  This article presents the conceptual design of a new compact superconducting
gantry and synchrotron for Carbon ion therapy and focuses on the solutions
(layout and optics) to make it compact. The main specificity of this gantry
design is to be smaller and lighter with respect to the existing carbon-ion
gantries. This is achieved by adopting an innovative mechanical design and by
using superconducting magnets of the Canted Cosine Theta type with a small
aperture. The optics is optimized to reduce the beam size, it is achromatic and
it is independent of the rotation angle (for an incoming round beam). A
preliminary synchrotron layout based on similar superconducting magnets units
is presented and the dose delivery specificities are discussed.
