Ma. Bolorizadeh et al., MULTIPLE IONIZATION OF COPPER BY ELECTRON-IMPACT, Journal of physics. B, Atomic molecular and optical physics, 27(1), 1994, pp. 175-183
A pulsed crossed beam technique previously developed in this laborator
y has been used to study the electron impact ionization of copper. Pre
vious measurements have been very limited in scope and exhibit large d
iscrepancies. Relative cross sections sigma(n) for the formation of 1
to 5 times ionized copper have been measured with high accuracy within
the range 7.8-2100 eV. Individual cross sections have been obtained b
y normalization to absolute values of sigma(2) obtained by Freund et a
l at energies below 200 eV using a fast crossed beam technique. Weak s
tructures in sigma(1) can be attributed to Auger decay processes follo
wing the creation of 3s subshell and L shell vacancies but there is a
lack of other pronounced structures in sigma(n) for n>1 where many clo
se-lying subshell vacancies are involved. At 2100 eV cross sections as
are less than three orders of magnitude smaller than sigma(1).