Actinide measurements by accelerator mass spectrometry at Lawrence Livermore National Laboratory

Abstract

We report on the development of an accelerator mass spectrometry (AMS) system for the measurement of actinides at Lawrence Livermore National Laboratory. This AMS system is centered on a recently completed heavy isotope beam line that was designed particularly for high sensitivity, robust, high-throughput measurements of actinide concentrations and isotopic ratios. A fast isotope switching capability has been incorporated in the system, allowing flexibility in isotope selection and for the quasi-continuous normalization to a reference isotope spike. Initially, our utilization of the heavy isotope system has concentrated on the measurement of Pu isotopes. Under current operating conditions, background levels equivalent to ~1 X 10 5 atoms are observed during routine 239 Pu and 240 Pu measurements. Measurements of samples containing

Individual Radiation Protection Monitoring in the Marshall Islands: Rongelap Atoll (2002-2004)

“…Moreover, alpha spectrometry lacks the necessary detection sensitivity to accurately assess systemic plutonium uptake and dose in the Marshall Islands . (Brown et al, 2004;Hamilton et al, 2006). The technique has vastly improved the quality and reliability of assessments of urinary excretion of plutonium by Marshall Islanders and avoids many of the disadvantages of using conventional atom counting techniques or other competing new technologies.…”

Accelerator Mass Spectrometric (AMS) Measurements of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios In Soil Extracts Supplied by the Carlsbad Environmental Monitoring & Research Center

“…Figure1 Figure 1. Heavy isotope accelerator mass spectrometry system at LLNL (Brown et al, 2004) Negative plutonium ions (e.g., [239][240][241][242][243][244] Pu 16 O -) are produced from sample targets using a cesium splutter source and injected into the accelerator through a 90° electrostatic analyzer. Negative ions entering the accelerator are stripped, converted to positive ions and accelerated into the high-energy spectrometer of the AMS system.…”

Accelerator mass spectrometry

“…AMS has demonstrated improved detection limits for all these isotopes. For example, for plutonium isotopes the reported sensitivity of AMS is $10 6 atoms per sample during routine 239,240,241,242,244 Pu measurements (Brown et al, 2004). This can be compared with the daily urinary excretion of Pu for one person (in the general population) which is also $10 6 atoms.…”