| 摘要 |
PURPOSE:To increase an oscillation efficiency and to attain a microwave discharge of a large output by a method wherein a means such as a dielectric having holes opened or a metal mesh is provided in the outer periphery of a discharge tube, impression is given by using the means, thereby an electric field strength is made uniform and a uniform discharge is executed. CONSTITUTION:A dielectric 2 having holes opened is provided in the outer periphery of a discharge tube 12. Although an electric field strength is varied by providing the dielectric, a control of the distribution of the electric field strength is easier than in the case when a metal ridge is used. Besides, a more excellent effect is produced by executing the control of an electric field by means of the dielectric having the holes opened than by providing the dielectric simply and varying the thickness thereof. In another way, a metal mesh 3 is provided in the outer periphery of the discharge tube 12. Although a metal part of the metal mesh generates the same electric field as the ridge, the metal mesh has openings through which the electric field passes, and the electric field is put in a state wherein strong and weak fields are jumbled up. |
