lengths are 2.10 Å. As+0.50+ is bonded in a single-bond geometry to one O2- atom. The As–O bond length is 1.76 Å. O2- is bonded in a bent 150 degrees geometry to one Tm3+ and one As+0.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(Fe2Ge)2 by Materials Project

TmFe4Ge2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Tm is bonded to six equivalent Ge atoms to form a mixture of distorted edge and corner-sharing TmGe6 octahedra. The corner-sharing octahedral tilt angles are 41°. There are two shorter (2.91 Å) and four longer (2.94 Å) Tm–Ge bond lengths. Fe is bonded in a 3-coordinate geometry to three equivalent Ge atoms. There are one shorter (2.43 Å) and two longer (2.44 Å) Fe–Ge bond lengths. Ge is bonded in a 9-coordinate geometry to three equivalent Tm and six equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

RAMM-TM for detection of gas leakage from canisters containing spent nuclear fuel

Remote Area Modular Monitoring (RAMM) for canister surface temperature measurement (TM), or RAMM-TM, is a novel remote monitoring device for detection of gas leakage based on surface temperature measurements of canisters containing spent nuclear fuel. Here we describe the development of RAMM-TM, as is the demonstration of its performance in detecting canister gas leakage from a small, simulated chloride-induced stress corrosion crack in experiments using a 1/4.5-scale model cask. Both helium and air gas leakage from a canister were detected within hours after the start of the leakage. The change in surface temperatures at the top and bottom of the canister (ΔTBT) during gas leakage (depressurization) triggered automatic alarms, providing a sound basis for early detection of gas leakage from the canister. This methodology would allow consequence management through the implementation of mitigatory actions to continue effective aging management and to reduce risks to public safety, health, and the environment.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Unraveling Site Selective Magnetic Properties of Cobalt Sites in Critical Elements Lean RE(TM)5 Magnet Materials

We report here our discovery of crystallographic and interstitial sites and onsite electron correlation propelled intrinsic and derived permanent magnetic properties of critical elements lean RE(TM) 5 (RE = La, Ce and TM = Fe, Co) magnet materials. A full potential linearized augmented plane wave (FP-LAPW) method within the local density approximation (LDA) is used to investigate and analyze the electronic structure and magnetism of these RE(TM) 5 type structures. To better correlate the experimental results, the effective Coulomb (U) and exchange (J) interactions (Hubbard parameters) are crucial at the transition metal sites. Results show that the main propeller of magnetic anisotropy in these compounds is the cobalt atoms at the 2c sites not the 3g sites. This site-specific property and site preference energetics are used to replace 3g sites with non-critical elements such as iron that exhibits a larger magnetic moment. Based on this strategic replacement, we predict two new compounds that have a larger hardness parameter with a relatively large energy product due to the atomic dilution caused by interstitial addition of nitrogen in the compounds: CeCo 2 Fe 3 N 2 and LaCo 2 Fe 3 N 2 .

Rare-earths↗
DOE OSTI2021

Preparation of defect-free asymmetric gas separation membranes with dihydrolevoglucosenone (Cyrene TM ) as a greener polar aprotic solvent

Nonsolvent-induced phase separation (NIPS) is widely used to prepare asymmetric gas separation membranes. Most industrial NIPS casting solution formulations are limited to a small group of glassy polymers and, importantly, require toxic polar aprotic solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), or N-methyl-2-pyrrolidone (NMP). Growing restrictions on the use of such solvents are spurring the search for more benign casting solution formulations that do not compromise membrane performance. Herein this study reports high-flux, defect-free asymmetric polysulfone (PSf) gas separation membranes prepared using dihydrolevoglucosenone (Cyrene TM ), a polar aprotic solvent that is believed to be safer than DMAc, DMF, and NMP, as the majority casting solution component. Optimized formulations and casting conditions produce membranes with hydrogen permeances exceeding 100 gas permeance units (GPU) and selectivities at or above those of dense PSf films. Dry/wet NIPS membrane performance improved with shorter dry step times and increased Cyrene TM loadings relative to the volatile solvent, tetrahydrofuran (THF), in the casting solution. The high water-Cyrene TM Flory-Huggins interaction parameter, $\mathcal{X}12$ , and high casting solution viscosities help suppress the formation of skin layer defects and sublayer macrovoids. In some cases, membrane selectivities were influenced by substructure resistance, providing insight into the relationship between sublayer morphology and membrane performance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Fabrication of Tantalum and Hafnium Carbide Fibers via Forcespinning TM for Ultrahigh‐Temperature Applications

In this work, a novel method for producing ultrafine tantalum and hafnium carbide fibers using the Forcespinning TM technique via a nonhalide‐based sol‐gel process was investigated. An optimal solution viscosity range was systematically determined via rheological studies of neat PAN/DMF as a function of fiber formation. Subsequently, Forcespinning TM parameters were also systemically studied to determine the optimal rotational velocity and spinneret‐to‐collecting rod distance required for ideal fiber formation. TaC and HfC fibers were synthesized via Forcespinning TM utilizing a mixture of PAN and refractory transition metal alkoxides (i.e., tantalum (V) ethoxide and hafnium (IV) tert‐butoxide) in DMF solution based on optimal conditions determined from the neat PAN/DMF. In all instances after calcination, powder X‐ray diffraction (PXRD) and energy dispersive spectroscopy (EDS) indicated that TaC and HfC fibers were produced. TGA/DSC confirmed the chemical stability of the resulting fibers.

