| 摘要 |
PURPOSE:To improve basic performance, such as sensitivity, resolution, and mass range, and the workability and productivity required for a GC direct coupling mass spectrometer by using a pole piece as the vacuum wall of a magnetic field analysis space and applying arbitrary voltage to the vacuum wall of the pole piece. CONSTITUTION:The vacuum walls 7 of a pole piece 2 are provided with insulating layers (for example, alumina coating and the like) 7a, respectively, and electric conductive layers 7b made of non-magnetic material are provided outside of the said insulating layers, respectively. For instance, the metallization of the said alumina layer and the like that use molybdenum powder is appropriate for the said conductive layers. The arbitrary voltage including ground potential can be applied to these conductive layers 7b from an electric induction terminal. As a result, arbitrary voltage can be applied to the vacuum surface of the said pole piece 2. An ion source can be grounded as a means that applies the ion acceleration voltage of a mass spectrometer and an analysis space can be set to high potential (negative for a positive ion and positive for a negative ion) centering around the said pole piece 2. |
