| 摘要 |
PURPOSE:To prevent any change in the resistance of a secondary-electron multiplier consisting of an oxide semiconductor by installing it in a vacuum case and introducing gas of an oxidizing atmosphere into the vacuum case. CONSTITUTION:A secondary-electron multiplier consisting of an oxide semiconductor is installed in a vacuum case 1. A heater 3 discharges electron rays. A pipe 4, in which a switching valve 5 is installed, is connected to the case 1. An oxygen-gas storage chamber 6 is connected to the pipe 4 and heated by a heater 7. A heater 9 is attached around the case 1. The storage chamber 6 is used to accomodate an oxygen-discharging matter such as manganese oxide or titanium oxide. It is heated by the heater 7 to produce oxygen gas which is then introduced into the case 1 through the valve 5. Oxygen gas introduced into the case 1 is heated by the heater 9, thereby preventing any decrease in the resistance of the secondary-electron multiplier which might be caused by reduction and enabling matters adhering to the surface to be eliminated through an exhaustion hole or the like. |
