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79 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on SmThB12 by Materials Project

ThSmB12 is Calcium hexaboride-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Th4+ is bonded in a 1-coordinate geometry to twenty-four equivalent B+0.50- atoms. All Th–B bond lengths are 3.02 Å. Sm2+ is bonded in a 1-coordinate geometry to twenty-four equivalent B+0.50- atoms. All Sm–B bond lengths are 3.02 Å. B+0.50- is bonded in a 1-coordinate geometry to two equivalent Th4+, two equivalent Sm2+, and five equivalent B+0.50- atoms. There is one shorter (1.63 Å) and four longer (1.76 Å) B–B bond length.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba3NaB24 by Materials Project

NaBa3B24 is Calcium hexaboride-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Na is bonded in a 1-coordinate geometry to twenty-four B atoms. There are sixteen shorter (3.10 Å) and eight longer (3.12 Å) Na–B bond lengths. There are two inequivalent Ba sites. In the first Ba site, Ba is bonded in a 12-coordinate geometry to twenty-four B atoms. There are a spread of Ba–B bond distances ranging from 3.10–3.18 Å. In the second Ba site, Ba is bonded in a 1-coordinate geometry to twenty-four B atoms. All Ba–B bond lengths are 3.13 Å. There are six inequivalent B sites. In the first B site, B is bonded in a 1-coordinate geometry to two equivalent Na, two equivalent Ba, and five B atoms. There are a spread of B–B bond distances ranging from 1.72–1.79 Å. In the second B site, B is bonded in a 1-coordinate geometry to four Ba and five B atoms. There is one shorter (1.74 Å) and four longer (1.78 Å) B–B bond length. In the third B site, B is bonded in a 1-coordinate geometry to four equivalent Ba and five B atoms. The B–B bond length is 1.74 Å. In the fourth B site, B is bonded in a 1-coordinate geometry to four equivalent Ba and five B atoms. The B–B bond length is 1.74 Å. In the fifth B site, B is bonded in a 1-coordinate geometry to four equivalent Ba and five B atoms. In the sixth B site, B is bonded in a 1-coordinate geometry to four equivalent Na and five B atoms. The B–B bond length is 1.67 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HgB6 by Materials Project

Hg(B)6 is Calcium hexaboride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional and consists of one mercury molecule and one B framework. In the B framework, B is bonded in a 5-coordinate geometry to five equivalent B atoms. There is one shorter (1.68 Å) and four longer (1.78 Å) B–B bond length.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CeEuB12 by Materials Project

EuCeB12 is Calcium hexaboride-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Eu3+ is bonded in a 1-coordinate geometry to twenty-four B+0.50- atoms. All Eu–B bond lengths are 3.05 Å. Ce3+ is bonded in a 1-coordinate geometry to twenty-four B+0.50- atoms. All Ce–B bond lengths are 3.05 Å. There are two inequivalent B+0.50- sites. In the first B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to two equivalent Eu3+, two equivalent Ce3+, and five B+0.50- atoms. There is one shorter (1.66 Å) and four longer (1.76 Å) B–B bond length. In the second B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to two equivalent Eu3+, two equivalent Ce3+, and five B+0.50- atoms. There is one shorter (1.66 Å) and two longer (1.76 Å) B–B bond length.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on YbTmB12 by Materials Project

YbTmB12 is Calcium hexaboride-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Yb3+ is bonded in a 1-coordinate geometry to twenty-four equivalent B+0.50- atoms. All Yb–B bond lengths are 3.01 Å. Tm3+ is bonded in a 1-coordinate geometry to twenty-four equivalent B+0.50- atoms. All Tm–B bond lengths are 3.01 Å. B+0.50- is bonded in a 1-coordinate geometry to two equivalent Yb3+, two equivalent Tm3+, and five equivalent B+0.50- atoms. There is one shorter (1.64 Å) and four longer (1.74 Å) B–B bond length.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaGdB12 by Materials Project

GdLaB12 is Calcium hexaboride-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Gd3+ is bonded in a 1-coordinate geometry to twenty-four B+0.50- atoms. All Gd–B bond lengths are 3.04 Å. La3+ is bonded in a 8-coordinate geometry to twenty-four B+0.50- atoms. All La–B bond lengths are 3.04 Å. There are three inequivalent B+0.50- sites. In the first B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to two equivalent Gd3+, two equivalent La3+, and five B+0.50- atoms. There is one shorter (1.65 Å) and four longer (1.76 Å) B–B bond length. In the second B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to four equivalent La3+ and five B+0.50- atoms. The B–B bond length is 1.65 Å. In the third B+0.50- site, B+0.50- is bonded in a 1-coordinate geometry to four equivalent Gd3+ and five B+0.50- atoms. The B–B bond length is 1.64 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2021

The Madison plasma dynamo experiment: A facility for studying laboratory plasma astrophysics

The Madison plasma dynamo experiment (MPDX) is a novel, versatile, basic plasma research device designed to investigate flow driven magnetohydrodynamic instabilities and other high-β phenomena with astrophysically relevant parameters. A 3 m diameter vacuum vessel is lined with 36 rings of alternately oriented 4000 G samarium cobalt magnets, which create an axisymmetric multicusp that contains ∼14 m3of nearly magnetic field free plasma that is well confined and highly ionized (>50%). At present, 8 lanthanum hexaboride (LaB6) cathodes and 10 molybdenum anodes are inserted into the vessel and biased up to 500 V, drawing 40 A each cathode, ionizing a low pressure Ar or He fill gas and heating it. Up to 100 kW of electron cyclotron heating power is planned for additional electron heating. The LaB6cathodes are positioned in the magnetized edge to drive toroidal rotation through J × B torques that propagate into the unmagnetized core plasma. Dynamo studies on MPDX require a high magnetic Reynolds number Rm > 1000, and an adjustable fluid Reynolds number 10 1). Initial results from MPDX are presented along with a 0-dimensional power and particle balance model to predict the viscosity and resistivity to achieve dynamo action.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