Electron impact ionisation cross sections derived from total inelastic cross section for CF3X and CF2X2(X = H, Cl, Br and I) molecules

We report here the total ionisation cross sections for CF3X and CF2X2 (X = H, Cl, Br and I) molecules by electron impact from ionisation threshold to 5 keV. The total inelastic cross section is obtained employing a quantum mechanical approach called spherical complex optical potential formalism. Then, using a semi-empirical complex scattering potential-ionisation contribution method, the ionisation cross section is derived from the inelastic cross section. The results obtained are compared with previous measurements and theoretical values, wherever available and a satisfactorily agreement is observed. The ionisation cross section values for CF2I2 molecule are reported for the first time.