Real-time studies of irradiation effects at Argonne's HVEM-Tandem Facility

The HVEM-Tandem Facility consists of a 1.2 MeV high-voltage electron microscope and two ion accelerators, a 2 MV tandem accelerator and a 0.65 MV implanter. This unique combination of instruments allows in situ ion and/or electron irradiation experiments to be performed with simultaneous imaging and electron diffraction analysis at temperatures between 10 and 1200 K. Since its inception in 1981 as a DOE User Facility, Facility users have made important contributions in irradiation-effects such as solid state amorphization and crystallization, ion beam mixing, defect structures, radiation-induced segregation, secondary displacement phenomena, ion implantation, and the mechanical instability of advanced nuclear fuels under ion irradiation. The HVEM was manufactured in 1970-71 and reflects original HVEM technology of the 1960's. The analytical capabilities of the instrument are very limited by contemporary electron microscopy standards. In this paper an augmented facility including a new, state-of-the art HVEM, known as MicroLab, is being proposed which vastly increases the capabilities for performing in situ irradiation effects research by virtue of improved spatial resolution for various structural, microstructural and elemental microanalytical techniques; increased maximum electron energy; and capability for physical property determinations in real time