Here's why:
* J.J. Thomson's Experiment: Thomson's famous experiment involved using a CRT to study the properties of cathode rays. He showed that these rays were actually streams of negatively charged particles, which he named "electrons".
* How the CRT Worked: A CRT is a vacuum tube that uses an electron gun to generate a beam of electrons. This beam is then directed towards a fluorescent screen, causing it to glow.
* Thomson's Discoveries: By applying electric and magnetic fields to the electron beam, Thomson was able to measure the charge-to-mass ratio of the electron, proving its existence as a fundamental particle.
So, while the CRT itself isn't just a detector, it was the crucial tool Thomson used to both process and detect electrons, leading to his groundbreaking discovery.
