Ultra High Brightness Plasma Ion Source for SIMS Imaging of Actinides at the Theoretical Resolution Limit.

This proposal outlines a project aimed at providing a radical improvement in ion source technology that can be applied to the mass spectrometric analysis of actinides. The state-of-the-art secondary ion mass spectrometers (SIMS), used for actinide analysis, employ the duoplasmatron ion source for creating the primary ion beam. This ion source only has sufficient brightness and a small enough energy spread to create focused oxygen ion beams as small as 200nm in diameter, with a very low ion beam current of & lt;1pA. In order to analyze sub-micron actinide particles with sufficient speed, the current density needs to be increased by approximately an order of magnitude. Focused oxygen beam diameters as small as 10nm are required in order to provide the highest possible imaging resolution using the SIMS technique, but today this is far from possible. Furthermore the lifetime and reliability of the duoplasmatron can be very problematic, causing a significant amount of downtime for these very expensive instruments. Phase I and II of this project is targeting a dramatically enhanced ion source performance, that coupled with optimized beam focusing optics will provide oxygen ion beam diameters down to 10nm and xenon beam diameters of 7nm. The ion source will have no consumable electrodes and has the potential for uninterrupted operation for more than a year without any significant performance degradation. If successful, the beam current density will be more than a factor of 100 greater than that provided by the duoplasmatron and will increase analysis speed proportionately. Applications include rapid, high resolution SIMS and RIMS (resonant ion mass spectrometry) analysis of actinides. The primary objective here is to enhance the analysis equipment used by our nations nuclear forensic scientists in their efforts to prevent nuclear proliferation amongst rogue nations and terrorist organizations. If successful, this project will reduce SIMS analysis times from hours to seconds and improve the imaging resolution by over an order of magnitude.