Sputter initiated resonance ionization spectroscopy for in situ microanalysis in the geosciences. Final report, 1 January-30 September 1989

Technical Report · Tue Jan 09 04:00:00 EST 1990

OSTI ID:5717410

Willis, R D; Thonnard, N

Sputter Initiated Resonance Ionization Spectroscopy (SIRIS) is a laser-based technique which has potential analytical advantages including high sensitivity and elemental selectivity. The objective of the research was to demonstrate the feasibility of the SIRIS technique for in situ analysis of geological samples. The research effort comprised the following tasks: (1) a SIRIS instrument was upgraded for application to geological specimens; (2) resonance ionization schemes for Ca and Ti were experimentally evaluated with respect to sensitivity and selectivity; (3) background from nonresonant photoions and unsuppressed secondary ions was assessed; (4) accuracy, precision, and sensitivity of a SIRIS system using a magnetic sector mass analyzer were evaluated for two demonstration cases: measurement of Ca and Ti isotope ratios in terrestrial hibonite, and measurement of Ca ratios in potassium feldspar; and (5) improvements to the SIRIS instrument were recommended and suggestions made for follow-on research. The 50Ti/48Ti ratio in hibonite was measured to better than 1% with a precision of 5%. The selectivity of the RIS process and the ability to suppress secondary ions were generally more than adequate. The accuracy and precision of the Ca measurements in hibonite and K-feldspar were limited by counting statistics and detector gain calibration uncertainty.

• Research Organization: Atom Sciences, Inc., Oak Ridge, TN (United States)
• OSTI ID: 5717410
• Report Number(s): PB-94-105558/XAB; CNN: NSF-ISI88-60854
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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CALCIUM ISOTOPES
CALIBRATION
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CHEMISTRY
FEASIBILITY STUDIES
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