Design of a $\hbox {MgB}_{2}$ Beam Transport Channel for a Strong-Focusing Cyclotron

A superconducting strong-focusing cyclotron is being developed for high current applications. Alternating-gradient focusing is provided by ~ 6 T/m superconducting beam transport channels which lie in the sectors along the arced beam trajectory of each orbit of the cyclotron. The ~ 1 T sector dipoles, corrector dipoles, and Panofsky type quadrupoles utilize MgB₂ superconductor operating around 15-20 K. The operating temperature provides a valuable margin for a cost-effective cryogenic design, and large thermal stability in the event of occasional heat loads from intercepted beam or other sources. The main dipole windings are designed with sufficiently large curvature so that they can be fabricated using react-and-wind procedure; the quadrupole windings require small-radius end bends and so must be fabricated using wind-and-react procedure. Initial magnetic modeling on the end field region is presented.