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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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Cosmic ray produced radionuclides and rare gas isotopes from Saint-Severin meteorite surface, showing relative Kr spallation mass yields dependence on cosmic ray energy spectra
Induced radionuclides in muscle tissues of astronauts by cosmic rays
Apollo 11 lunar rock and fines primordial radionuclide abundances and concentration gradients by gamma ray spectrometry at Lunar Receiving Laboratory
Cosmogenic and primordial radionuclides in Apollo 11 lunar soil and rocks, using nondestructive gamma ray spectral measurements
Apollo 11 lunar rock and soil bombardment produced radionuclide patterns, discussing solar flare protons and alphas, age determination and astronomical models
Measurement of radiation exposure of Apollo 7, 8, 9, and 10 astronauts by determination of radionuclide content of feces and urine
Lost City /Oklahoma/ and Ucera /Venezuela/ meteorites cosmogenic radionuclides data, using nondestructive analysis by gamma-gamma-coincidence counting system
Radionuclides and noble gas isotopic abundances in recently fallen meteorites for cosmic ray exposure ages estimates
Cosmic ray produced radionuclides in Lost City meteorite, determining concentrations by nondestructive two-parameter gamma ray analysis
Primordial radionuclides K, Th and U concentrations in Apollo 12 lunar rocks, breccias and fines, using gamma ray spectrometry
Lunar cosmogenic radionuclides production time and spatial dependence calculations, comparing Apollo 11 and 12 measurements
Cosmogenic radionuclide concentration and exposure ages of Apollo 12 rock from Ocean of Storms
Lunar surface erosion and mixing from cosmogenic and primordial radionuclide measurement in Apollo 12 lunar rock and soil samples
Cosmogenic and primordial radionuclides in Apollo 12 surface rocks and fines from nondestructive gamma ray spectrometry
Two basalts, two breccias, and two soils from Apollo 15 were analyzed by nondestructive gamma-ray spectrometry. The concentrations of potassium, thorium, and uranium in the basalts were similar to those in the Apollo 12 basalts, but the potassium:uranium ratios were somewhat higher. Primordial radioelements were enriched in the soils and breccia, consistent with a two-component mixture of mare basalt and up to 20 percent foreign component (KREEP). The abundance patterns for cosmogenic radionuclides implied surface sampling for all specimens. The galactic cosmic-ray production rate of vanadium-48 was determined as 57 (plus or minus 11) disintegrations per minute per kilogram of iron. Cobalt-56 concentrations were used to estimate the intensity of the solar flare of January 25, 1971.
Throium, uranium, potassium, aluminium-26, and sodium-22 were measured by nondestructive gamma ray spectrometry in six soil and two rock samples gathered by Apollo 16 in the lunar central highlands. The soil samples probably include both major geologic formations in the vicinity, the Cayley and Descartes Formations, although it is possible that the Descartes Formation is not represented. The rock samples have low concentrations of primordial radionuclides. The Al concentrations were lower than could be expected from the high abundance of alumina in the Apollo 16 soils reported earlier, but this could be due to lower concentrations of target elements in these soils, sampling depth variations, or regolithic mixing (exposure age variations).
A device has been constructed and tested which provides immediate readout of bone mineral content and bone width from absorptiometric scans with low energy radionuclides. The basis of this analog system is a logarithmic converter-integrator coupled with a precision linear ratemeter. The system provided accurate and reliable results on standards and ashed bone sections. Clinical measurements were made on about 100 patients with the direct readout system, and these were highly correlated with the results from digital scan data on the same patients. The direct readout system has been used successfully in field studies and surveys as well as for clinical observations.
Natural and cosmic ray induced radionuclides have been determined in 15 rocks and 7 soils from the Apollo 17 mission by nondestructive gamma-ray spectroscopy. The Th and K contents of these rocks and soils are shown to be linear functions of the U contents. Large amounts of Co-56, Sc-46, and Mn-54 were found in these samples due to the large proton-accelerating flares which occurred between August 2 and 6, 1972. The behavior of the Co-56 activity as a function of the Mn-54 activity seems to be the result of variation in surface to volume ratios among the samples and exposure angle. It is not necessary to invoke an asymetric solar flare flux to explain this behavior.