  Charged particle therapy, or so-called hadrontherapy, is developing very
rapidly. There is large pressure on the scientific community to deliver
dedicated accelerators, providing the best possible treatment modalities at the
lowest cost. In this context, the Italian research Foundation TERA is
developing fast-cycling accelerators, dubbed 'cyclinacs'. These are a
combination of a cyclotron (accelerating ions to a fixed initial energy)
followed by a high gradient linac boosting the ions energy up to the maximum
needed for medical therapy. The linac is powered by many independently
controlled klystrons to vary the beam energy from one pulse to the next. This
accelerator is best suited to treat moving organs with a 4D multi-painting spot
scanning technique. A dual proton/carbon ion cyclinac is here presented. It
consists of an Electron Beam Ion Source, a superconducting isochronous
cyclotron and a high-gradient linac. All these machines are pulsed at high
repetition rate (100-400 Hz). The source should deliver both C6+ and H2+ ions
in short pulses (1.5 {\mu}s flat-top) and with sufficient intensity (at least
108 fully stripped carbon ions at 300 Hz). The cyclotron accelerates the ions
to 120 MeV/u. It features a compact design (with superconducting coils) and a
low power consumption. The linac has a novel C-band high gradient structure and
accelerates the ions to variable energies up to 400 MeV/u. High RF frequencies
lead to power consumptions which are much lower than the ones of synchrotrons
for the same ion extraction energy. This work is part of a collaboration with
the CLIC group, which is working at CERN on high-gradient electron-positron
colliders.
