SEARCH · Engineering Papers
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.
XeF2 is Cyanogen Chloride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is zero-dimensional and consists of two XeF2 clusters. Xe is bonded in a linear geometry to two equivalent F atoms. Both Xe–F bond lengths are 2.08 Å. F is bonded in a single-bond geometry to one Xe atom.
XeF4 is Protactinium structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two XeF4 clusters. Xe is bonded in a square co-planar geometry to four equivalent F atoms. All Xe–F bond lengths are 2.04 Å. F is bonded in a single-bond geometry to one Xe atom.
XeF2IF5 is Heusler-derived structured and crystallizes in the tetragonal I4/m space group. The structure is zero-dimensional and consists of four IF5 clusters and four XeF2 clusters. In each IF5 cluster, I is bonded in a square pyramidal geometry to five F atoms. There is one shorter (1.87 Å) and four longer (1.93 Å) I–F bond length. There are two inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one I atom. In the second F site, F is bonded in a single-bond geometry to one I atom. In each XeF2 cluster, Xe is bonded in a linear geometry to two equivalent F atoms. Both Xe–F bond lengths are 2.09 Å. F is bonded in a single-bond geometry to one Xe atom.
XeHgSb3F17 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one XeHgSb3F17 sheet oriented in the (0, 0, 1) direction. Xe is bonded in a single-bond geometry to one Hg atom. The Xe–Hg bond length is 2.86 Å. Hg is bonded in a 5-coordinate geometry to one Xe and six F atoms. There are a spread of Hg–F bond distances ranging from 2.36–2.65 Å. There are three inequivalent Sb sites. In the first Sb site, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 33°. There are a spread of Sb–F bond distances ranging from 1.88–2.07 Å. In the second Sb site, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 33°. There are a spread of Sb–F bond distances ranging from 1.88–2.09 Å. In the third Sb site, Sb is bonded in an octahedral geometry to six F atoms. There are a spread of Sb–F bond distances ranging from 1.88–1.97 Å. There are seventeen inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Hg and one Sb atom. In the second F site, F is bonded in a distorted single-bond geometry to one Hg and one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a bent 120 degrees geometry to one Hg and one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a single-bond geometry to one Sb atom. In the seventh F site, F is bonded in a single-bond geometry to one Sb atom. In the eighth F site, F is bonded in a single-bond geometry to one Sb atom. In the ninth F site, F is bonded in a single-bond geometry to one Sb atom. In the tenth F site, F is bonded in a bent 150 degrees geometry to two Sb atoms. In the eleventh F site, F is bonded in a single-bond geometry to one Sb atom. In the twelfth F site, F is bonded in a single-bond geometry to one Sb atom. In the thirteenth F site, F is bonded in a single-bond geometry to one Sb atom. In the fourteenth F site, F is bonded in a distorted single-bond geometry to one Hg and one Sb atom. In the fifteenth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixteenth F site, F is bonded in a distorted single-bond geometry to one Hg and one Sb atom. In the seventeenth F site, F is bonded in a bent 150 degrees geometry to one Hg and one Sb atom.
AuSb2(XeF6)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one AuSb2(XeF6)2 cluster. Xe is bonded in a single-bond geometry to one Au atom. The Xe–Au bond length is 2.77 Å. Au is bonded in a linear geometry to two equivalent Xe and two equivalent F atoms. Both Au–F bond lengths are 2.18 Å. Sb is bonded in an octahedral geometry to six F atoms. There are a spread of Sb–F bond distances ranging from 1.90–2.04 Å. There are six inequivalent F sites. In the first F site, F is bonded in a distorted bent 150 degrees geometry to one Au and one Sb atom. In the second F site, F is bonded in a single-bond geometry to one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a single-bond geometry to one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a single-bond geometry to one Sb atom.
