| 摘要 |
PURPOSE:To enable the deflecting plate of an electronic-ray apparatus to be cleaned without breaking up the system, by subjecting the deflecting plate to plasma etching. CONSTITUTION:A switch S1 is switched from a deflection power-source 9 to a high- pressure power-source 16, before a switch S2 is switched on to close an electromagnetic valve 2. Following that, in order to introduce gas form a bomb 19, a switch 3 is switched on to open an electromagnetic valve 20. As a result, the partial pressure of the gas in the system is raised, and discharge is initiated between a pair of deflection plates. Furthermore, the deflection plates reach plasma condition, and the surface of the plates are subjected to etching, thus the dirt of the surfaces being scattered. The dirt is exhausted outside the system by using vacuum exhaust equipment. |
