*Department of Physics, Invertis University, Bareilly (U.P.) -243 123 (India)
Department of Physics, Bareilly College, Bareilly (U.P.) – 243 005 (India)
E-mails: kamlesh.fphiiet@gmail.com,     sanjeev.sxn@gmail.com

We have computed differential cross section (DCS) for ionization of noble gas atoms by impact of positron (electron) using truncated coupled state Born approximation (TCSBA). High quality Hartree-Fock Slater orbitals are used to model the target wave function. We have already computed some ionization results1, 2, & 3 for noble gas series by impact of positron and electron as well, but in this paper, we are presenting for Ne, Ar, Kr & Xe atoms. We have compared DCS
results with other available theoretical results as well as experimental data. It is observed that full orthogonalization of target wave function significantly improves present results and provides better agreement with experimental data for the noble gas series. Our present results are found in excellent agreement with other calculations. However some discrepancies suggested that more theoretical as well as experimental work is required in future to improve the data.