Absolute electron impactK-ionization cross sections of titanium and nickel (?50 keV)

Abstract

Abstract. The absolute K-ionization cross sections of Ti and Ni by electron impact (impact energy__< 50 keV) was measured detecting the X-rays emitted by thin solid film targets of known mass thickness with a flow proportional counter. The experimental method, especially the correction procedures and the measurements are described, the results compared with calculations in different theoretical approaches. For impact energies above Eo/EK>I.5 (EK=K-shell ionization energy) a systematic deviation of about +20%occurs in comparison with the best agreeing calculations of M.R.H. Rudge and S.B. Schwartz. A fit to Drawin's empirical formula reveals that the measurements are approximated better than _+ 10 % within the range of comparison.

Experimental determination of cross sections forK-shell ionization by electron impact for C, O, Al, Si, and Ti

“…The experimental data sets were taken from Hink and Paschke [22] for carbon, Tawara et al [21] for carbon and oxygen, Glupe and Mehlhorn [20] for oxygen, Hink and Ziegler [15] for aluminum, Platten et al [17] for silicon and oxygen, Shchagin et al [16] for silicon, Jessenberger and Hink [18], and He et al [19] for titanium. These results can be found in the compilation of the experimental data performed by Liu et al [12], up to December, 1999.…”

“…Thickness and density of the films were characterized by x-ray reflectivity (XRR). The results were compared with experimental data from other authors [11,[15][16][17][18][19][20][21][22] and with theoretical and semiempirical curves available in the literature [4,9,10,[23][24][25][26][27][28].…”

Plane wave born cross sections including exchange forK-shell ionization of light atoms

“…As in the case of hydrogen, the PWBA cross sections agree well with experiment for Eo/I> 10, whereas the BornOchkur approximation agrees well with experi- [31], and. Jessenberger and Hiuk [32] ment also at the cross section maximum. For not too heavy Z elements, the present Born-Ochkur calculation thus agrees well with experiment from about twice the threshold energy up to incident electron energies where a relativistic treatment of the interaction becomes necessary.…”

Empirical model for the electron impact K‐shell ionization cross section of atoms

“…The experimental data are taken from Shah et al 19 for H; Rejoub et al 20, Schram et al 21, Shah et al 22, and Nagy et al 23 for He; Tawara et al 24 for C, N, Ne, and Ar; Egerton 25 and Isaacson et al 26 and for C; Gulpe and Mehlhorn 27 for N and Ne; Platten et al 28 for Ne, Si, and Ar; McDonald and Spicer 29 for Al; Hoffmann et al 30 for Al, Si, Ar, Cr, Ni, Cu, Y, Mn, Ag, Sn, Au, Pb, and Bi; Hink and Ziegler 31 for Al; Kamiya et al 32 for Al; Ishii et al 33 for Al, Si, Zn, Se, Y, Mo, Pd, In, Sn, Ba, Au, Pb, Bi, and U; Quarles and Semaan 34 for Ar; Scholz et al 35 for V, Cr, Co, Ni, Cu, Zn, Se, Rb, Sr, In, Sn, Ba, Au, Pb, and Bi; An et al 36 for V and Co; Luo et al 37 for Cr and Mo; He et al 38 for Cr; Jessenberger and Hink 39, and Pockman et al 40 for Ni; Genz et al 41 for Ni, Cu, and Ag; Seif el Naser et al 42 for Ni, Y, Ta and Pb; Middleman et al 43 for Cu, Sr, Mo, In, Ta, Au, and Bi; Berenyi et al 44 for Cu and Se; Hubner et al 45, Shima et al 46, and Shima 47 for Cu; Tang et al 48 for Zn; Zhou et al 49 for Ga; Kiss et al 50 for Se and Ag; Shevelko et al 51 for Sb and Sr; He et al 52 for Mo; Berkner et al 53 for Pd and Au; Ricz et al 54 for Pd, Ag, In, and Sn; Rester and Dance 55 for Ag, Sn, and Au; Schlenk et al 56 for Ag; and Davis et al 57 for Ag and Au. The optimum values of the parameters in the DMEMP model are A = 2.00, B 1 = B 2 = 0.50, D K = 5.2, λ = 0.16, m = 1.6, n = 1.1, and β = 0.4.…”