摘要 |
With the outer wall surface (2b) of a metal-made side tube (2) of a photomultiplier (1) flush with the edge face (4b) of a stem plate (4), the side tube (2) is secured to the stem plate (4) by welding, and thereby there is no projection like a flange at the bottom of the photomultiplier (1), reducing the size of the photomultiplier (1). Therefore, though it is difficult to perform resistance welding, the outside dimensions of the photomultiplier (1) can be decreased, and multiple photomultipliers (1) can densely abut to one another in such a way that the side tubes (2) are put together even if the photomultipliers (2) are arranged when applied. Hence, high-density arrangement of photomultipliers (1) are realized by assembling metallic stem plate (4) and the side tube (2) by, for example, laser welding. <IMAGE> |