XeNa4O14 crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. Xe is bonded in a single-bond geometry to one O atom. The Xe–O bond length is 2.03 Å. There are two inequivalent Na sites. In the first Na site, Na is bonded in a 3-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.40–3.02 Å. In the second Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.21–2.57 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.35 Å) and one longer (1.41 Å) O–O bond length. In the second O site, O is bonded in a distorted T-shaped geometry to two Na and one O atom. The O–O bond length is 1.27 Å. In the third O site, O is bonded in a distorted trigonal planar geometry to two Na and one O atom. In the fourth O site, O is bonded in a 4-coordinate geometry to three Na and one O atom. The O–O bond length is 1.37 Å. In the fifth O site, O is bonded in a 2-coordinate geometry to two equivalent Na and two equivalent O atoms. In the sixth O site, O is bonded in a 4-coordinate geometry to three Na and one O atom. In the seventh O site, O is bonded in a distorted T-shaped geometry to one Xe and two equivalent Na atoms. In the eighth O site, O is bonded in a distorted water-like geometry to one Na and one O atom.
XeC3F2B(CF3)4(CF)3 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of twelve fluoromethane molecules, four B(CF3)4 clusters, and four XeC3F2 clusters. In each B(CF3)4 cluster, B is bonded in a tetrahedral geometry to four C atoms. All B–C bond lengths are 1.65 Å. There are four inequivalent C sites. In the first C site, C is bonded to one B and three F atoms to form corner-sharing CBF3 tetrahedra. All C–F bond lengths are 1.38 Å. In the second C site, C is bonded to one B and three F atoms to form corner-sharing CBF3 tetrahedra. There is two shorter (1.38 Å) and one longer (1.39 Å) C–F bond length. In the third C site, C is bonded to one B and three F atoms to form corner-sharing CBF3 tetrahedra. There is two shorter (1.37 Å) and one longer (1.41 Å) C–F bond length. In the fourth C site, C is bonded to one B and three F atoms to form corner-sharing CBF3 tetrahedra. There are a spread of C–F bond distances ranging from 1.37–1.39 Å. There are eleven inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one C atom. In the second F site, F is bonded in a single-bond geometry to one C atom. In the third F site, F is bonded in a single-bond geometry to one C atom. In the fourth F site, F is bonded in a single-bond geometry to one C atom. In the fifth F site, F is bonded in a single-bond geometry to one C atom. In the sixth F site, F is bonded in a single-bond geometry to one C atom. In the seventh F site, F is bonded in a single-bond geometry to one C atom. In the eighth F site, F is bonded in a single-bond geometry to one C atom. In the ninth F site, F is bonded in a single-bond geometry to one C atom. In the tenth F site, F is bonded in a single-bond geometry to one C atom. In the eleventh F site, F is bonded in a single-bond geometry to one C atom. In each XeC3F2 cluster, Xe is bonded in a single-bond geometry to one C atom. The Xe–C bond length is 2.13 Å. There are three inequivalent C sites. In the first C site, C is bonded in a single-bond geometry to one C and one F atom. The C–C bond length is 1.39 Å. The C–F bond length is 1.34 Å. In the second C site, C is bonded in a trigonal planar geometry to one Xe and two C atoms. The C–C bond length is 1.39 Å. In the third C site, C is bonded in a distorted single-bond geometry to one C and one F atom. The C–F bond length is 1.34 Å. There are two inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one C atom. In the second F site, F is bonded in a single-bond geometry to one C atom.
XeNa4O12 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Xe is bonded in a linear geometry to two equivalent O atoms. Both Xe–O bond lengths are 2.17 Å. There are two inequivalent Na sites. In the first Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.24–2.64 Å. In the second Na site, Na is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of Na–O bond distances ranging from 2.33–3.00 Å. There are six inequivalent O sites. In the first O site, O is bonded to one Xe and three Na atoms to form corner-sharing ONa3Xe tetrahedra. In the second O site, O is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na and one O atom. The O–O bond length is 1.26 Å. In the third O site, O is bonded in a distorted see-saw-like geometry to three Na and one O atom. The O–O bond length is 1.37 Å. In the fourth O site, O is bonded in a distorted trigonal planar geometry to two equivalent Na and one O atom. The O–O bond length is 1.36 Å. In the fifth O site, O is bonded in a 3-coordinate geometry to one Na and two O atoms. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Na and one O atom.
