This scattering angle, is the angle between the direction of the scattered beam and the direction of the incident beam. The idea of the experiment is straightforward: Monochromatic X-rays with wavelength are incident on a sample of graphite (the “target”), where they interact with atoms inside the sample they later emerge as scattered X-rays with wavelength A detector placed behind the target can measure the intensity of radiation scattered in any direction with respect to the direction of the incident X-ray beam. The schematics of Compton’s experimental setup are shown in (Figure). The explanation of the Compton effect gave a convincing argument to the physics community that electromagnetic waves can indeed behave like a stream of photons, which placed the concept of a photon on firm ground. The Compton effect has a very important place in the history of physics because it shows that electromagnetic radiation cannot be explained as a purely wave phenomenon. To explain the shift in wavelengths measured in the experiment, Compton used Einstein’s idea of light as a particle. Compton and his collaborators, and Compton gave its explanation in 1923. This classically unexplainable phenomenon was studied experimentally by Arthur H. Contrary to this prediction of classical physics, observations show that when X-rays are scattered off some materials, such as graphite, the scattered X-rays have different wavelengths from the wavelength of the incident X-rays. By classical theory, when an electromagnetic wave is scattered off atoms, the wavelength of the scattered radiation is expected to be the same as the wavelength of the incident radiation. The Compton effect is the term used for an unusual result observed when X-rays are scattered on some materials.

Light converse wave definition