High performance AMS measurements of 129I at MILEA

Measurements of 129 I at the compact low-energy Accelerator Mass Spectrometry (AMS) system MILEA have been systematically studied to evaluate its performance. The system achieves high transmission (>50 %) through the accelerator, excellent background suppression of neighboring masses and molecular breakup products and significantly reduced cross-talk in the ion source by decreasing the Cs sputter energy to 2 keV. These improvements enable the detection of very low-level samples (Woodward Iodine) down to 1 × 10 −14 and the measurement of standard close to their nominal ratio (>90 %) with high precision. Furthermore, the implications of a recently revised, more precise half-life value of 129 I on our reference standards are discussed.