On the accuracy of the BGK model for ion drift in own gas

The model of collisions of ions with gas atoms, considering resonant charge exchange of ions, polarization and elastic (gas-kinetic) interactions is constructed. Ion drift characteristics in the dc electric field are calculated. The results are compared to calculations based on the Bhatnagar-Gross-Krook model collision integral (BGK integral). It is shown that the use of the BGK collision integral leads to significant errors due to the specificity of ion-atom collisions.