Pressure effect on the compton profile of the some gases

As a result of inelastic collisions of high energy photons with atoms or molecules, the measurements of the Doppler expansion (Compton profile) in the spectra is very important to determine electron momentum distributions of those materials. Although there are a large number of studies in the literature on Compton profile, there are only a few studies demonstrating the effect of the pressure on the electronic structures of matters. Especially, there are no studies related to the pressure-dependent change of electron momentum distributions of gases. In this study, Compton profile measurements of He, Ar, O2, N2 and CO2 gases at different pressures were carried out using a Compton profile Spectrometer having a 5 Ci 241Am radioisotope source and HPGe detector. Our experimental results show that the Compton profiles of gases except for He change with increasing pressure relative to the values measured at 1.0 bar pressure.