Electron Excited L X-Ray Spectra of the Elements 14 ≤ Z ≤ 22

The L spectra of the elements 14 ≤ Z ≤ 22 were reinvestigated. Because of the limited energy resolution of the multilayer reflectors neither Ll and Lη nor Lα and Lβ₁ could be resolved. Nevertheless, the line Lβ_3,4 = L₁M_2,3 was observed for all elements Z ≥ 16, but not for ¹⁴Si and ¹⁵P. Exceptions to this are ¹⁸Ar and ²²Ti. For ¹⁸Ar no suitable sample is available. In the case of ²²Ti the Lβ_3,4 line is overlapped by the O Kα line which has its origin in the oxide surface layer of the Ti standard. In all cases the Lβ_3,4 line was observed near to the expected position which was determined by means of the known electron binding energies. The L spectrum of ²¹Sc was studied for various energies of the incident electrons, E₀. These measurements show that Lβ_3,4 is much more strongly absorbed in Sc than Ll,η and Lα,β₁. From these measurements approximate mass absorption coefficients (m.a.c.) were deduced. The relative net peak height I(Lβ_3,4)/I(Lα,β₁) decreases from 15% at E₀ = 4 keV to 4% at E₀ = 20 keV, whereas I(Ll,η)/I(Lα,β₁) remains nearly constant at 90%. The peak to background ratio of Ll,η is greater than that of Lα,β₁.