recoil electron

physics

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July 13, 2026

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A recoil electron is an electron that gains energy and momentum after being struck by a photon or another charged particle. This interaction is a key process in how radiation, such as gamma rays and X-rays, interacts with matter.123

In Compton scattering, a photon collides with an electron, transferring some of its energy to the electron and changing the photon's direction. The energy transferred to the electron depends on the scattering angle. This energetic electron is then called a recoil electron.13

Delta rays are atomic electrons that have gained enough energy from a passing charged particle to ionize other atoms along their path. These energetic electrons are also a form of recoil particle.2

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radiation measurement
Compton scattering
…it scattered, producing an energetic recoil electron. The fraction of the photon energy that is transferred depends on the scattering angle. When the incoming photon is deflected only slightly, little energy is transferred to the electron. Maximum energy transfer occurs when the incoming photon is backscattered from the electron and…
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…it scattered, producing an energetic recoil electron. The fraction of the photon energy that is transferred depends on the scattering angle. When the incoming photon is deflected only slightly, little energy is transferred to the electron. Maximum energy transfer occurs when the incoming photon is backscattered from the electron and…
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X-ray
Particle nature
…momentum to an electron, which recoils. The scattered photon must thus have less energy and momentum than the incoming photon, resulting in scattered X-rays of slightly lower frequency and longer wavelength. Compton’s careful measurements of this small effect, coupled with his successful theoretical treatment (independently derived by the Dutch scientist…
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…momentum to an electron, which recoils. The scattered photon must thus have less energy and momentum than the incoming photon, resulting in scattered X-rays of slightly lower frequency and longer wavelength. Compton’s careful measurements of this small effect, coupled with his successful theoretical treatment (independently derived by the Dutch scientist…
Read More