| 摘要 |
PURPOSE:To enhance the positioning accuracy in the rotational direction of hyperbolic rods by causing the back section of each hyperbolic rod to form a cylindrical surface the center of which coincides with the center of an equivalent cylinder, and using a holder to support said rods in such a manner that the center position of the rod is accurately determined according to the cylindrical surface. CONSTITUTION:The section of electrode rods (R) forms a hyperbola in the area (A) which includes the facing surface of each electrode rod (R). The back surface of the electrode rod (R), (the entire circumference surface excluding the are a (A)), forms half of a cylindrical surface, the center (C) of which is located r0+r apart from the center (O) of a hyperbolic electric field. The symbol (r0) represents the distance between the center (O) and the apex of a hyperbola, and the symbol (r) represents the radius of the above described equivalent cylinder. A dotted line indicated in the figure represents an equivalent circle, and the radius (r') of the back section of the cylindrical surface of the electrode rod (R) is slightly larger than r. By forming a guide cut which has a circular cross section with radius (r') and the center of which is located accurately r0+r apart from the center (O), in a holder (H) before the electrode rod (R) is attached, the center position (C) of the electrode rod (R) is automatically and accurately determined. |