XeNa4O12 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Xe is bonded in a linear geometry to two equivalent O atoms. Both Xe–O bond lengths are 2.16 Å. There are two inequivalent Na sites. In the first Na site, Na is bonded in a 7-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.32–3.00 Å. In the second Na site, Na is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Na–O bond distances ranging from 2.36–3.03 Å. There are six inequivalent O sites. In the first O site, O is bonded to one Xe and three Na atoms to form corner-sharing ONa3Xe tetrahedra. In the second O site, O is bonded in a trigonal non-coplanar geometry to two equivalent Na and one O atom. The O–O bond length is 1.28 Å. In the third O site, O is bonded in a bent 120 degrees geometry to two equivalent Na atoms. In the fourth O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one O atom. The O–O bond length is 1.27 Å. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent Na and one O atom. In the sixth O site, O is bonded in a trigonal non-coplanar geometry to two equivalent Na and one O atom.
Xe2Au2Sb3F19 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of one Xe2Au2Sb3F19 ribbon oriented in the (0, 1, 1) direction. Xe is bonded in a single-bond geometry to one Au atom. The Xe–Au bond length is 2.69 Å. Au is bonded in a distorted T-shaped geometry to one Xe and three F atoms. There are a spread of Au–F bond distances ranging from 2.09–2.25 Å. There are two inequivalent Sb sites. In the first Sb site, Sb is bonded in an octahedral geometry to six F atoms. There are a spread of Sb–F bond distances ranging from 1.90–2.02 Å. In the second Sb site, Sb is bonded in an octahedral geometry to six F atoms. There are a spread of Sb–F bond distances ranging from 1.90–1.99 Å. There are nine inequivalent F sites. In the first F site, F is bonded in a linear geometry to two equivalent Au atoms. In the second F site, F is bonded in a bent 150 degrees geometry to one Au and one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a single-bond geometry to one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a single-bond geometry to one Sb atom. In the seventh F site, F is bonded in a single-bond geometry to one Sb atom. In the eighth F site, F is bonded in a distorted bent 150 degrees geometry to one Au and one Sb atom. In the ninth F site, F is bonded in a single-bond geometry to one Sb atom.
XeNa4O12 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Xe is bonded in a linear geometry to two equivalent Na atoms. Both Xe–Na bond lengths are 3.30 Å. There are two inequivalent Na sites. In the first Na site, Na is bonded in a 6-coordinate geometry to one Xe and six O atoms. There are a spread of Na–O bond distances ranging from 2.32–2.83 Å. In the second Na site, Na is bonded to seven O atoms to form a mixture of distorted corner and edge-sharing NaO7 hexagonal pyramids. There are a spread of Na–O bond distances ranging from 2.41–2.79 Å. There are six inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Na and one O atom. The O–O bond length is 1.27 Å. In the second O site, O is bonded in a distorted rectangular see-saw-like geometry to three Na and one O atom. The O–O bond length is 1.35 Å. In the third O site, O is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na and one O atom. In the fourth O site, O is bonded in a distorted T-shaped geometry to two equivalent Na and one O atom. The O–O bond length is 1.30 Å. In the fifth O site, O is bonded in a trigonal planar geometry to two equivalent Na and one O atom. In the sixth O site, O is bonded in a 4-coordinate geometry to three Na and one O atom.
