| 摘要 |
PROBLEM TO BE SOLVED: To provide a photodetection unit capable of sufficiently suppressing incidence of noise light on a light incident part of a photomultiplier tube through a flexible wiring board.SOLUTION: A photodetection unit 100 includes: a photomultiplier tube 1 having a housing 5 which is constituted of a lower frame 4 having a photoelectric surface 41, an upper frame 2 facing the lower frame 4, and a sidewall frame 3 interposed between the lower frame 4 and the upper frame 2; an energizing part 112 on which the photomultiplier tube 1 is mounted and which is electrically connected to the photomultiplier tube 1; a flexible wiring board 120 whose one end 120x is connected to the energizing part 112; a light shielding case 111 which houses the photomultiplier tube 1, the energizing part 112, and the one end 120x of the flexible wiring board 120 and has a slit 111a corresponding to a light incident window 43; and a light shielding member 113A disposed between a noise light emitting part 120a of the flexible wiring board 120 and the light incident window 43 of the photomultiplier tube 1. |
