| 摘要 |
PURPOSE:To obtain an analysis tube with high sensitivity and low background by installing a large aperture single lens between the cone-like magnetic field mass spectrograph and the ion source. CONSTITUTION:Gas molecules are ionized by electrons emitted by a filament 1 and accelerated toward an anode 2. Then, the thus produced ions are accelerated by an accelerating electrode 4 until they have a given energy before being made incident upon a single lens 13. Ions 15 passing through the single lens 13 are focused upon the steric convergence point of a cone-like magnetic field mass spectrograph 5 to form an apparent ion source for the magnetic field of the mass spectrograph 5, and then are introduced into the mass spectrograph 5. Since an ion source 3 is in a position free from the influence of the leakage magnetic field of the mass spectrograph 5 and an apparent ion source image is formed at the steric convergence point of the cone-like magnetic field of the mass spectrograph 5 by the single lens 13, the performance of the ion source 3 is not deteriorated. |
