Compton Effect - Compton Scattering - Derivation of Compton Shift

This video is about Compton effect aka Compton Scattering and the derivation of Compton shift. Compton effect is the process by which electromagnetic radiation, generally either an x-ray photon or a gamma ray photon gets scattered by an electron whereby the photon loses some of its energy and hence emerges out as a photon of longer wavelength. So, the Compton effect is essentially a scattering process much like the scattering of billiard balls and hence also goes by the name Compton scattering. After the definition of the Compton effect, the video goes on to discuss different processes that involve interaction between light and electron such as the photoelectric effect. the pair production and pair annihilation and of course the Compton effect. A comparison of these processes is done and it is explained how these processes at different energy ranges of the interacting photons and the electrons. Then the term 'scattering' is introduced and different examples of light scattering are provided in the context of the Compton scattering. Then, the need for quantum mechanics to explain the Compton effect is emphasized while mentioning the ability of classical electromagnetic theory to explain the unscattered radiation is mentioned and how this leads to observation of unscattered radiation of the same wavelength as the original wavelength in Compton scattering is discussed. This forms the low energy limit of the Compton scattering. Then a detailed discussion of the derivation of the Compton Shift is done while explaining all the important concepts and strategies required for the derivation. The expression for Compton shift is discussed followed by an explanation of the Compton wavelength of the electron. The dependence of the Compton shift on the scattering angle of the photon is discussed. Compton's original experiment is discussed towards the end of the video and the results of this experiment are explained with relevant plots. The Compton shift is shown using these plots between the scattered x-ray intensity and x-ray wavelengths and how this wavelength is arrived at using the scanning angles of the Bragg spectrometer in the Compton experiment. It is also mentioned that the Compton effect was originally first observed by J.A. Gray which Compton wanted to experimentally verify. After verification, Compton went on to provide a theoretical explanation of the Compton effect using the photon theory of light for which he was awarded the 1927 Nobel prize in Physics. The video comes to a conclusion by stressing on the importance of Compton effect in the context of the development of Quantum Mechanics and how this experiment provided an important proof for the photon theory of light after the photoelectric effect.