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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Measurement of the absolute branching fraction of Λ c + → p K S 0 η decays

Based on 586 pb -1 of e + e - annihilation data collected at a center-of-mass energy of √s = 4.6 GeV with the BESIII detector at the BEPCII collider, the absolute branching fraction of $Λ^+_c$ → $pK^0_Sη$ decays is measured for the first time to be $B$($Λ^+_c$ → $pK^0_Sη$) = (0.414±0.084±0.028)%, where the first uncertainty is statistical and the second is systematic. The result is compatible with a previous CLEO result on the relative branching fraction B ( Λ c + → p K S 0 η ) B ( Λ c + → p K − π + ) , and consistent with theoretical predictions of SU(3) flavor symmetry.

$Λ^+_c$, Charmed baryon decays↗
DOE OSTI2024

Single-photon detection using large-scale high-temperature MgB2 sensors at 20 K

Abstract Ultra-fast single-photon detectors with high current density and operating temperature can benefit space and ground applications, including quantum optical communication systems, lightweight cryogenics for space crafts, and medical use. Here we demonstrate magnesium diboride (MgB 2 ) thin-film superconducting microwires capable of single-photon detection at 1.55 μ m optical wavelength. We used helium ions to alter the properties of MgB 2 , resulting in microwire-based detectors exhibiting single-photon sensitivity across a broad temperature range of up to 20 K, and detection efficiency saturation for 1 μ m wide microwires at 3.7 K. Linearity of detection rate vs incident power was preserved up to at least 100 Mcps. Despite the large active area of up to 400 × 400 μ m 2 , the reset time was found to be as low as ~ 1 ns. Our research provides possibilities for breaking the operating temperature limit and maximum single-pixel count rate, expanding the detector area, and raises inquiries about the fundamental mechanisms of single-photon detection in high-critical-temperature superconductors.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

Evolution of shell gaps in the neutron-poor calcium region from invariant-mass spectroscopy of 37,38 Sc, 35 Ca, 34 K

A fast secondary beam of 37 Ca impinged on a 9 Be target resulting in a set of reactions populating proton-rich nuclei including 35 Ca and the first observations of 37,38 Sc and 34 K. Invariant-mass spectroscopy, used to reconstruct proton decays for these nuclei, yielded three new ground-state masses and information on their low-lying structures. The newly measured mass excesses are: ΔM( 37 Sc) = 3500(410) keV, ΔM( 38 Sc) = –4656(14) keV, and ΔM( 34 K) = –1487(17) keV. These nuclei straddle the well-known Z = 20 shell closure as well as the N = 16 subshell closure. Furthermore, trends in separation energies help elucidate how nuclear structure evolves showing a fading of the Z = 20 shell gap for N ≥ 18 and indications of a N = 16 subshell gap.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Amplitude analysis of the B + → D + D - K + decay

Results are reported from an amplitude analysis of the B + → D + D - K + decay. The analysis is carried out using LHCb proton-proton collision data taken at $\sqrt{s}$ = 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb -1 . In order to obtain a good description of the data, it is found to be necessary to include new spin-0 and spin-1 resonances in the D - K + channel with masses around 2.9 GeV/c 2 , and a new spin-0 charmonium resonance in proximity to the spin-2 χ c2 (3930) state.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Amplitude analysis of the Λ c + → p K - π + decay and Λ c + baryon polarization measurement in semileptonic beauty hadron decays

An amplitude analysis of Λ c + → p K - π + decays together with a measurement of the Λ c + polarization vector in semiōleptonic beauty hadron decays is presented. A sample of 400 000 candidates is selected from proton-proton collisions recorded by the LHCb detector at a center-of-mass energy of 13 TeV. An amplitude model is developed and the resonance fractions as well as two- and three-body decay parameters are reported. The mass and width of the $Λ$(2000) state are also determined. A significant Λ c + polarization is found. A large sensitivity of the Λ c + → p K - π + decay to the polarization is seen, making the amplitude model suitable for Λ c + polarization measurements in other systems.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Model-Independent Study of Structure in B + → D + D - K + Decays

The only anticipated resonant contributions to B + → D + D - K + decays are charmonium states in the D + D - channel. A model-independent analysis, using LHCb proton-proton collision data taken at center of-mass energies of $\sqrt{s}$ = 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb -1 , is carried out to test this hypothesis. The description of the data assuming that resonances only manifest in decays to the D + D - pair is shown to be incomplete. This constitutes evidence for a new contribution to the decay, potentially one or more new charm-strange resonances in the D + K - channel with masses around 2.9 GeV/c 2

