Toward a storage ring with no shear

One barrier to the attainment of a crystalline ordered state for a well-cooled beam in a storage ring will be the viscous heating by the shear induced in the bending fields of the ring. Shear will transfer some of the energy of coherent motion to thermal energy and may prevent reaching the very low temperatures required for formation of the ordered state. A concept for a ring is proposed in which shear within a monoenergetic beam of finite size is substantially reduced by means of combined electrostatic and magnetic fields within the bending elements.