We calculate its radialization correction and make the correlative discussion,obtain the cross section of electron-antielectron collision under chain approximation,and compare the tree-level cross section with the cross section under chain approximation.

L-shell ionization cross sections of Ag by electron impact in the energy range from 5 to 22 keV have been determined with a Si(Li) X-ray detector.

Especially in high-temperature plasmas-whether in laboratory (nuclear fusion) or in astrophysics (atmosphere of stars)-atoms become ionized into multiply-charged ions by electron impact.

The electron-impact ionization cross section for metastable state ion;