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(ScF3)2N2(NF)4F2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one ammonia molecule, one hydrofluoric acid molecule, two monofluoroamine molecules, and one scandium fluoride molecule.
A mainstay pump for tritium systems, the Normetex scroll pump, is currently unavailable because the Normetex company went out of business. This pump was an all-metal scroll pump that served tritium processing facilities very well. Current tritium system operators are evaluating replacement pumps for the Normetex pump and for general used in tritium service. An all-metal equivalent alternative to the Normetex pump has not yet been identified. 1. The ideal replacement tritium pump would be hermetically sealed and contain no polymer components or oils. Polymers and oils degrade over time when they contact ionizing radiation. 2. Halogenated polymers (containing fluorine, chlorine, or both) and oils are commonly found in pumps. These materials have many properties that surpass those of hydrocarbon-based polymers and oils, including thermal stability (higher operating temperature) and better chemical resistance. Unfortunately, they are less resistant to degradation from ionizing radiation than hydrocarbon-based materials (in general). 3. Polymers and oils can form gaseous, condensable (HF, TF), liquid, and solid species when exposed to ionizing radiation. For example, halogenated polymers form HF and HCl, which are extremely corrosive upon reaction with water. If a pump containing polymers or oils must be used in a tritium system, the system must be designed to be able to process the unwanted by-products. Design features to mitigate degradation products include filters and chemical or physical traps (eg. cold traps, oil traps). 4. Polymer components can work in tritium systems, but must be replaced regularly. Polymer components performance should be monitored or be regularly tested, and regular replacement of components should be viewed as an expected normal event. A radioactive waste stream must be established to dispose of used polymer components and oil with an approved disposal plan developed based on the facility location and its regulators. Polymers have varying resistances to ionizing radiation - aromatic polymers such as polyimide Vespel (TM) and the elastomer EPDM (ethylene propylene diene monomer) have been found to be more resistant to degradation in tritium than other polymers. This report presents information to help select replacement pumps for Normetex pumps in tritium systems. Several pumps being considered as Normetex replacement pumps are discussed.
Navitas Advanced Solutions Group proposes a novel, commercially scalable approach to supply microporous silicon (μpSi) to lithium ion battery manufacturers. If successful, this project will result in a significant reduction in the cost and environmental impact of high capacity anodes that are needed to meet the EV Everywhere battery goals. Silicon nanocomposite materials have been identified as a viable anode technology for EV batteries. Presently, high capacity silicon-based anodes rely either on materials that are expensive (e. g., silane or nano-silicon powder) or on processes that are limited by low yield methods (e.g., chemical vapor deposition). Microporous silicon potentially avoids these limitations and is attracting increasing attention as a lower cost alternative for the manufacture of high capacity silicon-based anodes. Microporous silicon suitable for EV batteries is not currently available as a commodity material. Microporous silicon can be produced at lab scale through a metal catalyzed hydrofluoric acid etching process. However, this process is expensive and hazardous. Our proposed production route will facilitate the availability of μpSi to lithium ion battery producers and developers at a scale and cost able to support EV battery production. Under the Vehicle Technologies FOA AOI 4 seeks Advances in Existing and Next-Generation Battery Material Manufacturing to reduce the cost of EV batteries. The EV Everywhere initiative establishes a goal of $100/kWh system level cost for an EV battery. This cost target can be met with moderate risk through pairing silicon-based high capacity anodes with lithium metal-rich nickel manganese cobalt oxide 'LMR-NMC' cathodes. For this set of assumptions, the silicon anode active material cost would need to be <$25/kg. The Navitas µpSi powder manufacturing process will reach this target through a combination of low-cost commodity raw materials and reactants with scalable and low environmental impact processes. Processing will involve mechanical milling and thermal reduction operations that are in wide application at industrial scale. The goal of this program is to reach most or all of the MRL 6 criteria in a pilot scale demonstration for the manufacturing of porous silicon powder, while minimizing raw material added cost and limiting hazardous and environmental impact and using scalable industrial processing (i.e. mechanical milling, thermal reduction). The Navitas μpSi fabrication process represents a novel approach to reduce the cost of silicon anode material manufacturing. This process has been shown to be more efficient (higher yield) and economical on scaling up than conventional metal-assisted etching. The process significantly reduces the cost on $/mAh basis versus existing anode materials. The μpSi powders can be modified to form nanocomposite structures through blending with graphite or coating with carbon or a metal oxide to decrease initial capacity loss (ICL) and improve cell cycle life, a key barrier to adoption of silicon anodes into EV batteries. The impact of this technology will be driven by the projected rate of EV adoption and market share. By reducing battery cost, the proposed technology will stimulate EV adoption rate. Assuming this technology enables capturing an additional 6% of the present PHEV + EV market the reduction in petroleum consumption would be 90,000 gallons of gasoline per day, or 1.6M barrels per year. The carbon emissions from a gallon of gasoline = 2.4 kg/gallon. Thus, if the proposed technology was incorporated into just 0.1% of all new vehicles produced and if all the electricity to power those electric-drive vehicles was produced from clean, renewable sources such as wind and solar, it would result in 15K metric tons/yr reduction of CO2 emissions.
