Establishment of Chemical Preparation Methods and Development of an Automated Reduction System for AMS Sample Preparation at Kigam

Abstract

ABSTRACT. Many previous studies on the sample preparation of various kinds of radiocarbon dating samples by accelerator mass spectrometry (AMS) have been examined at KIGAM (Korea Institute of Geoscience and Mineral Resources) and our own procedures have been established. Furthermore, an automated reduction system has been developed. The volume of the reduction region was minimized to improve the reduction yield, and air-actuated pneumatic valves and solenoid arrays were used for computer control of the system. Operation of all the valves and vacuum pumps and signals from the temperature sensors and pressure gauges were interfaced to a personal computer with an A/D board. A computer program was also developed to perform automatic operation of the reduction system. This system consistently shows a higher reduction yield than 90%. The reduction time of the system is currently 140 min.

Factors controlling typhoons and storm rain on the Korean Peninsula during the Little Ice Age

“…Samples were combusted in an elemental analyzer and generated CO 2 gas was purified cryogenically in a high-vacuum automatic preparation system (Hong et al 2010a) and converted to graphite by reduction on Fe powder with hydrogen gas in a quartz tube. We corrected for carbon isotope fractionation using δ 13 C values measured at the AMS facility (Hong et al 2010b). The 14 C ages were converted to calendar dates using IntCal13, Marine13 (Reimer et al 2013), and CALIB 7.0 (Stuiver and Braziunas 1993) (Table 1; Fig.…”

Calibration curve from AD 1250 to AD 1650 by measurements of tree-rings grown on the Korean peninsula

“…The EA was directly coupled with a 24-fold automatic reduction system [10], which was used to graphitize the samples with Fe catalyst and hydrogen gas at 600°C. The average graphite yield was around 93% after a 3-hour reduction process, and the graphite sizes were around 1 mg.…”

Radiocarbon measurement with 1 MV AMS at charge state 1+

“…After the chemical treatment, all samples, including the NIST Oxalic II and IAEA standard materials, were converted to CO 2 gas by combustion using an elemental analyzer (EA). Then the CO 2 gas was transferred to an automated reduction system [2], and reduced to graphite with H 2 and Fe catalyst at 640°C. All graphite samples were pelletized to be measured using AMS.…”