We have measured the Lα, Lβ, , , L , and Lη x-ray production cross sections of Au by 50–100 keV electron impact. From this experimental information we derived the L1, L2 and L3 subshell ionization cross sections with a novel analysis procedure that is based on an overdetermined system of equations and achieve the estimates by the least-squares method. The uncertainties in the atomic relaxation parameters needed to transform the x-ray intensities to ionization cross sections impose a lower limit to the relative standard deviations of the L subshell ionization cross sections, which is found to be 5–10% depending on the selected set of relaxation parameters. Our experimental results are in reasonable accord with most of the measurements carried out by other authors, and they agree with the predictions of the semi-relativistic distorted-wave Born approximation.

We have used the low-energy beam line of the São Paulo Microtron accelerator to study the maximum energy transfer point (tip) of electron-atom bremsstrahlung spectra for C, Al, Te, Ta and Au. Absolute cross sections differential in energy and angle of the emitted photon were measured for various electron kinetic energies between 20 and 100 keV, and photon emission angles of 35 • , 90 • and 131 • . The bremsstrahlung spectra were collected with three HPGe detectors and their response functions were evaluated analytically. Rutherford backscattering spectrometry allowed us to obtain the thicknesses of the targets with good accuracy. We propose a simple model for the tip region of the bremsstrahlung spectrum emitted at a given angle, whose adjustable parameters are the mean energy of the incident beam and its spread as well as an amplitude. The model was fitted simultaneously to the pulse-height distributions recorded at the three angles, determining the doubly differential cross sections from the corresponding amplitudes. The measured values have uncertainties between 3% and 13%. The agreement of the experimental results with the theoretical partial-wave calculations of Pratt and co-workers depends on the analyzed element and angle but is generally satisfactory. In the case of Al and Au, the uncertainty attributed to the theory is probably overestimated.

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We studied the full-energy peak efficiency of a Si drift detector (SDD) and a Si (Li) detector (SLD) using the formalisms proposed by Seltzer [Nucl. Instrum. Meth. 188 (1981) 133] and O'Meara and Campbell [X-Ray Spectrom. 33 (2004) 146]. The respective adjustable parameters were fitted to full-energy peak efficiencies measured with certified point radioactive sources. Seltzer's model was able to reproduce the experimental data for the SDD and the SLD in the 6-40 keV and 6-100 keV energy ranges, respectively. In turn, O'Meara and Campbell's formula also performed well for the SDD between 6 and 40 keV and proved to fit satisfactorily in the energy interval 6-60 keV for the SLD.

We measured the cross sections for Au Lα, Lβ, Lγ, Lℓand Lη x-ray production by the impact of electrons with energies from the L 3 threshold to 100keV using a thin Au film whose mass thickness was determined by Rutherford Backscattering Spectrometry. The x-ray spectra were acquired with a Si drift detector, which allowed to separate the components of the Lγ multiplet lines. The measured Lα, Lβ, L 1 g , L 2,3,6 g , L 4,4 g ¢ , L 5 g , ℓ L and Lη x-ray production cross sections were then employed to derive Au L 1 , L 2 and L 3 subshell ionization cross sections with relative uncertainties of 8%, 7% and 7%, respectively; these figures include the uncertainties in the atomic relaxation parameters. The correction for the increase in electron path length inside the Au film was estimated by means of Monte Carlo simulations. The experimental ionization cross sections are about 10% above the state-of-the-art distorted-wave calculations.