Crook_Tubes-variants

Wikipedia

"Crookes tubes evolved from the earlier Geissler tubes, experimental tubes which are similar to modern neon tube lights. Geissler tubes had only a low vacuum, around 10⁻³ atm (100 Pa),^[6] and the electrons in them could only travel a short distance before hitting a gas molecule. So the current of electrons moved in a slow diffusion process, constantly colliding with gas molecules, never gaining much energy. These tubes did not create beams of cathode rays, only a colorful glow discharge that filled the tube as the electrons struck the gas molecules and excited them, producing light."

See other pages for 1879: "Crookes put a tiny vaned turbine or paddlewheel in the path of the cathode rays, and found that it rotated when the rays hit it. The paddlewheel turned in a direction away from the cathode side of the tube, suggesting that the rays were coming from the cathode.

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