Anode ray
（重定向自Anode rays）
![Anode ray tube showing the rays passing through the perforated cathode and causing the pink glow above it.](/Images/godic/202412/21/Anode_Ray_Tube2008.jpg")
![Simplified representation of an anode ray tube, showing the rays to the right of the perforated cathode](/Images/godic/202412/21/Anode_ray_tube_800X4002008.jpg")
An anode ray (also positive ray or canal ray) is a beam of positive ions that is created by certain types of gas discharge tubes. They were first observed in Crookes tubes during experiments by the German scientist Eugen Goldstein, in 1886. Later work on anode rays by Wilhelm Wien and J. J. Thomson led to the development of mass spectrometry.