The bundle divertor – part I: Magnetic configuration

This paper describes the main features of a device which has been called a Bundle Divertor. Its purpose is to improve the purity of a tokamak plasma by reducing the flux of plasma bombarding the walls, and also by reducing the influx of impurities from the walls into the plasma. The name derives from the bundle of magnetic field lines, localized in both major and minor azimuths, which is diverted out of the torus into a separate chamber. Although these diverted field lines do not form perfectly closed magnetic surfaces, it is shown, through analysis of extensive numerical field-line computations, that these effects should not impair the divertor action.