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Title: Discrimination and quantification of contamination and implanted solar wind in Genesis collector shards using grazing incidence synchrotron x-ray techniqies: Initial results

Grazing incidence X-ray fluorescence is a non-destructive technique that can differentiate the embedded solar wind component from surface contamination and collector background in the Genesis shards. Initial solar Fe abundance in D30554 is 8 x 10{sup 12}/cm{sup 2}. Accurate knowledge of the composition of the Sun provides a baseline, which allows an understanding of how the solar system has evolved over time and how solar processes and solar wind mechanics behave. Unfortunately, the errors in photospheric abundances are too large for many planetary science problems and this hampers our understanding of these different processes. Analyses of solar wind implanted in meteorites or lunar soils have provided more precise data but alteration processes on these bodies may complicate such information. In response to this need for pristine solar wind samples, NASA developed and launched the Genesis Probe. Unfortunately, the probe smashed into the Utah desert shattering the 300 collector plates into 15,000+ pieces all of which are now coated in a both a fine terrestrial dust and Si and Ge powder from the disrupted collectors themselves. The solar wind penetration depth is 100-200 nm and the superposed contamination layers are typically 40-50 nm. Stringent cleaning regimes have the potential of removingmore » the solar wind itself. The best solution is to have sufficient spatial resolution to separately analyze the surface contamination and penetrated solar wind. To that end, three Genesis collector array shards and their appropriate flight spares were characterized via grazing incidence x-ray fluorescence and x-ray reflectivity. The goals were (1) to evaluate the various cleaning methods used to eliminate contamination, (2) to identify the collector substrates most suited for this technique, (3) to determine whether the solar wind signature could be deconvolved from the collector background signature, and (4) to measure the relative abundances of Ca to Ge in the embedded solar wind.« less
Authors:
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  1. (CIT)
  2. (
Publication Date:
OSTI Identifier:
1008980
Resource Type:
Conference
Resource Relation:
Conference: Lunar and Planetary Science XXXVII;March 13-17, 2006;Houston, Texas
Publisher:
Lunar and Planetary Science XXXVII;LPI;1451-1451
Research Org:
Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
ENGLISH
Subject:
43 PARTICLE ACCELERATORS; ABUNDANCE; CLEANING; CONTAMINATION; DUSTS; FLUORESCENCE; FRAGMENTATION; METEORITES; NASA; ORIGIN; PENETRATION DEPTH; PLATES; PROBES; REFLECTIVITY; SOILS; SOLAR SYSTEM; SOLAR WIND; SPATIAL RESOLUTION; SUBSTRATES; SURFACE CONTAMINATION; SYNCHROTRONS