Cross section of an atom for elastic scattering that is greater than the
Rutherford cross section due to partial penetration of a nucleus in the sample by the incident particle.
Source:
PAC, 2020, 92, 1781. 'Glossary of methods and terms used in surface chemical analysis (IUPAC Recommendations 2020)' on page 1833 (https://doi.org/10.1515/pac-2019-0404)