The last decade has seen significant progress in low energy trap-based positron beams . New high resolution experimental measurements have been performed for a range of atomic and molecular targets including He , Ne and Ar , Xe, Kr, H2 and H2O . The development of positron beams motivated novel experimental and theoretical studies. While substantial progress has been made for low energy in positron scattering on few-electron targets, considerable theoretical development is still required for multi electron atomic and molecular targets. In this text ,the Schrodinger equation for positron atom collision system is solved numerically and various total cross sections and differential scattering cross sections are calculated for positron scattering by several multi electrons atomic targets. The book is useful for graduate students and academicians , the text discusses fundamentals in the field of positron atom scattering and covers results on multi electrons atomic targets, C,N and O.
