Anode ray

  Anode rays (or Canal rays) were observed in experiments by a German scientist, Eugen Goldstein, in 1886. Goldstein used a gas discharge tube which had a perforated cathode. A "ray" is produced in the holes (canals) in the cathode and travels in a direction opposite to the "cathode rays," which are streams of electrons. Goldstein called these positive rays "Kanalstrahlen" - canal rays because it looks like they are passing through a canal. In 1907 a study of how this "ray" was deflected in a magnetic field, revealed that the particles making up the ray were not all the same mass. The lightest, formed when there was a little hydrogen in the tube, was calculated to be 1837 times as massive as an electron.

See also

• J. J. Thomson
• Wilhelm Wien
• Mass spectrometry