XeAuAsF3Sb2F11 crystallizes in the orthorhombic Pna2_1 space group. The structure is zero-dimensional and consists of four Sb2F11 clusters and four XeAuAsF3 clusters. In each Sb2F11 cluster, there are two inequivalent Sb sites. In the first Sb site, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Sb–F bond distances ranging from 1.89–2.08 Å. In the second Sb site, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Sb–F bond distances ranging from 1.90–2.09 Å. There are eleven inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to two Sb atoms. In the second F site, F is bonded in a single-bond geometry to one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a single-bond geometry to one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a single-bond geometry to one Sb atom. In the seventh F site, F is bonded in a single-bond geometry to one Sb atom. In the eighth F site, F is bonded in a single-bond geometry to one Sb atom. In the ninth F site, F is bonded in a single-bond geometry to one Sb atom. In the tenth F site, F is bonded in a single-bond geometry to one Sb atom. In the eleventh F site, F is bonded in a single-bond geometry to one Sb atom. In each XeAuAsF3 cluster, Xe is bonded in a single-bond geometry to one Au atom. The Xe–Au bond length is 2.67 Å. Au is bonded in a linear geometry to one Xe and one As atom. The Au–As bond length is 2.35 Å. As is bonded in a 4-coordinate geometry to one Au and three F atoms. All As–F bond lengths are 1.72 Å. There are three inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one As atom. In the second F site, F is bonded in a single-bond geometry to one As atom. In the third F site, F is bonded in a single-bond geometry to one As atom.
XeF2Sb2F11 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two Sb2F11 clusters and two XeF2 clusters. In each Sb2F11 cluster, there are two inequivalent Sb sites. In the first Sb site, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are a spread of Sb–F bond distances ranging from 1.90–2.08 Å. In the second Sb site, Sb is bonded to six F atoms to form corner-sharing SbF6 octahedra. The corner-sharing octahedral tilt angles are 12°. There are a spread of Sb–F bond distances ranging from 1.90–2.06 Å. There are eleven inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Sb atom. In the second F site, F is bonded in a single-bond geometry to one Sb atom. In the third F site, F is bonded in a single-bond geometry to one Sb atom. In the fourth F site, F is bonded in a single-bond geometry to one Sb atom. In the fifth F site, F is bonded in a single-bond geometry to one Sb atom. In the sixth F site, F is bonded in a linear geometry to two Sb atoms. In the seventh F site, F is bonded in a single-bond geometry to one Sb atom. In the eighth F site, F is bonded in a single-bond geometry to one Sb atom. In the ninth F site, F is bonded in a single-bond geometry to one Sb atom. In the tenth F site, F is bonded in a single-bond geometry to one Sb atom. In the eleventh F site, F is bonded in a single-bond geometry to one Sb atom. In each XeF2 cluster, Xe is bonded in a linear geometry to two equivalent F atoms. Both Xe–F bond lengths are 2.03 Å. F is bonded in a single-bond geometry to one Xe atom.
(XeF2)4(AsF6)2O2 crystallizes in the tetragonal I4/mcm space group. The structure is zero-dimensional and consists of four water molecules, four AsF6 clusters, and eight XeF2 clusters. In each AsF6 cluster, As is bonded in an octahedral geometry to six equivalent F atoms. All As–F bond lengths are 1.78 Å. F is bonded in a single-bond geometry to one As atom. In each XeF2 cluster, Xe is bonded in a linear geometry to two equivalent F atoms. Both Xe–F bond lengths are 2.09 Å. F is bonded in a single-bond geometry to one Xe atom.
The NEXT experiment aims at the sensitive search of the neutrinoless double beta decay in 136 Xe, using high-pressure gas electroluminescent time projection chambers. The NEXT-White detector is the first radiopure demonstrator of this technology, operated in the Laboratorio Subterráneo de Canfranc. Achieving an energy resolution of 1% FWHM at 2.6 MeV and further background rejection by means of the topology of the reconstructed tracks, NEXT-White has been exploited beyond its original goals in order to perform a neu- trinoless double beta decay search. The analysis considers the combination of 271.6 days of 136 Xe-enriched data and 208.9 days of 136Xe-depleted data. A detailed background modeling and measurement has been developed, ensuring the time stability of the radiogenic and cosmogenic contributions across both data samples. Limits to the neutrinoless mode are obtained in two alternative analyses: a background-model-dependent approach and a novel direct background-subtraction technique, offering results with small dependence on the background model assumptions. With a fiducial mass of only 3.50 ± 0.01 kg of 136 Xe-enriched xenon, 90% C.L. lower limits to the neutrinoless double beta decay are found in the $T^{0v}_{1/2} > 5.5 \times 10^{23} - 1.3 \times 10^{24}$ yr range, depending on the method. The presented techniques stand as a proof-of-concept for the searches to be implemented with larger NEXT detectors.