LLNS, as manager and operator of Lawrence Livermore National Laboratory (LLNL), and UTMB have a multi-year, ongoing, collaborative effort. This effort aimed to improve preparedness in Galveston County, Texas region and, more generally, identifying improved methods to (a) understand and mitigate the hazards of a large industrial chemical release and (b) implement and adapt national response plans and guidance to meet local planning and response needs. This CRADA was one portion of that effort and was intended to support the Hydrofluoric Acid (HF) Incident Symposium. This annual symposium engages a wide variety of government, private, and non-profit groups to (a) increase the resiliency, and reduce the vulnerability, of communities at risk of being impacted by major releases of toxic industrial chemicals and (b) guide the development of policies and best practices to prevent and manage these events. This CRADA project was originally scheduled for six (6) months and consisted of five major tasks.
MXenes are a relatively new class of nanomaterial consisting of alternating layers of transition metals and carbon or nitrogen, capped off on either end by terminal groups, usually from the P-block. They have been considered for a wide range of purposes, including hydrogen storage. In this study, thermogravimetric analysis and mass spectrometry residual gas analysis are performed on Ti 3 C 2 T x and Ti 2 CT x to characterize their terminal groups. The hydrogen absorption capabilities of the heat-treated samples are measured using a Sievert apparatus and compared against untreated samples. This reveals that, during heating, the MXenes lose hydrogen, water, fluoride, hydrofluoric acid, and carbon dioxide. Isothermal absorption measurements suggest that the removal of termination groups might improve hydrogen uptake kinetics at high temperatures, but has little effect at room temperatures.
Hydrogen fluoride readily associates with water vapor in the air to form the H 2 O-HF complex, which has optical absorption properties that are different from those of unassociated hydrogen fluoride. Consequently, to accurately quantify the total amount of hydrogen fluoride coming from an industrial stack or vent, for example, requires that the complexed amount of hydrogen fluoride be accounted for. To do this, the equilibrium constant for the association reaction is needed. Using statistical mechanical methods, Adebayo and coworkers [Adebayo SLA, AC Legon and DJ Millen. 1991. J. Chem. Soc. Faraday Trans. 87:443-447.] made an estimate of this equilibrium constant based on measured and estimated spectroscopic values for the complex. This value is K eq = 84(18) but has never been confirmed experimentally. In the research described herein, we have measured the equilibrium constant for the formation of H 2 O-HF by monitoring the decrease in the infrared absorption features of water vapor and hydrogen fluoride in mixtures of these two vapors in a temperature-regulated cell. Our experimental values for K eq at 25 °C, based on the diminution of the water vapor and HF transitions, are 77(46) and 51(24), respectively. The decay of the spectral features continues long after (hours) the two vapors are mixed in the gas cell. This suggests that other reactions (the growth of a film of hydrofluoric acid, perhaps) are taking place. While the experimental results agree reasonably well with the calculated equilibrium value of Adebayo et al., further improvements in experimental and analysis techniques are needed to reduce the uncertainties in the experimental results.
The collaboration between the Superconducting Quantum Materials and Systems Center (SQMS) and Rigetti Computing produced several advancements in our understanding of the role of materials characteristics in quantum processor performance. This partnership leverages SQMS's extensive characterization infrastructure and cutting-edge research in materials, and Rigetti's expertise in quantum hardware and robust nanofabrication to improve precision and performance of Rigetti's test QPUs. Qubit frequency is determined in large part by the properties of Josephson junctions (JJs) made of amorphous oxide tunnel barriers; the Alternating-Bias Assisted Annealing (ABAA) process allows us to tune JJs to their desired frequency [1]. Work by SQMS researchers in characterizing high-precision JJs post-processed (using ABAA) have yielded crucial information on the nature of the structure and chemical bonding uniformity of the ABAA processed amorphous oxides. Performance has also been improved through a comprehensive series of experiments that tested encapsulation and surface treatment. Encapsulation of the niobium metal layer with tantalum resulted in an T1 improvement of 80%, experimentally confirming the role of Nb surface losses in qubit performance [2]. Pre-treatment of the underlying silicon surface prior to JJ fabrication by replacing a buffered oxide etch (BOE) with hydrofluoric acid (HF) followed by aqueous ammonium fluoride (NH4F) has shown a statistically significant improvement of T1 by 22%, and reduction in the number of strongly-coupled TLS [3]. These examples, as well as many other published and ongoing investigations, demonstrate the mutual benefits that come from Rigetti's involvement in the SQMS collaboration. [1] - Pappas, D.P., et al. (2024). https://doi.org/10.1038/s43246-024-00596-z [2] - Bal, M., et al. (2024). https://doi.org/10.1038/s41534-024-00840-x [3] Kopas, C. J. et al. Preprint at https://doi.org/10.48550/arXiv.2408.02863 (2024).
