A key technique for the CHIME dating of Cenozoic samples: accurate dead time correction

Abstract

Accurate dead-time correction is an important technique in the CHIME dating using electron probe microanalyzer (EPMA) for the accurate determination of trace amounts of lead in Cenozoic and other samples. The uncertainty of the dead time varies from one monochromator to another, and also varies with the aging process. In order to eliminate systematic errors in the dead time correction, we have developed an electronic circuit that allows the blind time to be regarded as constant with acceptable uncertainty.