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Materials Data on K(CoS)2 by Materials Project

K(CoS)2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent S2- atoms. All K–S bond lengths are 3.31 Å. Co+1.50+ is bonded to four equivalent S2- atoms to form a mixture of edge and corner-sharing CoS4 tetrahedra. All Co–S bond lengths are 2.22 Å. S2- is bonded in a 4-coordinate geometry to four equivalent K1+ and four equivalent Co+1.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(USe3)2 by Materials Project

K(USe3)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a distorted body-centered cubic geometry to eight Se2- atoms. There are four shorter (3.42 Å) and four longer (3.44 Å) K–Se bond lengths. U+5.50+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of U–Se bond distances ranging from 2.88–2.95 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to four equivalent U+5.50+ atoms to form a mixture of distorted edge and corner-sharing SeU4 trigonal pyramids. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent K1+ and two equivalent U+5.50+ atoms. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent K1+ and two equivalent U+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(InAu2)2 by Materials Project

K(Au2In)2 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight equivalent Au1- atoms. All K–Au bond lengths are 3.44 Å. Au1- is bonded in a 10-coordinate geometry to two equivalent K1+, four equivalent Au1-, and four equivalent In+1.50+ atoms. There are a spread of Au–Au bond distances ranging from 2.84–3.02 Å. There are a spread of Au–In bond distances ranging from 2.88–2.98 Å. In+1.50+ is bonded in a 8-coordinate geometry to eight equivalent Au1- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(SnSe2)2 by Materials Project

K(SnSe2)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.36–3.97 Å. There are three inequivalent Sn+3.50+ sites. In the first Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form corner-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.53–2.60 Å. In the second Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form corner-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.51–2.61 Å. In the third Sn+3.50+ site, Sn+3.50+ is bonded in a rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Sn–Se bond distances ranging from 2.70–3.17 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted water-like geometry to two equivalent K1+ and two equivalent Sn+3.50+ atoms. In the second Se2- site, Se2- is bonded to two equivalent K1+ and two Sn+3.50+ atoms to form a mixture of distorted edge and corner-sharing SeK2Sn2 trigonal pyramids. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to one K1+ and two Sn+3.50+ atoms. In the fourth Se2- site, Se2- is bonded in a distorted L-shaped geometry to two equivalent K1+ and two Sn+3.50+ atoms. In the fifth Se2- site, Se2- is bonded to three equivalent K1+ and two Sn+3.50+ atoms to form distorted SeK3Sn2 trigonal bipyramids that share corners with three equivalent SeK3Sn2 trigonal bipyramids, corners with two equivalent SeK2Sn2 trigonal pyramids, edges with two equivalent SeK3Sn2 trigonal bipyramids, and an edgeedge with one SeK2Sn2 trigonal pyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(IrO2)4 by Materials Project

K(IrO2)4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.64 Å) and two longer (2.65 Å) K–O bond lengths. There are two inequivalent Ir+3.75+ sites. In the first Ir+3.75+ site, Ir+3.75+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing IrO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ir–O bond distances ranging from 1.97–2.08 Å. In the second Ir+3.75+ site, Ir+3.75+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing IrO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ir–O bond distances ranging from 1.99–2.07 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one K1+ and three equivalent Ir+3.75+ atoms to form a mixture of distorted edge and corner-sharing OKIr3 tetrahedra. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Ir+3.75+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three Ir+3.75+ atoms. In the fourth O2- site, O2- is bonded to one K1+ and three equivalent Ir+3.75+ atoms to form a mixture of distorted edge and corner-sharing OKIr3 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(WO3)6 by Materials Project

K(WO3)6 crystallizes in the trigonal P-31m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent O2- atoms to form KO12 cuboctahedra that share edges with twelve equivalent WO6 octahedra. All K–O bond lengths are 3.36 Å. W+5.83+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six equivalent WO6 octahedra and edges with two equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–30°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent W+5.83+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.83+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two equivalent W+5.83+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(Mo6S7)2 by Materials Project

