AbstractIn a spherical tokamak, power handling at the divertor region becomes more difficult than that of conventional tokamaks because of the narrow space at the divertor region. Here a new poloidal-bundle divertor is proposed for a spherical tokamak reactor. The bundle divertor is located at the bottom and/or top region of the torus, in addition to several poloidal guide coils. These coils are installed inside of the toroidal coil, because the copper conductor is adaptable in spherical tokamak devices. The magnetic field line outside the separatrix is guided to the lower region of the torus by the poloidal guide coils, and extracted outside of the torus through the adjacent toroidal coils by the bundle divertor coils. The bundle divertor configuration does not affect the shape of the core plasma as much, and the magnetic field ripple, due to these bundle coils, is negligible.