Cathode Ray Tube - Shadow Effect - Maltese Cross

Purpose

Demonstrate the shadow effect for electrons.

Equipment

Cathode ray tube and power supply.◙

Images

p3-21

Description

A conical shaped tube has a cathode at the small end and an anode near the center; a Maltese cross is attached to the anode. The inside surface of the large end fluoresces when electrons strike it, revealing the shadow of the cross, and showing the origin of the rays to be the cathode.

References

Lecture Demonstrations, Bill Norwood, Radiation Safety Check of the Maltese Cross (Jan 1985).