TY - GEN
T1 - A laser desorption resonance ionization mass spectrometer for Rb-Sr geochronology
T2 - 2012 IEEE Aerospace Conference
AU - Anderson, F. Scott
AU - Mahoney, John
AU - Waite, Hunter
AU - Nowicki, Keith
AU - Young, David
AU - Norman, Marc
AU - Taylor, Jeff
AU - Whitaker, Tom
AU - Miller, Greg
AU - Boyce, Joe
PY - 2012
Y1 - 2012
N2 - We are developing a portable laser desorption resonance ionization mass spectrometer (LDRIMS) for determining the radiometric age of rocks using the 87Rb- 87Sr isotope system, as well as constraining lithologic evolution and measuring chemical compositions. The bench-top prototype has been used to assess the capability of LDRIMS to measure 87Sr/ 86Sr. In this paper, we demonstrate that LDRIMS can measure the isotope ratios of a glass standard with 10 ppm net Sr to a precision of ±0.5% (1σ), with a sensitivity of 1:10 10 in less than 1 minute. Increasing the measurement time to 15 minutes improves the precision to 0.1% (1σ). The speed of the LDRIMS measurement allows samples to be measured in significantly shorter periods of time than traditional methods, with little or no sample preparation. Models of the age error derived from isochron dating the SNC meteorites that would be obtained using 100-1000 LDRIMS measurements at ±0.1% (1σ) accuracy show that for ALH84001 and Zagami, which have ages ranging from 4.09 Ga to 165 Ma, dates with analytical uncertainties less than ±50 Ma are possible. These results were obtained using low laser powers (∼10 μJ for resonance, <1 mJ for photoionization), consistent with the potential for space flight to Mars.
AB - We are developing a portable laser desorption resonance ionization mass spectrometer (LDRIMS) for determining the radiometric age of rocks using the 87Rb- 87Sr isotope system, as well as constraining lithologic evolution and measuring chemical compositions. The bench-top prototype has been used to assess the capability of LDRIMS to measure 87Sr/ 86Sr. In this paper, we demonstrate that LDRIMS can measure the isotope ratios of a glass standard with 10 ppm net Sr to a precision of ±0.5% (1σ), with a sensitivity of 1:10 10 in less than 1 minute. Increasing the measurement time to 15 minutes improves the precision to 0.1% (1σ). The speed of the LDRIMS measurement allows samples to be measured in significantly shorter periods of time than traditional methods, with little or no sample preparation. Models of the age error derived from isochron dating the SNC meteorites that would be obtained using 100-1000 LDRIMS measurements at ±0.1% (1σ) accuracy show that for ALH84001 and Zagami, which have ages ranging from 4.09 Ga to 165 Ma, dates with analytical uncertainties less than ±50 Ma are possible. These results were obtained using low laser powers (∼10 μJ for resonance, <1 mJ for photoionization), consistent with the potential for space flight to Mars.
UR - http://www.scopus.com/inward/record.url?scp=84861162163&partnerID=8YFLogxK
U2 - 10.1109/AERO.2012.6187061
DO - 10.1109/AERO.2012.6187061
M3 - Conference contribution
SN - 9781457705564
T3 - IEEE Aerospace Conference Proceedings
BT - 2012 IEEE Aerospace Conference
Y2 - 3 March 2012 through 10 March 2012
ER -