摘要 |
<p>A pair of coaxial electrodes 10 that face each other, a discharge-environment-maintaining device 20, and a voltage-applying device 30 are provided. Each coaxial electrode 10 includes a center electrode 12, a guide electrode 14 which surrounds the front end portion of the facing center electrode, and an insulation member 16 which insulates the center electrode and the guide electrode from each other. The insulation member 16 is formed of partially porous ceramics including an insulative dense portion 16a and a porous portion 16b. The insulative dense portion 16a includes a reservoir 18 which holds a plasma medium therein, and by the porous portion 16b, the inner surface of the reservoir 18 communicates with a gap between the center electrode 12 and the guide electrode 14 through the inside of the insulative dense portion 16a.</p> |