New Design of the ECRIS Plasma Chamber Using a Modified Multipole Structure

It has been found that the radial magnetic field strength plays an important role for the production of highly charged ions with an Electron Cyclotron Resonance Ion Source. Remarkable improvement in the ion source performance has been achieved due to the upgrade of the permanent magnet hexapoles. Unfortunately, methods to increase the radial magnetic field strength are often limited. We have studied a new method, known as the Modified Multipole Structure (MMPS) in which the magnetic field is increased only at the locations where the plasma flux hits the plasma chamber wall. A MMPS plasma chamber for the JYFL 6.4 GHz ECRIS has been designed in order to experimentally study the new idea. This article presents the results of simulations, along with the design and features of MMPS plasma chamber.