Co-axial multicusp source for low axial energy spread ion beam production

A co-axial multicusp ion source has been designed and tested. This source u ses a new magnetic filter configuration. This magnetic filter is efficient in modifying the plasma potential distribution which can reduce the axial e nergy spread of the extracted ion beam. Energy spreads as low as 0.6 eV hav e been obtained. The electron temperature in this source has also been foun d to be about 0.1 eV. Furthermore, the new source configuration is capable of adjusting the radial plasma potential distribution which can improve the transverse ion energy, which results in a low beam emittance. The co-axial source can be used for a number of different applications such as ion proj ection lithography and radioactive ion beam projets. (C) 1999 Elsevier Scie nce B.V. All rights reserved.