What was the name of the equipment John Thomson did?

The name of the equipment that John Thomson did the experiments was cathode ray tube.

Explanation:

John Thomson's experiments was to study the nature of electric discharges in a cathode ray tube. They are sealed glass tubes and the inside of the tube was maintained in high vacuum. John Thomson's cathode ray tube experiments were significant because he proved that all the atoms contain, electrons. Electrons are the negatively charged subatomic particles. Cathode ray is the particle beam that contains this negatively charged electrons.