  The present state of the art axion haloscope employs a cylindrical resonant
cavity in a solenoidal field. We, the Center for Axion and Precision Physics
Research (CAPP) of the Institute for Basic Science (IBS) in Korea, are also
pursuing halo axion discovery using this cylindrical geometry. However, the
presence of end caps of cavities increases challenges as we explore higher
frequency regions for the axion at above 2 GHz. To overcome these challenges we
exploit a toroidal design of cavity and magnetic field. A toroidal geometry
offers several advantages, two of which are a larger volume for a given space
and greatly reduced fringe fields which interfere with our preamps, in
particular the planned quantum-based devices. We introduce the concept of
toroidal axion haloscopes and present ongoing research activities and plans at
CAPP/IBS.