UF6 is highly reactive and readily hydrolyzes in contact with moisture to form uranyl fluoride (UO2 F2 ) and hydrofluoric acid (HF), however there is disagreement between experimental and computation investigations into the intermediates of the reaction. • As the hydrolysis reaction occurs at very fast time scales, it is difficult to investigate the intermediates and reaction kinetics experimentally. • Previous experiments at SRNL have had some success at halting and studying the UF6 hydrolysis reaction using cryogenic techniques, however isotopic substitution studies limit possible identity of intermediate compounds. • Primary goal of this project is to capture and study reaction intermediates produced during the gas phase hydrolysis of UF6 via supersonic expansion.
Sulfur hexafluoride (SF₆) is recognized as the most potent greenhouse gas used in the power transmission and semiconductor sectors. In the past decade, its global emissions have increased sharply, largely due to the absence of effective disposal and recovery pathways. This concern was formally addressed under the Kyoto Protocol, which urged participating nations to adopt measures to limit SF₆ emissions and mitigate its role in climate change. In recent years, various abatement strategies have been explored, including non-thermal plasma (NTP) technologies such as radio frequency, microwave, dielectric barrier discharge, and electron beam systems. While these methods can decompose SF₆, they also produce hazardous by-products like sulfur oxyfluorides, sulfur dioxide, hydrofluoric acid, and fluorine gas. Because these compounds pose both environmental and health risks, replacing traditional disposal practices with modern, more effective treatment methods has become an urgent priority.
Hydrofluoric acid (HF)-free bipolar pulsed electropolishing (BPEP) offers an environmentally sustainable alternative to conventional Buffered Chemical Polishing (BCP) and Electropolishing (EP) techniques for superconducting radiofrequency (SRF) cavities. Recent studies at Jefferson Lab have demonstrated that a single-cell 1.3 GHz niobium cavity processed using HF-free BPEP achieved an accelerating gradient Eacc of 35 MV/m with a quality factor Q0 of 1E10 at 2 K, following extensive research and optimization. This talk will highlight the challenges encountered in developing this technique, key insights gained from experimental studies, and ongoing efforts to enhance its capabilities. In particular, we will explore its potential for refining Nb3Sn-coated niobium cavities via vapor diffusion techniques and for electroplating Nb3Sn films onto various cavity substrates, contributing to the advancement of high-performance SRF systems.
Silicon carbide (SiC) formed through pyrolysis of preceramic polymers loaded with SiC particles has gained significant attention for applications such as coatings, composite matrix modifications, and most importantly additive manufacturing. This work presents combined synchrotron XRD, Raman spectroscopy, scanning electron microscopy, nano-indentation, and Vickers indentation of pyrolysis bonded SiC to shed light on the changes of composition and mechanical properties of these materials. Characterization was performed on samples that were heat treated ranging from the synthesis 850 °C up to 1500 °C. Pre-treatments of the powders prior to pellet synthesis, such as heat treatment and etching using a hydrofluoric acid (HF), were investigated. It is shown that the degradation of mechanical properties when exposed to higher temperatures is due to the burnout of amorphous carbon clusters remnant of the pyrolysis process of the preceramic polymer. Furthermore, prior HF etching and removal of the native oxide layer of the powders showed improved density and hardness values in the final pellets. The average Vickers hardness of the control samples were 4.59 GPa and later 3.74 GPa when exposed to 1500 °C, while the samples synthesized using powders that were etched with HF had an average hardness value of 9.37 GPa and later 6.86 GPa when exposed to 1500 °C.
