| 摘要 |
PURPOSE:To generate a stable ion beam, by operating a heater for liquid metal heating use with constant-voltage drive at the initial stage of current supply and afterward operating it with constant-current drive, while impressing voltage for ion generating use at a point of time when the temperature comes to the steady value. CONSTITUTION:A temperature sensor 30 is installed in a reservoir 2 of an ion gun comprising the reservoir 2 having an enclosed liquid metal and an emitte 1, a heater 3, a drawing out electrode 6 and a cathode 7, and thereby the output signal is inputted into both a device 31 controlling a heater power supply E2 and a device 32 controlling drawing out power supplies E1 and E3 used for ion generation. Then, with the device 31, the heater 3 is operated with constant-voltage drive at the initial stage of current supply and, in turn, operated with constant-current drive at a point proximate to the desired value of temperature, while both the acceleration power supply E1 and the drawing out power supply E3 are made by the device 32 after the temperature reaches the steady value. Therefore, even when heat capacity of the reservoir 2 is large enough, an ion beam can be steadily generated in a short time. |
