Investigation of the structure of radiation damage in lithium-diffused silicon Final report, 3 Feb. - 8 Dec. 1969
Effects of electron irradiation on lithium-doped silicon
Corelli, J. C.↗
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Recent Observations of Cosmic Gamma Rays from 10 Mev to 1 Gev
Recent observations of cosmic gamma-rays made subsequent to the discovery of energetic photons from the galactic plane are analyzed. Three main areas under current investigation are treated. They are: (1) gamma ray emission from the plane of the galaxy, with emphasis on observations made in the vicinity of the galactic center, (2) gamma ray emission from the Crab nebula and its pulsar, and (3) diffuse gamma radiation.
Share, G. H.↗
Mechanisms for Production of the Diffuse Gamma-ray Continuum Radiation
The production of cosmic gamma radiation from Compton interactions with low energy photons, bremsstrahlung interactions, cosmic ray induced neutral pion production, and matter-antimatter annihilation is discussed.
Stecker, F. W.↗
Evidence for an interstellar or interplanetary source of diffuse He I 584 A radiation.
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Paresce, F.↗
Recent observations of cosmic gamma-rays from 10 MeV to 1 GeV
Recent observations of cosmic gamma rays made subsequent to the discovery of energetic protons from the galactic plane are discussed. The main areas covered include: (1) gamma ray emission from the plane galaxy, with emphasis on observations made in the vicinity of the galactic center, (2) gamma ray emission from the Crab nebula and its pulsar, and (3) diffuse gamma radiation.
Share, G. H.↗
Stagnation and downstream viscous shock-layer solutions with radiation and coupled ablation injection
This paper describes a rigorous viscous shock-layer analysis for investigating high energy equilibrium flow fields about blunt axisymmetric bodies. The analysis includes radiation transfer, mass injection, diffusion, and viscous effects. Radiation transfer is calculated with a nongray radiation model that accounts for line and continuum radiation. The analysis can treat all levels of blowing for both stagnation and downstream flow. Results are presented for selected earth entry conditions that demonstrate the essential features of this analysis. Particular emphasis is given to the effects of mass injection on stagnation and downstream flow. Results for both specified and coupled ablation injection are presented.
Moss, J. N.↗
Mass absorption coefficients of Parylene N at soft X-ray and vacuum-ultraviolet wavelengths
Parylene N was selected as a bandpass filter for the extreme-ultraviolet telescope, flown on the Apollo-Soyuz Test Project in July 1975. The telescope measures stellar and diffuse cosmic radiation in the wavelength region from 45 to 170 A. In connection with this application, a systematic study was conducted of the mass absorption coefficient of the Parylene N. The results of the study for the wavelength region from 44 to 2536 A are reported.
Stern, R.↗
Far-infrared observations of NGC 7027
Far-infrared observations of the planetary nebula NGC 7027 show that its total infrared flux is 2.4 by 10 to the -10th power W/sq m, approximately one-third of which is emitted in each of the intervals from 1 to 17, 17 to 30, and 30 to 300 microns. Sufficient energy to account for the corresponding infrared luminosity of 23,000 times the solar value at 1.77 kpc is available as diffuse nebular radiation or from moderate competition between dust and gas for Lyman continuum photons. Most of the infrared flux arises from a source comparable in size to the H II region. The flux at wavelengths greater than 17 microns can be attributed to grains with temperatures not exceeding 120 K and total mass such that the gas-to-dust ratio is close to the lower limit allowed by cosmic abundances.
Telesco, C. M.↗
Prediction of moisture and temperature changes in composites during atmospheric exposure
The effects of variations in diffusion coefficients, surface properties of the composite, panel tilt, ground reflection, and geographical location on the moisture concentration profiles and average moisture content of composite laminates were studied analytically. A heat balance which included heat input due to direct and sky diffuse solar radiation, ground reflection, and heat loss due to reradiation and convection was used to determine the temperature of composites during atmospheric exposure. The equilibrium moisture content was assumed proportional to the relative humidity of the air in the boundary layer of the composite. Condensation on the surface was neglected. Histograms of composite temperatures were determined and compared with those for the ambient environment.
Tompkins, S. S.↗
The phase diagram and transport properties for hydrogen-helium fluid planets
The properties of pure hydrogen and helium are examined, taking into account metallic hydrogen, molecular hydrogen, and the molecular-metallic transition. Metallic hydrogen-helium mixtures are considered along with molecular hydrogen-helium mixtures, the total phase diagram, and minor constituents, including deuterium. The transport properties of the metallic and the molecular phase are also discussed, giving attention to electrical conductivity, thermal conductivity, viscosity, self-diffusion, interdiffusion, radiative opacity, and second-order transport coefficients.
