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secondary emission




The emission of elementary particles by a target, such as a gas or metal surface, that is bombarded with primary (newly generated) radiation or particles. Secondary cosmic rays are emitted when primary cosmic rays bombard the atmosphere.

The anode of an electron tube emits secondary electrons when it is bombarded by primary electrons from the cathode. This principle is employed in electron-multiplying devices, such as an image intensifier.


Related category

   • ATOMIC AND NUCLEAR PHYSICS