Bethe surface and Compton profile of NH3 obtained by 35 keV electron impact

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Abstract
Complete inelastic electron impact spectra have been obtained for NH3 for a momentum transfer range from 0.4 to 12.5 a.u. using 35 keV electrons. These spectra were converted to relative generalized oscillator strengths (GOS), were placed onto an absolute scale by the Bethe sum rule, and higher order sum rules were used to test the accuracy of the GOS. The Compton profile (CP) of NH3 was determined from the GOS by means of the impulse approximation (IA) and it was found that the CP’s were asymmetric and shifted in respect to the free electron theoretical CP. This Compton defect was analyzed in detail and was shown to be due to the failure of the IA. The area under the CP is discussed in terms of the x‐ray incoherent scattering factor and experimental results for the valence, inner shell, and total CP’s are compared to several theoretical profiles.