Chemical abrasion is a technique that combines thermal annealing and partial dissolution in hydrofluoric acid (HF) to selectively remove radiation-damaged portions of zircon crystals prior to U–Pb isotopic analysis, and it is applied ubiquitously to zircon prior to U–Pb isotope dilution thermal ionization mass spectrometry (ID-TIMS). The mechanics of zircon dissolution in HF and the impact of different leaching conditions on the zircon structure, however, are poorly resolved. We present a microstructural investigation that integrates microscale X-ray computed tomography (µCT), scanning electron microscopy, and Raman spectroscopy to evaluate zircon dissolution in HF. We show that µCT is an effective tool for imaging metamictization and complex dissolution networks in three dimensions. Acid frequently reaches crystal interiors via fractures spatially associated with radiation damage zoning and inclusions to dissolve soluble high-U zones, some inclusions, and material around fractures, leaving behind a more crystalline zircon residue. Other acid paths to crystal cores include the dissolution of surface-reaching inclusions and the percolation of acid across zones with high defect densities. In highly crystalline samples dissolution is crystallographically controlled with dissolution proceeding almost exclusively along the c axis. Increasing the leaching temperature from 180 to 210 °C results in deeper etching textures, wider acid paths, more complex internal dissolution networks, and greater volume losses. How a grain dissolves strongly depends on its initial radiation damage content and defect distribution as well as the size and position of inclusions. As such, the effectiveness of any chemical abrasion protocol for ID-TIMS U–Pb geochronology is likely sample-dependent. We also briefly discuss the implications of our findings for deep-time (U-Th)/He thermochronology.
Here, we present cosmogenic- 10 Be and cosmogenic- 3 He data from Ferrar dolerite pyroxenes in surficial rock samples and a bedrock core from the McMurdo Dry Valleys, Antarctica, with the goal of refining the laboratory methods for extracting beryllium from pyroxene, further estimating the 10 Be production rate in pyroxene and demonstrating the applicability of 10 Be– 3 He in mafic rock. The ability to routinely measure cosmogenic 10 Be in pyroxene will open new opportunities for quantifying exposure durations and Earth surface processes in mafic rocks. We describe scalable laboratory methods for isolating beryllium from pyroxene, which include a simple hydrofluoric acid leaching procedure for removing meteoric 10 Be and the addition of a pH 8 precipitation step to reduce the cation load prior to ion exchange chromatography. 10 Be measurements in pyroxene from the surface samples have apparent 3 He exposure ages of 1–6 Myr. We estimate a spallation production rate for 10 Be in pyroxene, referenced to 3 He, of 3.6 ± 0.2 atoms g –1 yr –1 . 10 Be and 3 He measurements in the bedrock core yield initial estimates for parameters associated with 10 Be and 3 He production by negative-muon capture ($f_{10}^{*}$ = 0.00183 and $f_{3}^{*}f_{C}f_{D}$ = 0.00337). Next, we demonstrate that the 10 Be– 3 He pair in pyroxene can be used to simultaneously resolve erosion rates and exposure ages, finding that the measured cosmogenic-nuclide concentrations in our surface samples are best explained by 2–8 Myr of exposure at erosion rates of 0–35 cm Myr –1 . Finally, given the low 10 Be in our laboratory blanks (average of 5.7 × 10 3 atoms), the reported measurement precision, and our estimated production rate, it should be possible to measure 2 g samples with 10 Be concentrations of 6 × 10 4 and 1.5 × 10 4 atoms g –1 with 5 % and 15 % uncertainty, respectively. With this level of precision, Last Glacial Maximum to Late Holocene surfaces can now be dated with 10 Be in pyroxene. Application of 10 Be in pyroxene, alone or in combination with 3 He, will expand possibilities for investigating glacial histories and landscape change in mafic rock.
Quantitative determination of nitrogen in titanium nitride involves dissolution of TiN in 10M hydrofluoric acid containing an oxidant. Released nitrogen is determined as ammonia. Best oxidizers are ferric chloride, potassium iodate, and potassium dichromate.
Apollo 11 lunar fines examined for organic compounds via solvent extraction, vacuum crushing, programmed heating and hydrofluoric acid etching
Liners for nitric and hydrofluoric acid tanks show no sign of deterioration after 18 months of continuous use. Each side of each edge of the polypropylene sheets is chamfered, and sheets are welded from both sides with polypropylene filler rod and a special hot-air welding torch.
Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process.
The Apollo 16 SWC experiment is a continuation of the earlier experiments; however, an essential change was introduced in the solar wind particle collection technique. Platinum surfaces were incorporated in the collector foil, and use was made of a layer technique for distinguishing particles of different energies and different directions of arrival. The improvements and the expanded scope of the Apollo 16 experiment, relative to the earlier SWC experiments, can be summarized as follows: elimination of possible residual dust contamination by treating the platinum foil sections with dilute hydrofluoric acid before analysis; increased accuracy of solar wind argon abundance; determination of solar wind albedo; and search for helium in the energy range above approximately 40 KeV/nucleon.