PERMANENT MAGNET TYPE ECR ION SOURCE

摘要

PROBLEM TO BE SOLVED: To provide a small practical ECR ion source capable of saving power and of being simplified. SOLUTION: This permanent magnet type ECR ion source 10 is equipped with: a plasma chamber 12; permanent magnets 16 mounted around the plasma chamber 12; and a high-frequency power source 18 for supplying high-frequency power; and is so structured as to generate multivalent ions by accelerating electrons in a mirror magnetic field generated in the plasma chamber 12 by the permanent magnets 16 by using the high-frequency power supplied from the power source 18 to sequentially tear off electrons from neutral atoms or ions. The ion source is so structured as to reduce intensity of a reverse magnetic field generated against an ECR magnetic field by forming a cut-out part 16a having a predetermined shape on a side surface of each permanent magnet 16. In this case, a structure composed by inserting a high-magnetic-permeability material 15 in each cut-out part 16a is further effective for restraining the reverse magnetic field. COPYRIGHT: (C)2005,JPO&NCIPI