| 摘要 |
PURPOSE:To obtain a compact device with high resolution and sensitivity by making both the angle of revolution phie of an electric field used in divergence and that phim of a convergent magnetic field have a relationship of phim 2phie. CONSTITUTION:The ion beam 2 emitted from the ion source 1 at an angle of divergence alpha is incident on the covergence electric field 5 with focal point F consisting of the conical electrodes 3 and 4 and the ion beam emitted from the electric field 5 is incident on the convergence magnetic field 6 with an inlet which is arranged in parallel with and near the outlet of the electric field 5. The collector slit I is provided at the real image point 8 of the magnetic field 6. In this case, the angle of revolution phie for the magnetic field and that of revolution phim for the magnetic field 6 satisfy the relationship of phim 2phie and phie is set to 20-30 deg.. This enables horizontal distance L between the source slit 5 and the compact slit I to be reduced and the ion beam axis of an orbit to become almost linear. This enables also the directional convergence and energy convergence conditions to be satisfied and a device with high resolution and sensitivity to be obtained. |
