Terminology of quantum mechanics
When high-energy fast neutrons are injected into a substance and interact with the atomic nucleus (target nucleus) that makes up the substance, they are first absorbed by the target nucleus to form a composite nucleus, and then they emit lower energy neutrons. The target nucleus absorbs the energy and is in an excited state. This effect is called inelastic scattering.
- Chinese name
- Inelastic scattering
- Foreign name
- inelastic scattering
- Definition
- Internal structure of particles involved in scattering
- Applied discipline
- Terminology of quantum mechanics
- Category
- science and engineering
- Involved
- Conservation of energy
In the scattering process, if the internal energy and structure of the two particles involved in the scattering do not change, the scattering is called elastic scattering 。 In the process of elastic scattering, the system can obey conservation of energy and Law of conservation of momentum 。 On the contrary, as long as one particle participating in scattering changes its internal structure or energy (such as excitation), it is called inelastic scattering. [1] If the number, type and internal state of particles have changed or transformed into other particles in addition to kinetic energy exchange during collision, it is called inelastic scattering or Inelastic collision 。 In order to understand the reason for the difference between photons and neutrons, we will study the wavelength of Of neutrons, whose energy is Because under thermal equilibrium, the dominant thermal excitation has energy Therefore, from the inelastic scattering of solids, we can expect a considerable energy change. Moreover, after the reactor neutrons are moderated at room temperature, there will be many neutrons of this wavelength. On the other hand, for photons of the same wavelength, the energy is Therefore, in order to distinguish the energy change characteristics of solids, it will be necessary to compare The higher resolution can be obtained by X-ray. From what has been described above, we may think that neutrons are better than Ray. However, the neutron intensity used is relatively small, and the total thermal neutron flow obtained from the slow neutron reactor is only —— And it is drastically reduced due to the selection of narrow energy band. In fact, in neutron scattering experiments, collimation and Energy resolution 。 For this reason, it is better to use Ray. [2] 
