K-shell ionization cross sections of K and L_α X-ray production cross sections of I by 10–30 keV electron impact

Abstract

The absolute K-shell ionization cross sections of K and Lα X-ray production cross sections of I by 10–30 keV electron impact have been measured. The target was prepared by evaporating a thin film of compound KI to a thick pure carbon substrate. The effects of multiple scattering of electrons penetrating the target films, electrons reflected from the thick pure carbon substrates and bremsstrahlung photons produced when incident electrons impacted on the targets were corrected by using the Monte Carlo method. For K K-shell and I L-shell X-ray characteristic peaks, the spectra were fitted using the spectrum-fitting program ALLFIT to extract the Kα and Kβ peak counts more accurately for element K, and Lα peak counts for element I. The experimental results were compared with some theoretical results developed recently and available experimental data from the literature. The experimental data for I L-shell X-ray production cross sections by 10–30 keV electron impact are given here for the first time.

Cross sections of K-shell ionization by electron impact, measured from threshold to 100 keV, for Au and Bi

“…Liu and co-workers tabulated the experimental information available prior to year 2000 on measured K-shell ionization cross sections [1]. More measurements on atomic K shells have been carried out since then by the research group of Sichuan University [2][3][4][5][6][7][8][9][10][11][12][13], the collaboration between the Universities of Montpellier and Barcelona [14][15][16][17], as well as other authors [18][19][20]. Unfortunately, the results of [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] extend, at most, up to around 40 or 45 keV because the employed electron guns cannot be operated at higher energies.…”

“…More measurements on atomic K shells have been carried out since then by the research group of Sichuan University [2][3][4][5][6][7][8][9][10][11][12][13], the collaboration between the Universities of Montpellier and Barcelona [14][15][16][17], as well as other authors [18][19][20]. Unfortunately, the results of [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] extend, at most, up to around 40 or 45 keV because the employed electron guns cannot be operated at higher energies. Hence, the methodologies set up in the aforementioned publications are constrained to measure K-shell ionization cross sections of atoms with atomic number ≲ Z 60 (or x-ray production cross sections of L and higher shells).…”

Measurements of K-shell ionization cross sections of Al and L-shell x-ray production cross sections of Se by intermediate-energy electron impact

“…A thin Al film on thick carbon substrate target was also used to compare the results with a self-supporting monoatomic and grid carbon target. In addition, for the L-shell ionization cross-sections or x-ray production cross-sections of lower-and medium-Z elements, the measurements are relatively scarce and significant differences exist between the theoretical models and the experimental data from different authors [1,25,26,[29][30][31]. Furthermore, to the best of our knowledge, there are no experimental data for Se L-shell published till now.…”

M αβ X-ray production cross sections of Pb and Bi by 9–40 keV electron impact

“…However, experimental data of atomic inner-shell ionization cross sections impacted by low-energy electrons are still scarce. [11][12][13] For the reported experimental data of K-and L-shell ionization cross sections by electron impact in the incident electron energy region up to several keV, it seems that the DWBA theory is more suitable than the other recently developed theoretical models for the description of atomic ionization. [13][14][15][16][17][18] Up to now, there are very few studies for M shells.…”