Design study of 20 t, 15 cm bore hybrid magnet with radiation resistant insertfor pion capture

摘要

To capture pions the Neutrino Factory and Muon Collider Collaboration needs afield of (approx)20 T throughout a cylinder 15 cm in diameter and 60 cm long, falling over the next 18 m to 1.25 T, while the bore increases fourfold inversely as the square root of the field. We propose a hybrid system. The superconducting magnet is of world-class parameters, storing 600 MJ and including a coil to generate 14 T in a bore of (approx)1.3 m. Intercoil forces reach 100 MN. For high radiation resistance, the insert coil is of mineral-insulated hollow conductor, as developed for the Japan Hadron Facility; it would require 12 MW to generate 6 T. Needed is research to develop a more efficient hollow conductor or radiation-resistant insulator for a Bitter coil.