| 摘要 |
PURPOSE:To prevent the corrosion of a pin-like electrode and enable a stable glow discharge to be performed by planting the pin-like electrode into the recess of an insulating substrate or a metallic member provided therein so that a large electric field is not generated in the neighborhood of the root of the pin- like electrode. CONSTITUTION:A recess 25 is provided in an insulating substrate 23 made of ceramics and a pin-like electrode 13 is planted thereon. The distal end of the pin-like electrode 13 is rolled in an approximately circular shape in order to remove sharp portions and the rear end of the pin-like electrode 13 penetrates the insulating substrate 23, being connected to a power supply line 5 via a ballast capacitor. The recess 25 of the insulating substrate 23 has a the diameter of the degree that the tail of a negative glow 27 does not touch the periphery of the recess 25 and the depth l of the degree that the tail of the negative glow 27 does not reach the bottom of the recess 25. Thus, a stable glow discharge can be conducted without the corrosion of the neighborhood of the root of the pin-like electrode 13. Further, it is more effective that a metallic flanged annular member 31 is fit in the recess 29. |
