A photomultiplier that prevents rattling between the dynodes and the base plates,
the parts being fixed securely to achieve excellent vibration resistance. The dynode
of the second stage (Dy2) includes a curved surface (Dy2A) having
an arcuate cross-section and a flat surface (Dy2B) formed continuously and
flush with the curved surface. The curved surface (Dy2A) and flat surface
(Dy2B) make up the secondary electron emitting surface. Side walls (Dy2C)
erected from the curved surface (Dy2A) are formed through a pressing process
on either lengthwise end of the curved surface (Dy2A). First ear portions
(Dy2D) extend outward from both side walls (Dy2C). Second ear portions
(Dy2E) extend outward from both lengthwise ends of the flat surface (Dy2B).
The first and second ear portions (Dy2D and Dy2E) are not parallel
to each other but form a fixed angle.
