236U analyses with the ETH Zurich MILEA prototype system

Compact, low energy accelerator mass spectrometry (AMS) has evolved over the past years as one of the most sensitive, selective, and robust techniques for the analysis of heavy and long lived radionuclides. In this study, we focus on the analytical capabilities of the compact AMS system MILEA, mainly for 236U analyses. First, the setup of the system for actinide analyses is presented and the special technical setup for 23xU/238U (x = 3, 6, 5) is discussed. Then, the background and sensitivity for 236U/238U are studied in detail, and finally results from the first routine runs are presented and discussed. Our results show that the ETH Zurich MILEA system is ideally suited for fast, reliable, high sensitivity, and almost background free analyses of 236U/238U in environmental samples allowing the analysis of larger batches of samples with reasonably small sample sizes or volumes.

Automated summary

Compact, low-energy accelerator mass spectrometry (AMS) has become one of the most sensitive, selective, and robust techniques for analyzing heavy and long-lived radionuclides. This study focuses on the analytical capabilities of the compact AMS system MILEA, specifically for 236U analyses. The setup for actinide analyses and the technical setup for 23xU/238U (x = 3, 6, 5) are discussed, followed by a detailed investigation of the background and sensitivity for 236U/238U. The results demonstrate that the ETH Zurich MILEA system is well-suited for fast, reliable, high-sensitivity, and nearly background-free analyses of 236U/238U in environmental samples.