A 3-RATIO SCHEME FOR THE MEASUREMENT OF ISOTOPIC-RATIOS OF SILICON

This paper proposes a scheme of measurement sequences that has been us ed for the redetermination of the molar mass (atomic weight) of silico n at the Central Bureau for Nuclear Measurements (now Institute for Re ference Materials and Measurements). This scheme avoids correlations a mong the measured ratios caused by normalizing all ion current measure ments to that of the largest ion current. It also provides additional information for checking on the consistency of these ratios within a c ycle of scans. Measurements of isotope abundance ratios of silicon are used as an illustration.