In 1928, English physicists G.P. Thompson and A. Reid, working with high speed electrons, showed that when a narrow beam of high-speed electrons produced from heated tungsten filament was allowed to fall on the surface on of a thin metallic foil like Al Au, Pt etc. and the diffracted electrons are received on photographic plate kept in a short distance away, these electrons produce a different luminous spot composed of electronic bright and dark rings which are called electron beam diffraction rings or patterns.
These diffraction patterns are obtained due to the fact that metal consists of many microscopic crystals arranged in random fashion so that some are always at the proper angles to give reflection rings given by electron beam are found to be similar to those given by X-rays (which are waves) when they are diffracted by the same meta foil. This similarity between the electron beam diffraction rings and those of X-rays rings confirms that electrons are also waves.
These diffraction patterns are obtained due to the fact that metal consists of many microscopic crystals arranged in random fashion so that some are always at the proper angles to give reflection rings given by electron beam are found to be similar to those given by X-rays (which are waves) when they are diffracted by the same meta foil. This similarity between the electron beam diffraction rings and those of X-rays rings confirms that electrons are also waves.
(a) X-rays beam diffraction rings (b) Electron beam diffraction rings
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