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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Tunable 2.1-micron Ho lidar for simultaneous range-resolved measurements of atmospheric water vapor and aerosol backscatter profiles

An eye-safe tunable differential-absorption lidar system has been developed for the range-resolved measurement of aerosol backscatter and water vapor in the atmosphere. The lidar uses a flash-lamp-pumped, Q-switched, 10-mJ solid-state Ho:YSGG laser that is continuously tunable over a 20/cm wavelength range near 2.084 microns. Both path-averaged and range-resolved measurements were performed with the Ho differential-absorption lidar system. Preliminary measurements have been made of the temporal variation of atmospheric aerosol backscatter and water-vapor profiles at ranges out to 1 km. These results indicate that the Ho lidar has the potential for the eye-safe remote sensing of atmospheric water vapor and backscatter profiles at longer ranges if suitably enhanced in laser power and laser linewidth.

Cha, Sungdo↗
NASA NTRS1993

Spectroscopic and lasing properties of Ho:Tm:LuAG

Ho:Tm:LuAG has been grown, examined spectroscopically, and lased at 2.1 microns. Ho:Tm:LuAG was selected for this experimental investigation when quantum-mechanical modeling predicted that it would be a good laser material for Ho laser operation on one of the 5I7 to 5I8 transitions. Lasing was achieved at 2.100 microns, one of the three wavelengths predicted to be most probable for laser action.

Barnes, Norman P.↗
NASA NTRS1994

Tropospheric HO determination by FAGE

In the measurement of tropospheric HO we have employed three low-pressure laser-excited fluorescence (LEF) experimental systems. These instruments operate by expanding the ambient air flow via a nozzle, followed by transit down a flowtube through a detection region traversed by the excitation laser beam. This sampling method we named FAGE (fluorescence assay with gas expansion). The instruments employed a hydrocarbon reagent, added below the nozzle, to remove HO for background measurement. In the second and third instruments, air sampling via parallel nozzles and tubes, with reagent addition alternating between two channels, permitted continuous signal measurement with simultaneous measurement of background. The first two instruments (FAGE1 and FAGE2) used 282 nm HO excitation by frequency-doubled tunable dye lasers, pumped by pulsed Nd:YAG lasers at 10-30 Hz repetition rate. The third instrument (FAGE3) uses 308 nm excitation in which the dye laser is pumped by a copper vapor laser, pulsed at 5600 Hz.

Hard, Thomas M.↗
NASA NTRS2008

Review of Tm and Ho Materials; Spectroscopy and Lasers

A review of Tm and Ho materials is presented, covering some fundamental aspects on the spectroscopy and laser dynamics in both single and co-doped systems. Following an introduction to 2- m lasers, applications and historical development, the physics of quasi-four level lasers, energy transfer and modeling are discussed in some detail. Recent developments in using Tm lasers to pump Ho lasers are discussed, and seen to offer some advantages over conventional Tm:Ho lasers. This article is not intended as a complete review, but as a primer for introducing concepts and a resource for further study.

Walsh, Brian M.↗
NASA NTRS2009

1.88 Micrometers InGaAsP Pumped, Room Temperature Ho: LuAG Laser

A room temperature, directly diode pumped Ho:LuAG laser oscillated for the first time. Direct pumping of the Ho upper laser manifold maximizes efficiency, minimizes heating, and eliminates Ho:Tm energy sharing. Design and performance are presented.

Barnes, Norman P.↗
NASA NTRS2012

Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric Re-187 and Ho-163 Spectra

The measurement of calorimetric spectra following atomic weak decays, beta (b) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 microsecond are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the beta-decay of Re-187 and the EC of Ho-163. We show results obtained with detectors optimized for Re-187 and for Ho-163 experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted Ho-163 ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

Ranitzsch, P. C.-O.↗
DOE OSTI2020

Materials Data on Ho(SiNi)2 by Materials Project

Ho(NiSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Ho–Si bond lengths are 3.04 Å. Ni+2.50+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing NiSi4 tetrahedra. All Ni–Si bond lengths are 2.30 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Ho3+, four equivalent Ni+2.50+, and one Si4- atom. The Si–Si bond length is 2.40 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(NiB)2 by Materials Project

Ho(NiB)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ho3+ is bonded in a 6-coordinate geometry to six equivalent B3- atoms. There are a spread of Ho–B bond distances ranging from 2.69–2.88 Å. Ni+1.50+ is bonded in a 4-coordinate geometry to four equivalent B3- atoms. There are a spread of Ni–B bond distances ranging from 2.02–2.07 Å. B3- is bonded in a 8-coordinate geometry to three equivalent Ho3+, four equivalent Ni+1.50+, and one B3- atom. The B–B bond length is 1.74 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(SiAu)2 by Materials Project