K(Mo6S7)2 crystallizes in the trigonal P-31c space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight S2- atoms. There are two shorter (3.00 Å) and six longer (3.38 Å) K–S bond lengths. There are two inequivalent Mo+2.25+ sites. In the first Mo+2.25+ site, Mo+2.25+ is bonded in a see-saw-like geometry to four S2- atoms. There are a spread of Mo–S bond distances ranging from 2.44–2.57 Å. In the second Mo+2.25+ site, Mo+2.25+ is bonded to five S2- atoms to form a mixture of edge and corner-sharing MoS5 square pyramids. There are a spread of Mo–S bond distances ranging from 2.40–2.64 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to one K1+ and three equivalent Mo+2.25+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to one K1+ and four Mo+2.25+ atoms. In the third S2- site, S2- is bonded in a 4-coordinate geometry to four Mo+2.25+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(CuSe)2 by Materials Project

K(CuSe)2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent Se2- atoms. All K–Se bond lengths are 3.43 Å. Cu+1.50+ is bonded to four equivalent Se2- atoms to form a mixture of edge and corner-sharing CuSe4 tetrahedra. All Cu–Se bond lengths are 2.47 Å. Se2- is bonded in a 8-coordinate geometry to four equivalent K1+ and four equivalent Cu+1.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(WCl3)3 by Materials Project

K(WCl3)3 crystallizes in the trigonal P-31m space group. The structure is three-dimensional. K1+ is bonded to six equivalent Cl1- atoms to form distorted KCl6 octahedra that share corners with six equivalent WCl5 square pyramids and edges with three equivalent KCl6 octahedra. All K–Cl bond lengths are 3.39 Å. W+2.67+ is bonded to five Cl1- atoms to form WCl5 square pyramids that share corners with two equivalent KCl6 octahedra and corners with four equivalent WCl5 square pyramids. The corner-sharing octahedral tilt angles are 57°. There are a spread of W–Cl bond distances ranging from 2.41–2.51 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted trigonal planar geometry to two equivalent K1+ and one W+2.67+ atom. In the second Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two equivalent W+2.67+ atoms. In the third Cl1- site, Cl1- is bonded in a 2-coordinate geometry to two equivalent W+2.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(CoAs)2 by Materials Project

K(CoAs)2 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All K–As bond lengths are 3.41 Å. Co+2.50+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing CoAs4 tetrahedra. All Co–As bond lengths are 2.31 Å. As3- is bonded in a 8-coordinate geometry to four equivalent K1+ and four equivalent Co+2.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(Zr3I7)2 by Materials Project

K(Zr3I7)2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. K1+ is bonded in an octahedral geometry to six Zr+2.17+ atoms. There are two shorter (2.82 Å) and four longer (2.88 Å) K–Zr bond lengths. There are two inequivalent Zr+2.17+ sites. In the first Zr+2.17+ site, Zr+2.17+ is bonded to one K1+ and five I1- atoms to form a mixture of corner and edge-sharing ZrKI5 octahedra. The corner-sharing octahedra tilt angles range from 0–48°. There are a spread of Zr–I bond distances ranging from 2.91–3.05 Å. In the second Zr+2.17+ site, Zr+2.17+ is bonded to one K1+ and five I1- atoms to form a mixture of corner and edge-sharing ZrKI5 octahedra. The corner-sharing octahedra tilt angles range from 0–48°. There are a spread of Zr–I bond distances ranging from 2.93–3.13 Å. There are five inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted bent 120 degrees geometry to two equivalent Zr+2.17+ atoms. In the second I1- site, I1- is bonded in a distorted T-shaped geometry to three Zr+2.17+ atoms. In the third I1- site, I1- is bonded in an L-shaped geometry to two Zr+2.17+ atoms. In the fourth I1- site, I1- is bonded in an L-shaped geometry to two equivalent Zr+2.17+ atoms. In the fifth I1- site, I1- is bonded in an L-shaped geometry to two Zr+2.17+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(OsO3)2 by Materials Project

KOs2O6 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.99 Å) and three longer (3.35 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to six O2- atoms to form KO6 octahedra that share corners with twelve OsO6 octahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are three shorter (3.14 Å) and three longer (3.17 Å) K–O bond lengths. There are two inequivalent Os+5.50+ sites. In the first Os+5.50+ site, Os+5.50+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with three equivalent KO6 octahedra and corners with six OsO6 octahedra. The corner-sharing octahedra tilt angles range from 40–70°. There are a spread of Os–O bond distances ranging from 1.92–1.94 Å. In the second Os+5.50+ site, Os+5.50+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with three equivalent KO6 octahedra and corners with six equivalent OsO6 octahedra. The corner-sharing octahedra tilt angles range from 40–69°. All Os–O bond lengths are 1.92 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Os+5.50+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Os+5.50+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Os+5.50+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Os+5.50+ atoms.

36 MATERIALS SCIENCE↗