Particulate capture of plutonium by high gradient magnetic separation withadvanced matrices

A high performance superconducting magnetic separator is being developed fo r near single particle retrieval from low concentration field collected sam ples. Results show that maximum separation is obtained when the effective m atrix element diameter approaches the diameter of the particles to be captu red. Experimentally, we were able to capture very dilute levels of 0.2 to 0 .8 mum PuO2 particles with dodecane as a carrier fluid. The development of new matrix materials is being pursued through the deposition of nickel dend rites on an existing stainless steel matrix material. The new materials are promising for the submicron collection of paramagnetic particles. Results indicate that these new matrices contain a high number of capture sites for the paramagnetic particles. We have also derived a force-balance model tha t uses empirically determined capture cross section values. The model can b e used to optimize the capture cross section and thus increase the capture efficiency. This enables the prediction of high gradient magnetic separator performance for a variety of materials and applications.