| 摘要 |
PURPOSE:To make sensitivity of detection constant irrespective of value of energy by forming a controlling means in which sensitivity of a detector is controlled properly in accordance with a field voltage value in an energy analysis means. CONSTITUTION:A controlling means is formed to control sensitivity of a detector properly in accordance with a field voltage value in an energy analyzer 5. Ions detected in a region, where the field voltage value in the energy analyzer 5 is small, are small in their energy, that is, low-speed, and so detected signal intensity is low. Thereupon, an applied voltage of a secondary electron multiplying tube 6 is controlled in a proper functional relation by CPU 7 so that the applied voltage of the tube 6 is more enlarged as the field voltage in the energy analyzer 5 becomes smaller. Sensitivity of the detected signal outputted from the secondary electron multiplying tube 6 can be hence made constant irrespective of the value of ion energy. |
