Center-limb observations of inhomogeneities in the solar atmosphere. I - The Mg b lines
Solar center-limb observations of line brightness and Doppler shift fluctuations for Mg b lines
Cannon, C. J.↗
SEARCH · Engineering Papers
Results for “Mg”
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.
Spectra of Mg IX, Al X, and Si XI isoelectronic with Be I
Mg, Al and Si ions spectral analysis, discussing energy levels and transition lines
Behring, W.↗
Spectra of Fe, Co, Ni, and Cu isoelectronic with Na I and Mg I
Highly ionized line spectra of Fe, Co, Ni and Cu belonging to Na I and Mg I isoelectronic sequences
Behring, W.↗
Absolute oscillator strengths for some resonance multiplets of Ca I,II, Mg I,II, B I, and Al I
Ca, Mg, B and Al prominent resonance transitions radiative lifetimes and absolute oscillator strengths
Liszt, H. S.↗
Thermodynamic properties of Mg-Ge alloys
Mg-Ge alloys liquid and two phase mixtures thermodynamic properties at 660-1130 C, using galvanic cell with magnesium chloride electrolyte
Belton, G. R.↗
Alpha-gamma angular correlations in C 12, Mg 24, Ni 58, and Sn 120
Inelastic scattering alpha-gamma angular correlations from C 12, Mg 24, Ni 58 and Sn 120 decay measurements
Baron, N.↗
Low keV electron probe analysis of silicate minerals for Mg, Al, and Si using pure-element standards
Accurate electron probe values for Mg, Al, and Si in silicate minerals may be obtained with pure-element standards. Analysis must be done at low (6 kV) accelerating potential and for best results, the average atomic number of the sample should be within about plus or minus 1 of the atomic number of the pure-element standard. This last requirement is automatically fulfilled for most common silicate minerals, as their average atomic numbers usually fall within the 11 to 15 range. Examples studied include a wet-chemically analyzed cordierite containing 17.71 weight percent Al, for which a value of 17.6 plus or minus 0.3 percent was obtained with the electron probe, and a hornblende containing 19.15 percent Si, which gave 19.0 plus or minus 0.3 percent using the probe method.
Cunningham, G. G.↗
Excitation of Mg/+/ by electron collisions.
Demonstration that the Mg II resonance doublet at 2800 A represents a suitable diagnostic tool for the study of physical conditions in the solar chromosphere. The interpretation of intensities and line profiles requires the knowledge of all electron collision cross sections, which can affect directly or indirectly the population of upper levels of the doublet. For this purpose collision cross sections for transitions between levels 3s, 4s, 5s, 6s, 3p, 4p, 5p, 3d, 4d, and 5d have been calculated in the unitarized Coulomb-Born approximation without exchange. For the 3s-3p and 3s-3d transitions the present results are in a good agreement with the close-coupling calculations of Burke and Moores (1968).
Blaha, M.↗
Mg and Be ion implanted GaAs.
Description of methods for generating desired Be and Mg ions and producing the electrical properties of p-type layers by implanting these ions in GaAs substrates. It is shown that the p-type layers thus produced have large hole concentrations and mobilities.
Hunsperger, R. G.↗
GaAs transistors formed by Be or Mg ion implantation
N-p-n transistor structures have been formed in GaAs by implanting n-type substrates with Be ions to form base regions and then implanting them with 20-keV Si ions to form emitters. P-type layers have been produced in GaAs by implantation of either Mg or Be ions, with substrate at room temperature, followed by annealing at higher temperatures.
Hunsperger, R. G.↗
Line profiles and turbulence generated by acoustic waves in the solar chromosphere. II - Contours of the Ca II and Mg II K lines
Making use of the time-averaged absorption profiles derived by Oster and Ulmschneider, non-LTE line formation in the context of a two-level atom is investigated for an isothermal atmosphere and for the Ca II and Mg II K lines in the solar chromosphere as represented by the Harvard-Smithsonian Reference Atmosphere. Source functions and emergent line profiles are computed for a variety of assumptions concerning the acoustically broadened profiles and the solar velocity fields.
