3P-16 PDF
Development of High-Gain Ion Detectors for Multiple Collector-ICP-Mass Spectrometer for High Resolution Chronology
The isotope chronometers, utilizing radioactive decay of U and Th, have been widely used for the age determination of the U-Th-bearing mineral such as zircon, monazite or apatite. Many geologists are increasingly interested in processes in rocks that operate under the lower temperatures or within the small minerals or area. To achieve this, coupling of laser sampling and the high sensitivity ICPMS system was employed. Hence, all the 202Hg, 204Pb, 206Pb, 207Pb, 208Pb and 238U signals were simultaneously monitored by means of multiple collector (MC) configurations equipped on the magnetic sector-based mass spectrometers. In this study, high-gain ion collectors utilizing a Daly detectors were adopted to the MC-ICPMS system. With the Daly detector, both the long-term stability and the higher signal output linearity, covering >7 orders of magnitude, could be achieved. In this presentation, we will discuss the basic performance of the multiple-Daly collector system for the isotope ratio measurements.