PURPOSE: Demonstrate the existence of cosmic rays.

DESCRIPTION: Two scintillator paddles with phototubes are used to detect cosmic ray muons. A coincidence unit is used to obtain cosmic ray coincidences between the two paddles when they are positioned along a vertical line. Set one detector on a chair and hold the second detector above it to see coincidences; move the upper paddle horizontally to demonstrate that the muons are coming straight down from the upper atmosphere. The bottom paddle can be placed on a chair, a student lies on that detector, and the second detector is held over the student to demonstrate that cosmic rays are passing through the student (or other victim).

SUGGESTIONS: This one is fairly complicated, so you must receive instruction before use.


EQUIPMENT: Roll-around relay rack with cosmic ray coincidence apparatus.

SETUP TIME: 30 min..

Go back to Lecture-Demonstration Home Page.