Stevenson, D. J.↗
Geomagnetic field fluctuations at synchronous orbit. II - Radial diffusion
Power spectra of geomagnetic-field variations measured at synchronous equatorial altitude (geomagnetic shell parameter about 6.6) in the magnetosphere are used to calculate the time dependence of the radial diffusion coefficient for particles in the radiation belts. The diffusion coefficients calculated are mainly applicable for relativistic electrons. The magnitudes of the derived diffusion coefficients using data only from local day observations are consistent with those reported from analyses of most particle observations and thus are slightly larger than those derived from magnetic sudden commencements. They are consistent with the diffusion coefficients calculated from power spectra of ground-based geomagnetic data measured near L = 4.
Lanzerotti, L. J.↗
Observations of diffuse galactic gamma rays
The observations of galactic diffuse gamma radiation are reviewed. The connections of the gamma ray observations with galactic structure and cosmic rays are discussed. The high latitude galactic component and the low latitude emission from the galactic plane are examined. The observations in other regions of the gamma ray spectrum are discussed.
Simpson, G. A.↗
The significance of gamma ray observations for neutrino astronomy
X-ray, gamma ray and neutrino observations are examined to show, in a general way, the relationship between them. Existing gamma ray measurements are summarized and some examples are used to set ranges or limits for neutrino fluxes for specific types of models. The purpose of this is to show the possibilities for separation between models and to aid in the consideration of neutrino detector designs. Attention is given to exceptional and normal galaxies, as well as to compact objects, and diffuse isotropic radiation. It is noted that the close relationship between gamma rays and neutrino production will be useful for future neutrino astronomy.
Fichtel, C. E.↗
Observations of diffuse galactic gamma rays
Observations of 35 MeV to several GeV diffuse gamma radiation from the galaxy are available from the SAS-2 and COS-B instruments. This paper gives a brief review of the experimental problem, a discussion of the high-latitude (local) galactic component, and a study of the more distant low-latitude emission from the galactic plane. Finally, the emerging observations in other energy ranges are mentioned.
Simpson, G. A.↗
Calculating Atmospheric Effects in Satellite Imagery
Report presents detailed analysis of atmospheric blurring inherent in photographs or other observations of Earth from satellites or aircraft. Blurring result of scattering of radiation, which diffuses sharp image features by causing light from one part of scene to fall on image of adjacent part. In contrast with earlier approaches to atmospheric optics, one presented in report more accurate and versatile and designed for use on minicomputers.
Diner, D. J.↗
A Sphere-Scanning Radiometer for Rapid Directional Measurements of Sky and Ground Radiance: the PARABOLA Field Instrument
A unique field instrument, called the PARABOLA, a collapsable support boom, which is self contained and easily transportable to remote sites to enable the acquisition of radiance data for almost the complete (4 pi) sky and ground-looking hemispheres in only 11 seconds was designed. The PARABOLA samples in 15 deg instantaneous field of view sectors in three narrow bandpass spectral channels simultaneously. Field measurement on a variety of earth surface cover types using a truck boom, a specially designed pickup truck mounting system, and a hot air balloon were studied. The PARABOLA instrument has potential for climatological and other studies which require characterization of the distribution of diffuse solar radiation within the sky hemisphere.
Deering, D. W.↗
Effect of Scattering on Instabilities in Line-driven Stellar Winds
Line driven O-B stellar winds are unstable to perturbations of short spatial wavelength and the growth rates for such instabilities are very rapid. The nature of the nonlinear development of this instability is unknown, but might possibly be one of blobs of gas driven through ambient gas or a quasiregular train of outward moving shocks. In either case the resulting dissipation of mechanical energy might explain the observed anomalous heating n O-B stars as evidenced by their X-ray emission and high ionization state. It also might explain the observed fine structure of the absorption lines and their time variability. The driving due to the absorption of the stellar continuum flux was considered and the effects of the diffuse, scattered radiation field were neglected. It was shown that under certain special conditions the effect of scattering could reduce the instability growth rate to zero. A stability analysis that includes scattering, but that uses the more physically realistic assumption of complete redistribution instead of coherent scattering, and that includes the effects of transverse velocity gradients, which become important as the flow moves away from the stellar surface is presented. It is found that the instability is eliminated right at the base of the wind, but that as the flow moves outward the instability rate rapidly becomes equal to a substantial fraction of the calculated value, the fraction asymptotically reaching 80% at large radii. Since this still implies many e folds in a characteristic outflow time, the primary conclusion that these winds are highly unstable is unchanged.
Owocki, S. P.↗