Refractory Oxides with Tunable Porosity and Geometry as Versatile Fast-Release Solid Catchers for Rare Isotopes

Short-lived isotopes are expected to play a key role in unraveling the mysteries of nuclear physics, nuclear astrophysics, and fundamental interactions at low energies. With collaborators from the Department of Energy (DOE) laboratories, InnoSense, LLC (ISL) will develop high- temperature-capable solid catcher materials for use in the pre-Facility for Rare Isotope Beams (FRIB) to improve yields of rare isotopes as atomic or single-species molecular vapors. ISL will develop refractory yttria-stabilized zirconia (YSZ) porous monoliths as catchers, which retain open porosity after extended vacuum heating at high temperatures. The goal is to ensure that the YSZ disks retain open paths for effusion of atoms or molecules from the catcher to the ion source to harvest unused rare isotope beams. Simulations will be used as a predictive tool for the non-equilibrium processes for the transient species of interest. Phase I demonstrated the feasibility of fabricating porous YSZ disks (2-3 mm) retaining open, interconnected porosity on the meso- to macro-scale upon heating to 1600 C for up to 24 hours. These disks remain mechanically robust to handling and extended heating. In Phase II, we will refine the YSZ formulations to increase porosity and minimize sintering during vacuum heating at 15002000 C. Phase II will also be geared to scaling up prescreened YSZ disks off-line and conducting in-beam evaluations of release times during long-term heating (24168 hours). Modeling refractory compounds to optimize the selective release of specific elements as molecular sidebands is planned. Molecular species (oxides of carbon) are targeted in these measurements. Trace additives will be optimized to enhance selective release of important elements as molecular sidebands. Project team will compare the experimental release studies with the simulations. Engineering efforts to complement product commercialization activities for the DOE entry and spin-off markets will also be undertaken. Commercial Applications and Other Benefits: The immediate market need for these hot catcher materials is the DOE and installations like FRIB that have powerful and unique techniques for rare isotope production. Other commercial markets are electrodes in ultracapacitors and electrolytes in solid oxide fuel cells.