| 摘要 |
PURPOSE:To improve the electron collecting efficiency by making the braking electric field enter inside of through holes of a dynode sufficiently. CONSTITUTION:In an electron tube provided with an electron multiplier for multiplying the incident electron flow by discharging the secondary electron, a dynode 10a forming an electron multiplier is formed by arranging multiple through holes 12, of which one end is formed into an input opening 13 and the other end thereof is formed into an output opening 14, in a plate 11, and a diameter of the output opening 14 of each through hole 12 is formed larger than that of the input opening 13 thereof. An equal potential line A is thereby formed so as to enter from each output opening 14 having a large diameter and rise along the inside surface 16 opposite to an inclination part 15 and enter inside of each through hole 12 deeply. |
