註釋 In October 2005 the "Multiple Ion Counting" (MIC) system was installed as an additional detector system into the Triton TIMS instrument at IRMM. This detector system allows the simultaneous detection of up to seven small ion currents of 10-19 - 10-14 A in ion counting mode, corresponding to count rates of 1 - 60.000 cps (counts per second). In order to circumvent complicated inter-calibration routines for the given set of 7 ion counters the principle of multi-dynamic measurements was adapted for the "Multiple Ion Counting" (MIC) system. After the successful installation and performance of acceptance test measurements the new MIC system was used for verification measurements of the NUSIMEP 5 (Nuclear Signatures Measurement Evaluation Program) interlaboratory campaign samples, containing uranium at the pg level and plutonium at the pg level. The results show good agreement with the certified data and therefore confirm the reliability of the MIC system for low level actinide isotope ratio analyses 