Above-threshold ionization (ATI) is a multi-photon effect in which an atom is ionized by absorbing more than the minimum number of photons energetically required for ionization.
Notes on verification
Multiple independent peer-reviewed and scholarly sources (ScienceDirect, OSTI, Springer, arXiv) consistently corroborate the definition of above-threshold ionization as absorption of more photons than the minimum required for ionization.
Sources
- Above-threshold ionization (en.wikipedia.org)
- https://www.sciencedirect.com/science/article/abs/pii/0370157391901315 (sciencedirect.com)
- https://www.osti.gov/servlets/purl/1598264 (osti.gov)
- https://link.springer.com/chapter/10.1007/978-3-642-57208-1_7 (link.springer.com)
- https://arxiv.org/pdf/2505.14390 (arxiv.org)
- https://www.sciencedirect.com/science/article/abs/pii/S0375960116321521 (sciencedirect.com)
- https://arxiv.org/pdf/2012.12837 (arxiv.org)