Elastic Electron Scattering Amplitudes for Neutral Atoms Calculated Using the Partial Wave Method at 10, 40, 70, and 100 kV for <i>Z</i> = 1 to <i>Z</i> = 54

Abstract

Elastic electron scattering amplitudes for neutral atoms were calculated using the partial wave expansion method for 10-, 40-, 70-, and 100-kV incident electrons. The partial wave phase shifts were calculated by numerical intergration using the phase amplitude method until the results converged to values obtained using the WKBJ and first Born approxmations, which were then used in the remainder of the partial wave sum. The static potential field of the target atoms was represented by an analytical expression involving a sum of Yukawa terms. Potential field parameters for the expression were obtained by a least-squares fit of the radial electron distribution function, D (r), using Hartree—Fock and relativistic wavefunctions for all the neutral atoms from Z=1 to Z=54. For the smaller atoms from Z=1 to Z=21, Clementi Hartree—Fock wavefunctions were used and for the atoms from Z=22 to 54 Liberman—Waber—Cromer D (r) curves calculated using the Dirac Hamiltonian incorporating a j—j coupling scheme and the Slater ⅔ approximation in the exchange potential were used.