Abstract
A technique for realizing in situ isotope-ratio is reported for measuring small isotopic ratio by the use of the ion-microprobe. In the case of inhomogeneous insulator-samples, such as the primitive meteorites, the difference in conductivity of each grain causes considerable amount of instrumental mass discrimination. As a preliminary step to solve this problem, a metal channel is embedded and the analysis is taken along it. The method is effective to homogenize the surface ionization condition, and the 26Mg/24Mg ratio of individual spot with the size of 40 microns was measured with the error of less than ±3‰. This is a step to realize 2-dimensional isotopic ratio imaging.
