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

Abstract

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.

Copper fine-structure K-shell electron impact ionization cross sections for fast-electron diagnostic in laser-solid experiments

“…cross section curves are summations over all the fine-structure transitions from the Cu 0 ground level. The measurements of Llovet et al [15] are systematically higher than our calculations although our curves cross their 10% error bars for most of their experimental values.…”

“…1, our calculated K-shell EII cross sections in Cu 0 are compared to the experimental data compiled by Liu et al [13], the measurements of Zhou et al [14] and of Llovet et al [15] and the fitted cross section of Davies et al [1]. Our DW + extrapol.…”

“…The resulting EII cross sections are expressed in barn using the following parametrized formula for each fine-structure transition [1]; full circles: compilation of experimental data by Liu et al [13]; open circles: measurements by Zhou et al [14]; open squares: measurements by Llovet et al [15]. …”

Measurements of absoluteK-shell ionization cross sections andL-shell x-ray production cross sections of Ge by electron impact

“…[16]. To obtain the x-ray production cross section X we measured the flux N X ͑E͒ of characteristic x rays emitted from an ultrathin film of thickness t of the studied element, bombarded with N e electrons of energy E. The x-ray production cross section is then obtained as…”

The investigations on K and L X-ray fluorescence parameters of gold compounds

“…K-shell X-ray production cross sections for proton, helium and lithium ions in In and Sn were measured by Yu et al (2005) using a HpGe X-ray detector with a resolution of 145 eV at 5.9 keV. The measurement of K-shell ionization cross-sections of Cr, Ni and Cu was performed by Llovet et al (2000) by impact of 6.5-40 keV electrons. Furthermore, the measurements of L shell photoionization cross-sections were carried out by many researchers (Yu et al, 1997;Hallak, 1998;Al-Saleh and Saleh, 1999;Mandal et al, 2001;Wu et al, 2007;Puri et al, 1996).…”