  A study of the gas pressure effect in the position resolution of an
interacting X- or gamma-ray photon in a gas medium is performed. The intrinsic
position resolution for pure noble gases (Argon and Xenon) and their mixtures
with CO2 and CH4 were calculated for several gas pressures (1-10bar) and for
photon energies between 5.4 and 60.0 keV, being possible to establish a linear
match between the intrinsic position resolution and the inverse of the gas
pressure in that energy range. In order to evaluate the quality of the method
here described, a comparison between the available experimental data and the
calculated one in this work, is done and discussed. In the majority of the
cases, a strong agreement is observed.
