The contribution of the INFN-LNS to the development of electron cyclotron resonance ion sources (invited)

The study of the axial injector for the superconducting cyclotron of the Laboratori Nazionali del Sud (LNS) began in 1989, with the aim of replacing the radial injection from a 15 MV Tandem with the injection by a modern electron cyclotron resonance ion source (ECRIS) which could be able to produce beams of highly charged ions to the same extent. The design of a superconducting ECRIS, named SERSE, was established in the two following years and funded since 1993, 2 yr before the extraction of the first beam from the cyclotron; the construction took more than 4 yr and in August 1997 SERSE, was ready in the test bench of CEA/DRFMC in Grenoble. The source was moved to LNS in May 1998 and since then it is operating with excellent results. During 1993-95, the concept of High B mode, on which SERSE was based, was tested at MSU-NSCL and the results have been applied to other sources, including the room temperature CAESAR that will share with SERSE the duty of the production of ions for the cyclotron. Even though the performances of this source are not comparable to the ones of SERSE, CAESAR is able to perfectly fulfill the ordinary request of our accelerator complex. The last project of LNS concerns the design of a scaled version of SERSE with higher field, to be operated at the gyrotron frequency (28 GHz or higher). The results of the existing sources will be reviewed, along with the main features of the new project. (C) 2000 American Institute of Physics. [S0034-6748(00)50702-3].