Design study of main dipole magnet using permanent magnet for ILC damping ring

In the Technical Design Report (TDR) of International Linear Collider (ILC), electromagnets are assumed for the dipole magnets in the damping ring. However, the costs such as the electricity for coil excitations and cooling water pumps have to be paid, and accidents such as power supply breakdowns and water leaks would be anticipated. When we use permanent magnets instead of electromagnets, reductions of the operation and maintenance costs are expected together with less system failures. This paper reports the results of 3D magnetic field simulation of main dipole magnet with ferrite permanent magnets. (author)