| 摘要 |
PURPOSE:To prevent sticking of sample gas likely to freeze to the inner face of a plasma chamber by coaxially arranging an inner cylinder conductor thermally insulated through an electrical insulator in an outer cylinder conductor forming a plasma chamber. CONSTITUTION:Microwave power is propergated into a plasma chamber applied with a static magnetic field in the axial direction by a coil 4 through a central conductor 2 while ionizing a sample out of a heating furnace 10, which vaporizes phosphor or the like by heating, for taking out an ion beam 6 from said plasma of high density. Thereby, the plasma chamber 3 is so constructed as to house an inner cylinder 8 coaxially inside an outer cylinder 1 through an insulator 9 while thermally insulating the inner cylinder 8 from the outer cylinder 1. Accordingly, even when the outer cylinder 1 is water-cooled, sample gas likely to freeze is excluded from sticking to the inner wall face of the plasma chamber and the surface of the taking-out electrode 5 thus being able to take out an ion beam long and stably. |