Ho(AuSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho3+ is bonded to eight equivalent Si4- atoms to form HoSi8 hexagonal bipyramids that share corners with sixteen equivalent AuSi4 tetrahedra, edges with four equivalent HoSi8 hexagonal bipyramids, edges with eight equivalent AuSi4 tetrahedra, and faces with four equivalent HoSi8 hexagonal bipyramids. All Ho–Si bond lengths are 3.22 Å. Au+2.50+ is bonded to four equivalent Si4- atoms to form AuSi4 tetrahedra that share corners with eight equivalent HoSi8 hexagonal bipyramids, corners with four equivalent AuSi4 tetrahedra, edges with four equivalent HoSi8 hexagonal bipyramids, and edges with four equivalent AuSi4 tetrahedra. All Au–Si bond lengths are 2.56 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Ho3+, four equivalent Au+2.50+, and one Si4- atom. The Si–Si bond length is 2.29 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(IO3)3 by Materials Project

Ho(O3I)3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.29–2.77 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two I5+ atoms. There are one shorter (1.84 Å) and one longer (2.67 Å) O–I bond lengths. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ho3+ and one I5+ atom. The O–I bond length is 1.83 Å. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Ho3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ho3+ and two I5+ atoms. There are one shorter (1.85 Å) and one longer (2.85 Å) O–I bond lengths. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to one Ho3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three I5+ atoms. There are a spread of O–I bond distances ranging from 1.87–2.67 Å. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to one Ho3+ and one I5+ atom. The O–I bond length is 1.85 Å. There are three inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 6-coordinate geometry to six O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to four O2- atoms. In the third I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(Bi3O5)4 by Materials Project

Ho(Bi3O5)4 crystallizes in the cubic I23 space group. The structure is three-dimensional. Ho3+ is bonded to four equivalent O2- atoms to form HoO4 tetrahedra that share corners with twelve equivalent BiO5 square pyramids. All Ho–O bond lengths are 2.17 Å. Bi+3.08+ is bonded to five O2- atoms to form distorted BiO5 square pyramids that share corners with eight equivalent BiO5 square pyramids, a cornercorner with one HoO4 tetrahedra, and an edgeedge with one BiO5 square pyramid. There are a spread of Bi–O bond distances ranging from 2.10–2.55 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Bi+3.08+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Bi+3.08+ atoms. In the third O2- site, O2- is bonded to one Ho3+ and three equivalent Bi+3.08+ atoms to form corner-sharing OHoBi3 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(CuO2)2 by Materials Project

Ho(CuO2)2 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. Ho3+ is bonded in a 8-coordinate geometry to eight equivalent O2- atoms. There are four shorter (2.37 Å) and four longer (2.38 Å) Ho–O bond lengths. Cu+2.50+ is bonded in a square co-planar geometry to four equivalent O2- atoms. There is two shorter (1.90 Å) and two longer (1.92 Å) Cu–O bond length. O2- is bonded to two equivalent Ho3+ and two equivalent Cu+2.50+ atoms to form a mixture of distorted corner and edge-sharing OHo2Cu2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(AlC)3 by Materials Project

Ho(AlC)3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho3+ is bonded to six equivalent C4- atoms to form HoC6 octahedra that share corners with six equivalent AlC4 tetrahedra, edges with six equivalent HoC6 octahedra, and edges with six equivalent AlC4 tetrahedra. All Ho–C bond lengths are 2.54 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four C4- atoms to form AlC4 tetrahedra that share corners with three equivalent HoC6 octahedra, corners with seven equivalent AlC4 tetrahedra, and edges with three equivalent HoC6 octahedra. The corner-sharing octahedral tilt angles are 19°. There are one shorter (2.02 Å) and three longer (2.10 Å) Al–C bond lengths. In the second Al3+ site, Al3+ is bonded in a trigonal planar geometry to three equivalent C4- atoms. All Al–C bond lengths are 1.98 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to three equivalent Ho3+ and three equivalent Al3+ atoms. In the second C4- site, C4- is bonded to five Al3+ atoms to form corner-sharing CAl5 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(IO3)3 by Materials Project

Ho(O3I)3 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Ho3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ho–O bond distances ranging from 2.19–2.74 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and two I5+ atoms. There are one shorter (1.93 Å) and one longer (2.45 Å) O–I bond lengths. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Ho3+ and two equivalent I5+ atoms. Both O–I bond lengths are 2.80 Å. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ho3+ and two equivalent I5+ atoms. Both O–I bond lengths are 2.12 Å. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and one I5+ atom. The O–I bond length is 1.90 Å. There are two inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 6-coordinate geometry to six O2- atoms. In the second I5+ site, I5+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(BRu)4 by Materials Project

