| 摘要 |
PURPOSE:To prevent an ion source, a slit and the like from being contaminated, by synchronizing the impression/cutoff of a primary ion acceleration voltage and the control of the movement of a target with each other to avoid irradiating an ion beam upon an unnecessary portion between samples. CONSTITUTION:A target 1, which includes samples spread on a thin chromatographic plate, is disposed on a holder 2, which is slid by a moving mechanism 3. Primary ions from an ion source are irradiated so that secondary ions are introduced into a magnetic field 5 for mass analysis. The impression and cutoff of a primary ion acceleration voltage for the ion source 4 are controlled synchronously with the movement of the positions A, B, C, D of the measured samples on the target 1. The beam of the primary ions is kept from being irradiated upon an unnecessary portion between the samples. The ion source and a slit are thus prevented from being contaminated by the ionization of the unnecessary portion. This results in enabling stable measurement for a long period of time. |