Shine, R. A.↗
High-spectral-resolution measurements of the H I 1216 and Mg II 2800 emissions from Arcturus
High-spectral-resolution scans of H I 1216 and Mg II 2796, 2803 obtained using the ultraviolet spectrometer abroad the Copernicus satellite show broad and very asymmetrical emission profiles. The ratio of the line widths to the solar values is consistent with a law similar to the Wilson-Bappu relation for the calcium K reversal. A fit of the interstellar absorption profile indicates that the average H density toward this nearby star is low, 0.02-0.1 per cu cm.
Moos, H. W.↗
A possible width-luminosity correlation of the Ca II K1 and Mg II k1 features
Existing high resolution stellar profiles of the Ca II and Mg II resonance lines suggest a possible width-luminosity correlation of the K1 minimum features. It is shown that such a correlation can be simply understood if the continuum optical depth of the stellar temperature minimum is relatively independent of surface gravity as suggested by three stars studied in detail.
Ayres, T. R.↗
Resonance line transfer with partial redistribution. III Mg II resonance lines in solar-type stars
We discuss the gravity dependence of the Mg II resonance lines calculated with inclusion of effects of partial redistribution in frequency. Using chromospheric models scaled from a solar model, we demonstrate the increased decoupling of the radiation temperature of the k1 feature from the minimum electron temperature in lower-gravity models. The limb darkening of the k-line in the main-sequence model is also discussed.
Milkey, R. W.↗
The Mg II h and k lines. II - Comparison with synthesized profiles and Ca II K
Measured high-dispersion center and limb profiles of the solar Mg II h and k resonance lines are compared with synthetic spectra computed with a partial-redistribution formalism and based on several upper-photosphere and lower-chromosphere temperature distributions. Profiles of the analogously formed Ca II K resonance line are also synthesized for the same atmospheric models. The spectrum-synthesis approach is outlined, and the collisional and fixed radiative rates appropriate to the adopted model atoms and solar atmosphere are discussed. It is found that the HSRA and VAL models predict systematically lower intensities in the h, k, and K inner wings than observed and that models with a somewhat higher minimum temperature (about 4450 K) can reproduce the measured inner wings and limb darkening. A 'Ca II' solar model with a minimum temperature of 4450 K is proposed as an alternative to the class of models based on continuum observations.
Ayres, T. R.↗
Variations in the ultraviolet Mg II lines of beta Persei
Copernicus satellite observations have been used to study changes in the Mg II lines in the neighborhood of 2800 A in Algol during eclipse. The resonance lines near 2800 A show doubling near the bottom of primary eclipse. A possible explanation is that emission from component B fills the line centers; the absolute magnitude thus derived for component B agrees with other values in the literature.
Chen, K.-Y.↗
Fe and Mg in plagioclase
Distribution coefficients for Fe and Mg between plagioclase and basaltic liquids were measured for lunar, terrestrial and synthetic systems. The data obtained imply that lunar anorthosites crystallized from relatively iron-rich liquids, that Fe/Mg zoning in plagioclase is an indicator of crystallization processes in basaltic magmas, and that Fe/Mg heterogeneity in plagioclase is a clue to the recognition of impact melts.
Longhi, J.↗
Faint emission features in the Mg II resonance-line wings
Data obtained with a rocket-borne echelle spectrograph are presented which indicate the presence of three faint emission features deep in the cores of the Mg II h and k resonance-line wings in the solar Fraunhofer spectrum. Results of wavelength measurements are discussed, and the relative intensities of the emission features are examined. It is tentatively suggested that the first feature be identified with the Fe II line at 2797.037 A, the second feature is probably the V II line at 2803.469 A, and the third feature may originate in Fe II emission at 2804.021 A. Possible emission mechanisms are proposed, and it is concluded that the detected features may be of potential diagnostic value for the analysis of depth variations of temperature and velocity in the lower chromosphere as well as for solar and possibly stellar spectroscopy.
Allen, M. S.↗