Atomic scattering factors for K-shell and L-shell ionization by fast electrons

Area of Science:

• Atomic Physics
• Materials Science
• Solid State Physics

Background:

• Accurate atomic scattering factors are crucial for quantitative microanalysis techniques.
• Existing data may lack precision or coverage for specific elemental ranges and scattering conditions.

Purpose of the Study:

• To calculate atomic scattering factors for K- and L-shell ionization for a wide range of elements.
• To provide parameterized data suitable for use in atom location by channelling-enhanced microanalysis (ALCHEMI).

Main Methods:

• Relativistic Hartree-Fock wave functions for bound states and Hartree-Slater wave functions for continuum states were employed.
• Calculations covered K-shell ionization (Z=6-50) and L-shell ionization (Z=20-60).
• Results were tabulated for interpolation and parameterized for different scattering vector ranges.

Main Results:

• Tabulated atomic scattering factors were generated for incident electron energies of 50-400 keV and scattering vectors up to 2.5 Å⁻¹.
• Separate parameterizations were developed for larger scattering vectors (2.5-20 Å⁻¹) and a simpler exponential form was fitted.
• The calculated factors are directly applicable to ionization cross-section calculations.

Conclusions:

• The computed atomic scattering factors provide essential data for advanced microanalysis techniques.
• The parameterizations enhance the utility of the data for various scattering conditions and applications like ALCHEMI.