Showing papers by "Charles L. Melcher published in 1982"
TL;DR: In this article, a correlation between TL sensitivity and glow curve shape is discussed, with the difference in the glow curve shapes of meteorite types 3.4 and less and type 3.5 and greater being tentatively attributed to an order disorder transition in plagioclase, the TL phosphor.
74 citations
01 Jan 1982
TL;DR: The diffusion properties of xenon implanted into feldspar, a major mineral in meteorites and lunar samples, are investigated in light of the importance of Xenon diffusion in the interpretation of early solar system chronologies and the retention time of solar-wind-implanted Xe.
Abstract: The diffusion properties of xenon implanted into feldspar, a major mineral in meteorites and lunar samples, are investigated in light of the importance of xenon diffusion in the interpretation of early solar system chronologies and the retention time of solar-wind-implanted Xe. Known doses of Xe ions were implanted at an energy of 200 keV into single-crystal plagioclase targets, and depth profiles were measured by alpha particle backscattering before and after annealing for one hour at 900 or 1000 C. The fraction of Xe retained following annealing is found to be strongly dependent on implantation dose, being greatest at a dose of 3 x 10 to the 15th ions/sq cm and decreasing at higher and lower doses. Xe retention is also observed to be unaffected by two-step anneals, or by implantation with He or Ar. Three models of the dose-dependent diffusion properties are considered, including epitaxial crystal regrowth during annealing controlled by the extent of radiation damage, the creation of trapping sites by radiation damage, and the inhibition of recrystallization by Xe during annealing
5 citations
TL;DR: In this article, the usefulness of an effective trap depth to approximate the group of closely spaced trap depths responsible for the low temperature thermoluminescence in meteorites is evaluated on the basis of its success when used with the TL equivalent dose method to determine terrestrial ages of Antarctic meteorites.