Measurement of K-shell ionization cross sections of Fe and Mn by electron impact

Abstract

Measurements of K-shell ionization cross sections of Fe and Mn targets by the impact of electrons of 6-25 keV energy have been carried out. In the experiments thin targets with thick aluminium foil substrates were used. The influence on the measurements of electrons reflected from the aluminium substrate has been evaluated and corrected by a detailed electron transport calculation. It is shown that the corrected K-shell ionization cross sections of Mn are in good agreement with existing experimental data. For Mn and Fe, the corrected measured cross sections of K-shell ionization have been compared with the results of the empirical formula given by Casnati et al.

Measurements of absolute cross sections for K-shell ionization of Fe and Mn by electron impact

“…Figure 4 displays our experimental results, the analytical formula of Casnati et al (1982), and numerical calculations of Mayol and Salvat (1990), Hippler (1990) and Segui et al (2002), as well as experimental data from other authors. For Fe (figure 4(a)), our results are in relatively good agreement with those of Luo et al (1997); the results of He et al (1996) are about 30% larger. Here our data lie between the calculations of Segui et al (2002) and the Mayol-Salvat model, although a slightly better agreement is found with the former calculation.…”

“…Here our data lie between the calculations of Segui et al (2002) and the Mayol-Salvat model, although a slightly better agreement is found with the former calculation. In the case of Mn (figure 4(b)), our results (solid circles) are in relatively good agreement with Hippler's theoretical model, while those of Shima (1980), Luo et al (1997) and Tang et al (1999) seem to agree more closely with the Mayol-Salvat model. Although somewhat obscured by the absolute uncertainties of our data, the agreement with the results from the DWBA calculations of Segui et al (2002) and Casnati et al (1982) is considered satisfactory.…”

An empirical expression for K-shell ionization cross section by electron impact

“…Values of the Handbook of Chemistry and Physics (Boca Raton, FL: Chemical Rubber Company) are used for Kshell ionization energies. Excellent agreement is obtained between values deduced from the expression proposed and cross sections measured precisely by Shima [30,31] and Luo et al [32][33][34][35][36] in the vinicity of the threshold. The accuracy is better than 10% in this range.…”

“…U 4) [29]. Recent measurements of the K-shell ionization by electron impact near-threshold energy region have been performed [32][33][34][35][36]. These near threshold measured cross sections are in excellent agreement with the previous data which were precisely measured [30,31].…”

Generalized binary-encounter-Bethe model for electron impact ionization of atoms

“…Figures 1(a)-(c) compare the present K-shell (1s 1/2 ) EII cross section of the C, Al, and Fe atoms, respectively, with existing measurements by Tavara et al [30], Hink and Ziegler [31], Limandri et al [32], Ishii et al [33], Hoffmann et al [34], Kamiya et al [35], McDonald and Spicer [36], Scholz et al [37], He et al [38], Luo et al [39] and Llovet et al [40]. We also compare the present results with other empirical models such as the RBEB by Kim et al [17], the MUIBED by Patoary et al [26], and the DWBA results by Bote et al [6].…”