SPUTTER INITIATED RESONANCE IONIZATION SPECTROSCOPY FOR IN SITU MICROANALYSIS IN THE GEOSCIENCES

SPUTTER INITIATED RESONANCE IONIZATION SPECTROSCOPY (SIRIS),BASED ON THE CONCEPT OF RESONANCE IONIZATION OF SPUTTERED ATOMS, OFFERS THE POTENTIAL TO MAKE IN SITU CHEMICAL AND ISOTOPIC MICROANALYSES WITH EXCELLENT SENSITIVITY, MINIMAL FRACTIONATION AND MATRIX EFFECTS, AND FREEDOM FROM ISOBARIC INTERFERENCES-FACTORS WHICH FREQUENTLY LIMIT ION MICROPROBE ANALYSES IN GEOLOGICAL APPLICATIONS. MEASUREMENTS OF (1) CAAND TI ISOTOPE ANOMALIES IN HIBONITE, AND (2) EXCESS (40)CA IN POTASSIUM FELDSPAR ARE INTERESTING SCIENTIFIC PROBLEMS WHICH CHALLENGE THE PRESENT CAPABILITIES OF THE ION MICROPROBE. THE RESEARCHERS PROPOSE TO DEMONSTRATE THE POTENTIAL APPLICABILITY OF THE SIRIS TECHNIQUE FOR GEOLOGICAL STUDIES BY MEASURING THE CA AND TI ISOTOPE RATIOS IN THESE TWO MINERALS. PRELIMINARY RESEARCH WILL BE REQUIRED IN ORDER TO (1) ASSESS INTERFERENCE PROBLEMS DUE TO UNSUPPRESSED SECONDARY IONS AND NONRESONANT PHOTO-IONS AND EVALUATE METHODS FOR THEIR ELIMINATION; AND (2) EXPERIMENTALLY IDENTIFY AND EVALUATE RESONANT IONIZATION SCHEMES TO CA AND TI. RESULTS FROM THE PROPOSED RESEARCH WILL PROVIDE THE BASIS FOR THE DEVELOPMENT OF NEW ANALYTICAL METHODS WHICH WOULD SIGNIFICANTLY ADVANCE ANALYTICAL CAPABILITES IN THE EARTH SCIENCES AND PROMOTE NEW AREAS OF RESEARCH. THESE BENEFITS COULD EXTEND TO OTHER AREAS SUCH AS THE SEMICONDUCTOR INDUSTRY, THE BIOMEDICAL FIELD, AND ENVIRONMENTAL SCIENCES.