Au L α and L β and Ag L-shell x-ray production cross-sections by electron impact have been measured in the incident energy region from near threshold to about 25 keV. Thin films with thick aluminium substrates were used as targets in the experiments. The effect of directional and energy spreading of the electron beam within the active films and x-ray enhancement due to backscattering electrons and bremsstrahlung photons from the substrates are corrected by means of Monte Carlo simulations. The corrected experimental data provided by this method are compared with calculated cross-sections from a PWBA theory with Coulomb, relativistic and exchange corrections and with other experimental data available in the literature.

The measurement of Lα, Lβ x-ray production cross sections for the element Pb (Z = 82) by 16–40 keV electron impact is reported in this paper. The target used in the experiment was prepared by evaporating the elemental Pb onto a thick pure carbon substrate. The effects of multiple scattering of electrons when penetrating the target film, of electrons reflected from the thick pure carbon substrate and of bremsstrahlung photons produced by the impact of incident electrons on the target are corrected using the Monte Carlo method. The experimental data, reported here for the first time in the energy region of interest, are compared with the plane-wave Born approximation theory with exchange, Coulomb and relativistic corrections. They are in good agreement.

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Lα, Lβ x-ray production cross-sections for Gd (Z = 64) and W (Z = 74) by electron impact up to 40 keV have been measured. Thin films with thick carbon substrates were used as targets in the experiments. The effects of multiple scattering of electrons when penetrating the target film, of electrons reflected from the thick pure carbon substrate and of bremsstrahlung photons produced by the impact of incident electrons on the target were corrected by means of Monte Carlo simulation. For Gd L-shell x-ray characteristic peaks, the spectra were fitted by using spectrum-fitting program ALLFIT to extract more accurately the Lα and Lβ peak counts. The experimental data are compared with the DWBA theory and the PWBA–C–Ex theory and available experimental data from the literature.

A soft x-ray pulse height analysis (PHA) system, based on a silicon drift detector (SDD), has been successfully implemented on EAST to measure spectra of soft x-ray emission. Utilizing the soft x-ray PHA diagnostic, the behavior of intrinsic and injected medium-Z impurities is first investigated on EAST and the preliminary observations are presented. There are hardly any K α emission peaks of metallic impurities including Ti (Z = 22), Cr (Z = 24), Fe (Z = 26), Ni (Z = 28) and Cu (Z = 29) in the soft x-ray spectra for an ohmic heating plasma due to lower electron temperatures, while remarkable peaks can be seen in a lower hybrid wave (LHW) heated plasma. The profiles of K α intensities of these metallic elements have been obtained with about 7 cm spatial resolution. It is observed that the K α emissions come mainly from the core plasma column of ρ 0.3 and found that their intensities are roughly proportional to the power of the LHW launched into the plasma. The Ar K α peaks can also be monitored when argon gas is puffed into the plasma. It is qualitatively confirmed that the K α lines of argon emitted from the lower ionic states are predominantly located in the outer plasma region, whereas the K α lines with higher energies are mainly from high ionization stages in the central region.

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.

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