The winding method and model of a superconducting bending dipole for hadrontherapy

The cancer therapy (hadrontherapy) with accelerated particle beams is an innovative method that allows an accurate and effective treatment of several kinds of tumors minimizing the irradiation of the surrounding tissues and avoiding intercepting vital organs. The deep tumors are usually treated with proton or ion beams by using a rotating gantry that allows the 360° irradiation of the patient. For the carbon ion hadrontherapy, being the energy in the order of 400 MeV, huge gantry structures are required if resistive magnets are used. An alternative solution was studied, involving the use of a cryogenic free superconducting magnet. The magnet consists of ten 90° bent superconducting dipoles wound with an aluminum stabilized Cu/NbTi conductor and mechanically supported by an aluminum alloy structure. In order to validate the feasibility of such a magnet, an accurate study of the winding technique was carried out, together with a winding test of a coil prototype.