| 摘要 |
PROBLEM TO BE SOLVED: To perform continuous efficient ionization while heightening rigidity against a force from inside and suppressing deformation, by providing a tip surface with a curved surface to be recessed most at its approximate center so as to be bulged to the inside of a nozzle and boring a gas injection opening. SOLUTION: An end face plate 16 is sandwiched between the circumferential surface of the end of a nozzle main body 11 and a fixing nut 15 via a flat circular gasket 14. The end face plate 16 is formed of, for example, metal such as nickel and is provided with a spherical surface with a required curvature in a shape bulged to the inside of the nozzle body 11. A gas injection opening 13 of predetermined diameter is bored at the approximate center, i.e., the most recessed part of the end face plate 16. Upstream gas pressure is relatively extremely higher than downstream gas pressure with respect to both sides of the tip surface of the nozzle, and a large force is exerted on the tip surface from the inside of the nozzle. In spite of this, as the tip surface is bulged to the inside of the nozzle, the tip face has a larger strength against a force from the inside than in the case with a flat tip surface and is scarcely deformed. |
