@book_section {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/57257, title ="Three-color resonance ionization spectroscopy of Zr in Si", author = "Hansen, C. S. and Calaway, W. F.", number = "388", pages = "215-218", month = "January", year = "1997", doi = "10.1063/1.52186 ", isbn = "1-56396-611-5", url = "https://resolver.caltech.edu/CaltechAUTHORS:20150506-085605768", note = "© 1997 American Institute of Physics.\n\nThis work is supported by the U.S. Department of Energy, BES-Material Sciences, under Contract W-31-109-ENG-38 and by NASA Grant NAGW-4182.", revision_no = "10", abstract = "It has been proposed that the composition of the solar wind could be measured directly by transporting ultrapure collectors into space, exposing them to the solar wind, and returning them to earth for analysis. In a study to help assess the applicability of present and future postionization secondary neutral mass spectrometers for measuring solar wind implanted samples, measurements of Zr in Si were performed. A three-color resonant ionization scheme proved to be efficient while producing a background count rate limited by secondary ion signal (5×10^(−4) counts/laser pulse). This lowered the detection limit for these measurements to below 500 ppt for 450,000 averages. Unexpectedly, the Zr concentration in the Si was measured to be over 4 ppb, well above the detection limit of the analysis. This high concentration is thought to result from contamination during sample preparation, since a series of tests were performed that rule out memory effects during the analysis.", } @book_section {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/57276, title ="A Comparison of Solar Wind and Estimated Solar System Xenon Abundances: A Test for Solid/ Gas Fractionation in the Solar Nebula", author = "Wiens, Roger C. and Burnett, D. S.", journal = "Proceedings of Lunar and Planetary Science", number = "22", pages = "153-159", month = "January", year = "1992", isbn = "0-942862-06-6", url = "https://resolver.caltech.edu/CaltechAUTHORS:20150506-120326624", note = "© 1992 Lunar and Planetary Institute, Houston.\n\nThis research was supported in part by NASA grants NAG 9-94 to D. Burnett and NAG 9-60 to R. O. Pepin. Reviews by K. Marti and an anonymous reviewer, and a discussion with P. Ryder, are acknowledged.", revision_no = "12", abstract = "Significant fractionation of dust/gas from the original interstellar cloud during the formation of the solar system is a distinct possibility. Identification of such an effect would provide important clues to nebular processes. Fractionation of volatiles is not constrained by CI abundances and only for the most abundant ones by photospheric observations. The solar Xe elemental abundance is determined here via solar wind measurements from lunar ilmenites and normalized to Si by spacecraft data. The results are compared with estimated abundances assuming no fractionation, which are relatively well constrained\nfor Xe by s-process calculations, odd-mass abundance interpolations, and odd-even abundance systematics.\nWhen corrected for solar wind/photospheric fractionation, the ^(130)Xe abundance given by surface layer oxidation of ilmenite from soil 71501, exposed within the last - 200 m.y., is 0.24 ± 0.09 normalized to Si = 10^6. This is indistinguishable from the estimates made assuming no solid/gas fractionation. A similar result was obtained for Kr by Wiens et al (1991). Results from breccia 79035 ilmenite, exposed at least ~1 Gy ago, indicate that the solar wind Xe flux may have been significantly higher relative to other noble gases, perhaps due to more efficient Xe ionization. If this is true, fluxes of C and S, which have similar first ionization potentials to Xe, should also be higher in the ancient solar wind from the\nsame time period, though such variations have not been observed.", } @book_section {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/57281, title ="Resonance ionization of sputtered atoms-progress toward a quantitative technique", author = "Calaway, W. F. and Coon, S. R.", journal = "Institute of Physics Conference Series", volume = "128", pages = "271-274", month = "January", year = "1992", issn = "0951-3248", isbn = "0-7503-0230-5", url = "https://resolver.caltech.edu/CaltechAUTHORS:20150506-130239979", note = "© 1992 IOP Publishing Ltd and individual contributors. \n\nWork supported by the U.S. Department of Energy, BES-Materials Sciences, under Contract W-31-109-ENG-38.", revision_no = "24", abstract = "The combination of RIMS and ion sputtering has been heralded as the ideal means of quantitatively probing the surface of a solid. While several laboratories have demonstrated the extreme sensitivity of combining RIMS with sputtering, less effort has been devoted to the question of accuracy. Using the SARISA instrument developed at Argonne National Laboratory, a number of well-characterized metallic\nsamples have been analyzed. Results from these determinations have been compared with data obtained by several other analytical methods. One significant finding is that impurity measurements down to ppb levels in metal matrices can be made quantitative by employing polycrystalline metal foils as calibration standards. This discovery substantially reduces the effort required for quantitative analysis since a single standard can be used for determining concentrations spanning nine orders of magnitude.", } @book_section {CaltechAUTHORS_https://authors.library.caltech.edu/id/eprint/36742, title ="Energy-mass distributions in induced fission", author = "Plasil, F. and Burnett, D. S.", pages = "1099-1100", month = "April", year = "1964", url = "https://resolver.caltech.edu/CaltechAUTHORS:20130201-112108067", note = "© 1964 Centre National de la Recherche Scientifique.\nDOE Contract Number:\tW-7405-ENG-48", revision_no = "22", abstract = "Measurements of the energy and mass distributions of fission fragments produced by the bombardment of a number of relatively light elements with heavy ions and alpha particles are presented. The results have been interpreted in terms of an approximate version of the liquid drop model which applies to this region of elements. The energies of both fission fragments from every event considered have been measured with solid state detectors, recorded in a correlated manner, and transformed to give mass-total kinetic energy density-of-events distributions. In some cases, data at several bombarding energies have been obtained. Comparisons with liquid drop calculations were made and good agreement was found in the gross features of the distributions, and in the nuclear temperature dependence of the widths.", }