PURPOSE: Show them what a large photomultiplier tube looks like.

DESCRIPTION: This is a large (8") photomultiplier tube which was once used in a particle physics experiment. The photocathode surface (on the inside front face of the tube), the focusing electrodes, and the dynodes are all easy to see.

The tube at the right is a small version of the type used in the Super Kamiokande project in Japan.

SUGGESTIONS: Do not drop it. Because it is heavy and made of glass, it is probably not a good idea to pass it around the class.

REFERENCES: (PIRA unknown.)

EQUIPMENT: Large phototube.

SETUP TIME: None.