The performance of 300 kV multi-isotope low-energy AMS system (MILEA) for ¹⁴C, ¹²⁹I and Actinides

BackgroundAccelerator Mass Spectrometry (AMS) is a powerful technique for ultra-trace analysis of long-lived radionuclides whilst the performance is the mean concern for practical application.PurposeThis study aims to evaluate the performance of a 300 kV multi-isotope low-energy accelerator mass spectrometry (MILEA) system installed at the China Institute for Radiation Protection (CIRP) for measuring ¹⁴C, ¹²⁹I, and actinide nuclides.MethodsThe system was systematically tested through on-site acceptance and tuning measurements. Firstly, the transmission efficiency from the low-energy end to the high-energy end and current intensity were measured for stable isotopes. Then, the ratios of rare radionuclides to stable nuclides and abundance sensitivity were determined using blank samples. Finally, the measurement precision was evaluated by analyzing multiple standard samples.ResultsMeasurement results show that the ¹⁴C/ ¹²C blank ratio achieved is (1.3±0.1)×10 ⁻¹⁵. The ¹²⁹I/ ¹²⁷I blank ratio in Woodward iodine is (3.76±0.2)×10 ⁻¹⁴. For actinide measurements, the abundance sensitivity of ²³⁹Pu/ ²³⁸U is (1.5~2.7)×10 ⁻¹³, and the detection limits for Pu isotopes, ²³⁷Np, and ²⁴⁴Cm reached the 10 ⁻¹⁸ g level.ConclusionsEvaluation results of this study demonstrate that the CIRP-AMS system achieves excellent performance competitive with larger AMS facilities, making it suitable for ultra-sensitive analysis of ¹⁴C, ¹²⁹I, and actinide nuclides in various applications.