OPERATIONAL EXPERIENCE WITH THE 450 KV INJECTOR FOR THE SUPERCONDUCTING CYCLOTRON

In order to get a correct bunching of the tandem beams to be injected into the K-800 superconducting cyclotron at LNS and to improve further the transmission inside the tandem, the construction of a new injecto r providing 450 keV negative ions became necessary. The project, funde d in 1990, is now complete. The commissioning of the 450 kV injector h as been carried our paying particular attention to some technical prob lems: 1) the presence of two different sources, which permits to switc h easily fi-um one source ru the other, has required to double all the hardware, except for the analyzing magnet and far the gas box. in ord er to be effective in reducing downtimes for maintenance: 2) the reduc tion of the electrical noise, which disturbs the computer control syst em; 3) the management of 79 analogic parameters and 110 digital parame ters, which has been performed in an environment where the classical c ontrol system via insulated bari fails because of the high potential g radient (10 kV/in), one of the highest ever obtained in conditioned ai r environment fur injectors. The main features of the 450 kV injector will be summarized. The main derails of the commissioning with the pla tform performances will be presented and some details of ion optics wi ll be given.