| 摘要 |
In this photomultiplier tube (1), light incident on a light-receiving faceplate (3) is converted into photoelectrons by a photosensitive surface (3a), and the photoelectrons strike a dynode (4) to emit many secondary electrons. The secondary electrons are then collected by a mesh-like anode (5). Since the anode (5) is disposed to be parallel to the photosensitive surface (3a), the photoelectrons emerging from the photosensitive surface (3a) can easily pass through a mesh portion (5a), and many photoelectrons can be made to strike the dynode (4). As the number of photoelectrons incident on the dynode (4) increases, the number of secondary electrons from the dynode (4) increases. This improves the gain characteristics of the photomultiplier tube (1). In addition, since the anode (5) is formed to have a flat shape conforming to the shape of the photosensitive surface (3a), the mesh-like anode (5) can be easily molded. Since a secondary electron emission surface (4a) of the dynode (4) is tilted with respect to the anode (5), photoelectrons having passed through the anode (5) obliquely strike the secondary electron emission surface (4a) of the dynode (4). As a consequence, the number of secondary electrons emitted can be increased. This also improves the gain characteristics of the photomultiplier tube (2). <IMAGE> |
