Crookes tube

Crookes tube

A Crookes tube is a highly evacuated tube developed by Williams Crookes for the study of electrical discharges at low pressure. It was used in 1897 by J. J. Thomson to demonstrate the existence of the electron, and was also used to generate X-rays.


In the photographs shown here, the electrons travel in straight lines from the cathode on the left, shown by the shadow cast by the cross on the fluorescence on the right-hand wall. The anode is at the bottom.