Ho(RuB)4 crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Ho3+ is bonded in a 12-coordinate geometry to twelve equivalent B3- atoms. There are a spread of Ho–B bond distances ranging from 2.95–3.22 Å. Ru+2.25+ is bonded to five equivalent B3- atoms to form a mixture of distorted corner and edge-sharing RuB5 trigonal bipyramids. There are a spread of Ru–B bond distances ranging from 2.15–2.29 Å. B3- is bonded in a 6-coordinate geometry to three equivalent Ho3+, five equivalent Ru+2.25+, and one B3- atom. The B–B bond length is 1.79 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(Co2B)6 by Materials Project

Ho(Co2B)6 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ho3+ is bonded in a hexagonal planar geometry to six equivalent B3- atoms. All Ho–B bond lengths are 3.03 Å. There are two inequivalent Co+1.25+ sites. In the first Co+1.25+ site, Co+1.25+ is bonded in a T-shaped geometry to three equivalent B3- atoms. There are one shorter (2.10 Å) and two longer (2.11 Å) Co–B bond lengths. In the second Co+1.25+ site, Co+1.25+ is bonded to four equivalent B3- atoms to form a mixture of distorted edge and corner-sharing CoB4 trigonal pyramids. There are two shorter (2.02 Å) and two longer (2.04 Å) Co–B bond lengths. B3- is bonded in a 7-coordinate geometry to one Ho3+ and seven Co+1.25+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(Ni2B)6 by Materials Project

Ho(Ni2B)6 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. Ho3+ is bonded in a distorted hexagonal planar geometry to six B3- atoms. There are a spread of Ho–B bond distances ranging from 2.96–3.29 Å. There are seven inequivalent Ni+1.25+ sites. In the first Ni+1.25+ site, Ni+1.25+ is bonded to four B3- atoms to form a mixture of edge and corner-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 1.98–2.09 Å. In the second Ni+1.25+ site, Ni+1.25+ is bonded in a 3-coordinate geometry to four B3- atoms. There are a spread of Ni–B bond distances ranging from 2.10–2.57 Å. In the third Ni+1.25+ site, Ni+1.25+ is bonded to four B3- atoms to form a mixture of distorted edge and corner-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 2.02–2.10 Å. In the fourth Ni+1.25+ site, Ni+1.25+ is bonded in a T-shaped geometry to three B3- atoms. There are two shorter (2.00 Å) and one longer (2.09 Å) Ni–B bond lengths. In the fifth Ni+1.25+ site, Ni+1.25+ is bonded in a distorted T-shaped geometry to three B3- atoms. There are one shorter (2.05 Å) and two longer (2.13 Å) Ni–B bond lengths. In the sixth Ni+1.25+ site, Ni+1.25+ is bonded in a T-shaped geometry to three B3- atoms. There are a spread of Ni–B bond distances ranging from 2.03–2.10 Å. In the seventh Ni+1.25+ site, Ni+1.25+ is bonded to four B3- atoms to form a mixture of edge and corner-sharing NiB4 tetrahedra. There are a spread of Ni–B bond distances ranging from 2.01–2.08 Å. There are four inequivalent B3- sites. In the first B3- site, B3- is bonded in a 7-coordinate geometry to one Ho3+ and seven Ni+1.25+ atoms. In the second B3- site, B3- is bonded in a 7-coordinate geometry to one Ho3+ and seven Ni+1.25+ atoms. In the third B3- site, B3- is bonded in a 7-coordinate geometry to one Ho3+ and seven Ni+1.25+ atoms. In the fourth B3- site, B3- is bonded in a 9-coordinate geometry to one Ho3+ and eight Ni+1.25+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho(ZnP)3 by Materials Project

Ho(ZnP)3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ho3+ is bonded to six equivalent P3- atoms to form HoP6 octahedra that share corners with six equivalent ZnP4 tetrahedra, edges with six equivalent HoP6 octahedra, and edges with six equivalent ZnP4 tetrahedra. All Ho–P bond lengths are 2.83 Å. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded in a trigonal planar geometry to three equivalent P3- atoms. All Zn–P bond lengths are 2.30 Å. In the second Zn2+ site, Zn2+ is bonded to four P3- atoms to form ZnP4 tetrahedra that share corners with three equivalent HoP6 octahedra, corners with seven equivalent ZnP4 tetrahedra, and edges with three equivalent HoP6 octahedra. The corner-sharing octahedral tilt angles are 14°. There are one shorter (2.40 Å) and three longer (2.47 Å) Zn–P bond lengths. There are two inequivalent P3- sites. In the first P3- site, P3- is bonded to three equivalent Ho3+ and three equivalent Zn2+ atoms to form PHo3Zn3 octahedra that share corners with three equivalent PHo3Zn3 octahedra, corners with three equivalent PZn5 trigonal bipyramids, and edges with nine equivalent PHo3Zn3 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second P3- site, P3- is bonded to five Zn2+ atoms to form PZn5 trigonal bipyramids that share corners with six equivalent PHo3Zn3 octahedra and corners with six equivalent PZn5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 69°.

36 MATERIALS SCIENCE↗