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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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Space environment simulation tests to determine neutral charge low energy particle irradiation effects on spacecraft aluminum and zinc thermal control coatings
Proton irradiation effects on minority carrier lifetime in silicon and gallium arsenide semiconductor materials
Daily freezing, thawing cycles, and ultraviolet irradiation effects on bacteria survival
Proton irradiation effects on epithelial duodenum cells of mice
Minimal angle of resolution /MAR/ between point and extended circular source and between point source and simulated horizon, studying irradiation effects on manual navigation
Fast neutron irradiation effect on niobium nitride current carrying capacity, showing enhancement
Proton irradiation effects on current degradation at fixed voltages of silicon solar cells with coverslips
Whole body X irradiation effect on protein degradation in mice, using radioactive I labeled albumin
Irradiation effects on semiconductor properties, luminescence, and p-i-n diode electrical properties
Electron paramagnetic resonance of Mn ions in single crystal and powder forsterite, testing heat treatment and proton irradiation effect on ordering
Lithium-diffused silicon, investigating heat treatment and electron irradiation effects on electrical resistivity at high temperatures
Irradiation effects on polyethylene and fiber glass reinforced epoxy capsules
High intensity neutron irradiation effects on physical properties of solids determined by underground nuclear explosions
Radiation facility and equipment for studying Sr-90 electron irradiation effects in Li-doped silicon
The irradiation effects of 22 MeV protons on the electrical characteristics of GaAs continuous-wave Gunn oscillators was studied. The radio frequency power output was reduced by 3 decibels at proton fluences in the neighborhood of 1.5 x 10 to the 12th power protons/sq cm. Conductance measurements indicate that the carrier removal rate at high electric fields remained roughly 40 percent less than at low fields. Diode efficiencies of two device groups were found to be monotonically descreasing functions of fluence. Frequency modulation noise was generally unaffected by radiation, but the magnitude of the noise in the noise power spectrum increased significantly. These effects are partially accounted for, in a qualitative fashion, by a model of electron traps having field-dependent net-carrier capture rates and various response times.
The charge dissipation mechanism of silica fabrics and silica fabric/Aluminum composites was studied by means of various sample configurations tested under monoenergetic electron beams at energies between 5 and 20 keV. Grounding of the aluminum rear face of the composite is necessary in order to ensure a good electrostatic performance. The surface potentials are dependent on the flux rate in the range 10 pA -cm(2-) to 3 nA cm(-2); they are the highest at the lowest flux rate. Strong discharges have been evidenced at 20 keV but do not occur under 15 keV electrons. A substantial decrease in the surface potential of the sample is observed every time that an irradiation by low energy electrons ( 2 to 4 keV) is performed simultaneously with the irradiation by medium-energy electrons (10 to 20 keV). Silica fabrics and composites are very sensitive of contamination or contamination-plus-irradiation effects.
Topics discussed include studies of chondrites, mesosiderites, and achondrites; isotope modeling; Antarctic weathering; irradiation effects; lunar regolith studies; the Apollo 17 drill core; soils and agglutinates; and volatiles. Particular attention is given to the proportional retention of I and Xe-129 in preheated Allende, olivine clasts from mesosiderites and howardites as clues to the nature of achondritic parent bodies, a record of solar corpuscular radiation in minerals from lunar soils, the experimental shock metamorphism of lunar soil, and the clouding of pyroxene and plagioclase in eucrites.
Various topics in meteorology were discussed. Chondrites, comets, cosmic dust, irradiation effects, cosmic rays, achondrites, asteroids, and lunar crators were among the topics discussed.