Displacement damage

Damage initiated when energetic particles transfer enough momentum to displace lattice atoms. A recoil can generate a displacement cascade, while many displaced atoms recombine during the ensuing relaxation.

Removal of an atom from its original lattice site. Whether it leaves a surviving defect depends on subsequent collisions, recombination and relaxation.

Annihilation of a vacancy and an interstitial, or related relaxation of irradiation defects. The surviving damage after a cascade can be much smaller than its initial number of atomic displacements.

atomic displacements produced by collision-driven momentum transfer. It differs from the much larger electronic energy deposition that a fast alpha particle can produce along its track.

The minimum recoil energy required, for a specified atom and direction or a stated averaging convention, to produce a surviving displacement defect. It depends on material, direction and the defect-survival criterion.

A dimensionless estimate of displacement events per target atom under a specified damage model. It does not count the vacancies still present after recombination and microstructural evolution.

The rate of accumulation of displacements per atom. Equal final displacement dose reached at different rates can produce different defect populations because diffusion and recovery continue in elapsed time.

A sequence of atomic recoils and local relaxation following an energetic impact in a solid. It can leave isolated Frenkel pairs, clusters and regions of altered local structure, rather than one permanent defect per initial collision.

A lattice atom given a recoil by an incident particle. Its subsequent collisions can generate a displacement cascade; its energy distribution depends on the incident radiation and material.