| 摘要 |
PROBLEM TO BE SOLVED: To enhance a mass resolving power by suppressing a kinetic energy width an ion pulse. SOLUTION: In this mass spectrometer, when ions are accumulated in an ion reservoir 3, an extruded plate 4 is set to the ground potential and an intermediate electrode 11 is applied with a minus voltage VW. Thereby, an ion beam flies in the y-direction holding approximately a converged condition in the ion reservoir 3. Consequently, the spatial spread of the ion in the z-direction in the ion reservoir 3 can be suppressed at minimum. It allows suppressing the kinetic energy spread of the ion when emitted as an ion pulse from the ion reservoir 3 and a mass resolving power can be enhanced. In addition, first and second mirror electrodes 12 and 13 are disposed on the inlet and outlet sides of the ion reservoir 3 and the optimal voltage is applied on the extrusion plate 4, a grid 5, the intermediate electrode 11 and the first and second mirror electrodes 12 and 13. Thereby, the ion beam can be reciprocated zigzag several times to accumulate. |
