HR: 0800h
AN: SH31A-1185    [Abstracts]
TI: SARISA: an instrument for analysis of Genesis mission returned samples
AU: * Veryovkin, I V
EM: verigo@anl.gov
AF: Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 United States
AU: Calaway, W F
EM: wfcalaway@anl.gov
AF: Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 United States
AU: Tripa, C E
EM: tripa@anl.gov
AF: Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 United States
AU: Pellin, M J
EM: pellin@anl.gov
AF: Materials Science Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 United States
AU: Burnett, D S
EM: burnett@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, CALTECH, MC 100-23, Pasadena, CA 91125 United States
AB: To analyze elemental and isotopic composition of solar wind samples returned to Earth by the Genesis spacecraft of NASA's Discovery Program, a special advanced analytical instrument facility was constructed at Argonne National Laboratory. This facility is based on a new time-of-flight mass spectrometer and laser post-ionization of neutral species ion sputtered or laser desorbed from the solar wind collectors. The constructed instrument is called SARISA. It was specifically designed to efficiently use sample during laser post-ionization analysis. Since neutrals are the predominant species in ion sputtering and laser desorption, and laser post-ionization efficiently converts neutrals into ions, this instrument minimizes consumption of sample during analysis so that pieces of the collectors as small as 25 mm$^{2}$ can be characterized. This is very important for the precious solar wind samples. Also incorporated in the instrument is the capability for ultra-shallow depth profiling analysis with resolution of a few nanometers. This is accomplished by implementing a dual beam technique, which includes low-energy normal-incidence ion bombardment for removing atomic monolayers from the sample surface and micro-focused ion or laser beams for generating secondary neutrals from the exposed surface in order to probe the sample composition. The lateral resolution of the probe beams is 50 nm for ions from a liquid-metal ion source and 0.6 $\mu$m for photons from a desorption laser. Built into SARISA are an in-vacuum all-reflecting optical microscope and a capability of secondary electron imaging using a dedicated detector. The imaging capabilities of SARISA will allow identification of particulate contaminants on the collector surface in order to perform analysis on uncontaminated regions of this surface. Small sample consumption, high analysis resolution and imaging capabilities all are particularly important features of the SARISA instrument because of the condition of the returned Genesis samples. Details of the instrument design and results from test samples will be presented. This work is supported by the U. S. Department of Energy, BES-Materials Sciences, under Contract W-31-109-ENG-38, and by NASA under Work Orders W-19,895 and W-10,091.
DE: 3947 Surfaces and interfaces
DE: 3994 Instruments and techniques
DE: 2164 Solar wind plasma
DE: 2169 Sources of the solar wind
DE: 2194 Instruments and techniques
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting