Comparison of the measurement of Pu and Am isotopes by AMS using fluoride and oxide anion beams

Pu-239,Pu-240 and Am-241 isotopes can be measured by Accelerator Mass Spectrometry (AMS) using iron oxide and neodymium fluoride matrices. This report summarizes the measurements of Pu-239,Pu-240 and Am-241 in oxide and fluoride matrices by isotope dilution using the same accelerator system and sample preparation techniques at A. E. Lalonde AMS Laboratory (AELL), University of Ottawa. The advantages of each method of Pu and Am isotope measurement are assessed by studying the sensitivity, detection limits, and precision of both techniques. Based the ease of sample preparation, efficiency of ionization, and sensitivity, the fluoride method has an edge. The separation of Pu-239,Pu-240 and Am-241 from the sample matrix using a single extraction chromatography column prepared with DGA resin, and their measurements by AMS in fluoride matrices, was tested using the low level certified reference material (IAEA-414). The measured concentrations of Pu-239,Pu-240 and Am-241 agreed with the concentrations in the standard reference material.