A continuous flow-through, real-time radioxenon sensor array has been designed to monitor either 127 Xe or 133 Xe tracer gas as part of a series of underground chemical explosions in the Low-Yield Nuclear Monitoring (LYNM) Physics Experiment 1 (PE1). The sensors are pairs of shielded thallium-doped sodium iodide gamma-ray detectors that surround a gas measurement chamber. Each measurement chamber is connected to a sampling location in the geology surrounding the chemical explosion or in the access tunnel. The first experiment in the series, PE1 A, occurred in 2023 and the system quantified the 127 Xe tracer gas in the gas sampling lines for four weeks following the experiment execution. The array generated a set of radioxenon concentration time series with a 15-minute resolution that will be used to refine subsurface gas transport models.
Adsorption of noble gas fission products onto naturally occurring minerals is of interest for its potential to retain or retard emissions from nuclear fuel reprocessing operations or underground nuclear explosions. However, experimental studies of trace noble gas adsorption in the presence of air and water have largely focused on synthetic materials, such as activated carbon or metal-organic frameworks. Here, in this study, adsorption of Kr and Xe onto the naturally occurring zeolitic mineral clinoptilolite is studied in the presence of nitrogen and water. By varying the composition of the gas phase and monitoring the change in the combined adsorbate mass, the adsorbed concentration of noble gas is calculated gravimetrically. For dry clinoptilolite, the concentration of adsorbed Kr and Xe is linearly correlated with noble gas pressure and Henry's Law appears satisfactory, despite the presence of nitrogen at atmospheric pressures. However, the presence of water significantly reduces the adsorbed concentration of both Kr and Xe, which is typical in nanoporous sorbents. Here, an empirical bivariate model is presented, combining the Henry's Law adsorption model for a dry adsorbent with the exponential reduction in the presence of water, as reported by Lungu and Underhill in 1999. This model provides a means to estimate the adsorbate concentration at the trace partial pressures and higher water contents relevant to field-scale modeling of fission gas transport through the vadose zone.
For many atmospheric monitoring applications, networks of measurement sites—such as the radionuclide stations of the International Monitoring System—can be sparse. With measurement locations potentially hundreds to thousands of kilometers from a release it is important to quantify the effects of physical processes on transport and dispersion of plumes between source and measurement locations. This study addresses the effects of background sources and topography resolution near the release location of radionuclides. We use the Weather Research and Forecasting (WRF) model with inline chemistry to investigate (1) how an additional, time-varying source of 133 Xe, such as an operational medical isotope production facility, contributes to activity concentration measurements at monitoring sites, and (2) how complex topography influences on atmospheric conditions near emission sources impact plume concentrations at varying distances from the source. Two 133 Xe emission sources, including (1) a high flux rate of short duration representing an explosive event, and (2) a variable and continuous background source, are simulated. The continuous background source contributes significantly to total 133 Xe concentrations at several monitoring stations. Further, a WRF simulation at 9 km horizontal resolution is compared with a nested grid simulation, where the innermost domain has a resolution of 1 km. Increased topographic resolution leads to an improved representation of plume responses to local winds, with topographic influences greatest at locations closest to the sources. Differences between the two domain resolutions decrease at greater distances from the sources, as plumes have time to spread and mix and are influenced by synoptic scale circulation patterns that are represented similarly in both simulations.