Lee, Harold O.↗
DOE OSTI2026

Demonstration of thermal fracture limits of gas-cooled Nd:APG-1 and Tm:YLF slabs

High-energy short-pulse laser systems demonstrated to date have been limited to low repetition rates due to significant thermal management challenges associated with scaling these systems to high average power, including the need to understand the thermal fracture limits of laser gain media. In this paper, we demonstrate the thermal fracture limits of two high-average-power gain media in a realistic diode-pumped amplifier geometry: a 5 mm thick Nd:APG-1 slab and a 2 mm thick Tm:YLF slab, both cooled by room-temperature helium gas. Finite element analysis revealed maximum tensile stress at fracture of 25 ± 3 MPa for Nd:APG-1 and 30 ± 3 MPa for Tm:YLF. These stress levels correspond to average volumetric heat loads of 13 ± 1 W/cm 3 in Nd:APG-1 and 247 ± 12 W/cm 3 in Tm:YLF. Additional simulations show geometric scaling: thinner slabs tolerate higher heat loads before fracture, while larger pump spots reach the fracture stress at lower heat loads.

Lasers↗
DOE OSTI2020

Electrolytically Assisted Surface Decontamination (EASD{sup TM}) for POCO Operations - 20282

NNL in collaboration with C-Tech Innovation Ltd and Sellafield Ltd has been exploring innovative technologies to enable a significant reduction of radiological hazards within facilities during the Post Operational Clean Out (POCO) phase of a nuclear plant's life cycle. Reducing the hazard by effectively decontaminating plants in-situ during POCO delivers huge cost reductions for future decommissioning operations. These cost reduction benefits are realized by reducing the number and complexity of remote operations as well as lowering the long-term waste disposal costs. Whilst chemical decontamination can achieve the desired level of decontamination, applying aggressive chemical reagents is hazardous, potentially difficult to control and requires there to be complimentary effluent treatment and waste routes. This work has aimed to develop flexible and controllable decontamination processes which could be operated without the additional complexity and issues associated with chemical decontamination. The processes needed to be relatively fast and effective to minimize the time operators would spend in an active area. In addition, there was a driver to produce decontamination methodologies which generated a secondary waste compatible with current routes and which takes advantage of current waste capacity. The strategy therefore was to come up with a solution that works with, rather than against, the science and engineering behind process plants at Sellafield. Electrolytically Assisted Surface Decontamination (EASD{sup TM}) is an innovative electrochemical decontamination process (developed by NNL and C-Tech Innovation Ltd) that can remove activity from contaminated metal in very short time periods. Application of the patented electric waveform to the surface when treating contaminated metal with nitric acid has been shown to significantly enhance the decontamination performance. When compared to proposed baseline washout procedures at Sellafield, the only change to the process is the applied electrical waveform which is temporary and controllable. The current causes dissolution of the metal surface being decontaminated which leads to activity transferring from the plant item into the nitric acid effluent stream. This innovation has the potential to transform the POCO process and allow a nitric acid based washout approach to deliver POCO quickly and cost effectively within the existing infrastructure. Several devices have now been designed that incorporate this EASD{sup TM} technology and enable the decontamination process to be applied to a range items commonly identified as being contaminated during nuclear decommissioning programmes such as pipework, tanks and hotspots of walls/floors. Inactive and active laboratory-scale testing has been completed using both simulated and 'real-life' contaminated (low level waste) metallic items retrieved from different nuclear sites. Active trials demonstrated that contaminated items could be treated to free release levels within minutes. Engineering scale tests are currently being performed, with guidance from Sellafield's system engineers and plant managers, to provide the necessary re-assurance the designed devices could be successfully deployed in an on-plant scenario. The final stage of this development work is to carry out an active demonstration of the decontamination technology on Thorp at Sellafield. This paper aims to highlight progress made to date with the EASD{sup TM} technology and, more specifically, the development of an in-situ decontamination device for deployment within radioactive pipework. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Materials Data on Tm(SiNi)2 by Materials Project

Tm(NiSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Tm–Si bond lengths are 3.03 Å. Ni+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of corner and edge-sharing NiSi4 tetrahedra. All Ni–Si bond lengths are 2.29 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Tm3+, four equivalent Ni+2.50+, and one Si4- atom. The Si–Si bond length is 2.38 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(NiP)2 by Materials Project

Tm(NiP)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm3+ is bonded in a distorted body-centered cubic geometry to eight equivalent P3- atoms. All Tm–P bond lengths are 2.95 Å. Ni+1.50+ is bonded to four equivalent P3- atoms to form a mixture of edge and corner-sharing NiP4 tetrahedra. All Ni–P bond lengths are 2.26 Å. P3- is bonded in a 9-coordinate geometry to four equivalent Tm3+, four equivalent Ni+1.50+, and one P3- atom. The P–P bond length is 2.27 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(SiOs)2 by Materials Project

Tm(OsSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Tm3+ is bonded to eight equivalent Os+1.50- atoms to form distorted edge-sharing TmOs8 hexagonal bipyramids. All Tm–Os bond lengths are 3.17 Å. Os+1.50- is bonded in a 4-coordinate geometry to four equivalent Tm3+ and four equivalent Si atoms. All Os–Si bond lengths are 2.39 Å. Si is bonded in a 5-coordinate geometry to four equivalent Os+1.50- and one Si atom. The Si–Si bond length is 2.44 Å.

36 MATERIALS SCIENCE↗