| 摘要 |
PURPOSE:To enhance the signal-to-noise ratio of an output signal of the captioned tube as well as the X-ray transmissivity thereof and then the sensitivity of a pickuptube itself, by sticking a metal face-plate to the opening part of an insulator substrate having the opening part so that the opening part may be hermetically sealed. CONSTITUTION:The contact surface between a substrate 10 formed by boring an insulator plate made of glass, ceramics or the like and indium 4 is optically polished particularly at its periphery in order to be hermetically vacuum-sealed by sticking. On the other hand, the area of a Be face-plate 1 shall be the effective area required for operation of a pickup tube plus the area of its part bonded to the substrate 10, and also the thickness of the Be face-plate 1 shall be the thickness having such strength which can endure atmospheric pressure because said Be face-plate 1 includes a part of a vacuum enclosure 5. By doing this, the signal-to-noise ratio of the output signal can be greatly enhanced, the X-ray transmissivity and the sensitivity of the pickup tube itself can be also enhanced. |
