Micro Ion Source Program NA22 Plutonium Detection Portfolio Final Report

Abstract

The purpose of the micro ion source program was to enhance the performance of thermal ionization mass spectrometry (TIMS) for various actinides and fission products. The proposal hypothesized that when ions are created at the ion optic center of the mass spectrometer, ion transmission is significantly increased and the resulting ion beam is more sharply focused. Computer modeling demonstrated this logic. In order to prove this hypothesis it was first necessary to understand the chemistry and physics governing the particular ion production process that concentrates the emission of ions into a small area. This has been achieved for uranium and technetium, as was shown in the original proposal and the improvement of both the beam transmission and sharpness of focus were proven. Significantly improved analytical methods have been developed for these two elements based upon this research. The iodine portion of the proposal turned out to be impractical due to volatility of iodine and its compounds. We knew this was a possibility prior to research and we proceeded anyway but did not succeed. Plutonium is a potential option, but is not quite up to the performance level of resin beads. Now, we more clearly understand the chemical and physical issues for plutonium, but have not yet translated this knowledge into improved analytical processes. The problems are that plutonium is considerably more difficult to convert to the required intermediate species, plutonium carbide, and the chemical method we developed that works with uranium functions only moderately well with plutonium. We are of the opinion that, with this knowledge, similar progress can be made with plutonium.