Status report on AMS measurements of plutonium isotopes using the 1MV Tandetron Accelerator at IFIN-HH

Abstract

Accelerator Mass Spectrometry is the most sensitive measurement method that allows us to determine 239, 240, and 244Pu radioisotopes in environmental samples with extremely low isotopic concentrations. By measuring plutonium isotopes, we focus our research activity on two main directions, monitoring of environmental nuclear pollution and nuclear astrophysics.This report gives an overview of the progress that was made in the determination of plutonium isotopes at IFIN-HH, and it starts with the studies performed for the transport and measurement of actinides using the 1MV Tandetron Accelerator. The 238U and 232Th isotopes were used as pilot beams for the determination of ion transport parameters, after which the isotopic ratios 239Pu/242Pu, 240Pu/242Pu, and 244Pu/242Pu were measured using the new Plutonium Standard ColPuS. The results obtained for the isotopic ratios agree with the consensus values of the standard. In addition, we developed radiochemical procedures for thorium, plutonium, and uranium separation, the chemical recoveries of uranium and thorium using UTEVA and TEVA resins are presented, where we used an Agilent ICP-MS system (Inductively Coupled Plasma Mass Spectrometry). The radiochemical separation is important mainly for obtaining target materials that can provide microscopic pilot beams as U and/or Th. Finally, a short overview is provided of the molecular interference challenges that are encountered when measuring plutonium isotopes.