| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative ion source device capable of increasing the generation amount of negative ions.SOLUTION: A negative ion source device 100 comprises a filter magnetic field generator 110B for generating magnetic field for blocking electrons having predetermined energy or more, and a promoting agent adhering face increasing part 117 which is provided in a magnetic field area (negative ion generation area E2) where magnetic field is generated, and increases the area of a portion to which promoting agent adheres. The electrons having the predetermined energy or more are intercepted from intruding into the magnetic field area based on the filter magnetic field generator 110B, so that negative ions can be generated in the magnetic field area while the magnetic field area is not broken by electrons having high energy. The work function is lowered by the promoting agent on the surface of a portion of the magnetic field area to which the promoting agent adheres, thereby performing negative ion surface generation. Accordingly, the promoting agent adhesion face increasing part 117 is provided in the magnetic field area, thereby increasing the area of the portion at which the negative ion surface generation is performed.SELECTED DRAWING: Figure 2 |
