Extraction of momentum expectation values from Compton profiles

Abstract

A linear combination of hydrogenic lorentzian functions is proposed as a model for fitting isotropic Compton profiles, and it is suggested that normalization, peak and asymptotic constraints be imposed on the fit. Numerical tests with both theoretical and simulated experimental data for neon indicate that the expectation values ⟨p -2⟩, ⟨p⟩ and ⟨p 2⟩ can be predicted by the model within 1 per cent accuracy using profile data accurate to 1 per cent and extending up to q≈5 ħa -1 0. An accurate asymptotic constraint is shown to be essential if better than 10 per cent accuracy is to be obtained for ⟨p 3⟩ and ⟨p 4⟩.