부산대학교 도서관

This paper describes the front end design for the RIA driver linac which is able to select, separate and accelerate in the RFQ the required ion species of one- or two-charge states. The front end consists of an ECR ion source located on a 100 kV platform, LEBT, RFQ and MEBT. The first section of the LEBT is an achromatic bending system for charge-to-mass analysis and selection. For the heaviest ions with masses above 180, the transport system is able to deliver to the entrance of the first buncher a two-charge-state beam with similar Twiss parameters for both charge states. In order to match two-charge-state ions with different mass to charge ratios, the straight section of the LEBT upstream of the RFQ will be placed on a high-voltage platform. A voltage /spl sim/30 kV is required in order to match velocities of ions with mass to charge ratio less than the design value and to maintain the possibility accelerating two charge states simultaneously. Several beam matching schemes in the transitions LEBT-RFQ and RFQ-MEBT have been studied.