Physics

Electron

Shell (structure)

Born approximation

Electron shell

Atomic physics

Composite material

Nuclear physics

Chemistry

Materials science

Ionization

Range (aeronautics)

Electron ionization

Quantum mechanics

Cross section (physics)

Coulomb

Journal of Physics B Atomic Molecular and Optical Physics

Results from measurements of K-shell ionization cross sections of the elements Cr, Ni and Cu by electron impact with energies in the range 6.5-40 keV are presented. Cross sections were obtained by measuring characteristic x-rays emitted from (1-6 nm thick) films of the studied elements deposited on self-supporting carbon backing films. The procedure yields relative cross sections with uncertainties of the order of 2%. Transformation to absolute units increases the uncertainties to about 10%. Our results are compared with those from other groups and with two calculations based on the first Born approximation, which include corrections for exchange, Coulomb and relativistic effects. A simple empirical formula that accurately describes the energy dependence of the measured cross sections is provided.

Measurements of K-shell ionization cross sections of Cr, Ni and Cu by impact of 6.5-40 keV electrons