Adjust incident photon energy and scattering angle to observe photon and electron interactions, and visualize the relationship between scattered photon energy and angle on a graph.
What is Compton Scattering?
Compton scattering is a phenomenon where X-rays or gamma rays (photons) collide with electrons in matter, losing energy and changing direction. In this process, the photon loses energy and its wavelength increases, while the electron gains energy and recoils. This is a crucial phenomenon that proves photons exhibit particle-like properties in addition to wave-like properties.
Importance of Compton Scattering
- Medical Field: It affects the quality of X-ray images and is an important consideration in radiation therapy planning.
- Radiation Protection: Essential for understanding how radiation interacts with matter to design effective shielding materials.
- Fundamental Physics: It provided crucial experimental evidence proving the particle nature of photons, contributing significantly to the development of quantum mechanics.
How to Use the Simulator
This simulator visually demonstrates the key elements of Compton scattering.
- Incident Photon Energy: This is the initial energy of the photon before it collides with an electron. You can adjust this value using the slider. Higher energy changes the proportion of energy lost by the photon after scattering.
- Scattering Angle (θ): This is the angle at which the incident photon changes direction after colliding with an electron. You can adjust it from 0 degrees (straight through) to 180 degrees (bouncing straight back).
Interpreting the Results
As you adjust the sliders, two main results are updated in real-time:
- Scattered Photon Energy (E′): This is the energy of the photon after it has lost energy in the collision. As the scattering angle increases, the photon transfers more energy to the electron, so the scattered photon's energy decreases.
- Recoil Electron Energy (Erecoil): This is the energy of the electron that gains energy and recoils after colliding with the photon. Its energy is equal to the incident photon energy minus the scattered photon energy.
The diagram visually shows the relative directions of the incident photon, scattered photon, and recoil electron. The graph below dynamically illustrates the change in scattered photon energy (E′) with respect to the scattering angle (θ) for a given incident photon energy, helping to clarify the physical relationships in Compton scattering.
Compton Scattering Formulas
The energy of the scattered photon ($E'$) is calculated using the following formula:
$E' = \frac{E}{1 + \frac{E}{m_e c^2}(1 - \cos\theta)}$
- E: Incident photon energy
- m_e c^2: Rest mass energy of the electron (approximately 0.511 MeV)
- θ: Scattering angle
The energy of the recoil electron ($E_{recoil}$) follows the law of conservation of energy and is given by:
$E_{recoil} = E - E'$