Re-designing a TSI FMAG 1520 for the production of monodisperse
uranium-oxide microparticles. A status report.

For the analysis of individual micrometer- and sub-micrometer-sized particles collected on swipe samples by International Atomic Energy Agency (IAEA) safeguards inspectors during in-field verification, well-defined microparticulate reference materials are requested by IAEA for quality control measures. In this context, an aerosol-based approach to produce U3O8 microparticulate reference materials is implemented in the laboratories of the Forschungszentrum Jülich. Since 2020 the Safeguards Laboratory at Forschungszentrum Jülich has been first and to date only qualified member of IAEA’s NetWork of Analytical Laboratories (NWAL) for the provision of microparticle reference materials for particle analysis in nuclear safeguards. The centrepiece for the production of these uranium oxide-based microparticles is a modified aerosol generator, TSI VOAG 3450 (Vibration Orifice Aerosol Generator), which was acquired in 2012. Unfavourably, TSI has ceased the production of the VOAG and will soon also cease servicing and procuring spare parts. Therefore, and because of the extension of the chemical composition of the microparticles to include more complex systems e.g., Pu doped uranium oxide, a new aerosol generator, the TSI FMAG 1520 (Flow Focussing Monodisperse Aerosol Generator), was purchased. In order to produce particles of comparable quality (like VOAG) and to build up on existing experience, the original setup of FMAG needs to be significantly modified. The redesign has to meet a number of requirements: (1) it has to fit into a glove box, (2) all steps of a particle production such as cleaning or replacement of parts has to be easily performed in a glove box environment. In addition, the redesign allows to bring in the experience made with the VOAG to enable a wider variation of the process. An overview of the status of the redesign of the TSI-FMAG and first results will be presented.