Collision Models for F -Ar, F -Kr, and F -Xe are obtained using the Monte Carlo technique. The models are determined by comparing the calculated drift velocities of Fion in Ar, Kr, and Xe gases with the measured data in a wide range of reduced electric field E=N of 2-500 Td (1 Td = 10 21 Vm 2 ). The present models are applicable to the particle modeling for the