| 摘要 |
PURPOSE:To obtain a stable ion beam by making good use of an ionization metal contained in a crucible by separately heating and controlling the ionization metal and an emitter chip. CONSTITUTION:A crucible 6 has a conical bottom surface having in its central top an orifice which is packed with an ionization metal 4. An emitter chip 1 is installed penetrating the crucible 6 and the ionization metal 4. A ring-like heating filament 5 is installed surrounding the emitter chip 1. A heater 7 with a proper shape is installed around the crucible 6 in order to heat it. The heater 7 is heated with a power supply 8 which is installed independently of a power supply used to heat the heating filament 5. When the emitter chip 1 is heated to high temperature, the ionization metal 4 touching the emitter chip 1 is molten by conducted heat and the molten metal reaches the end of the emitter chip 1 after flowing over its surface. |
