Excess flux of secondary anti-protons assuming interstellar fractal medium

Among the anti-particles of cosmic rays، anti-protons are of particular importance. In cosmic ray spectrum، the major part of anti-protons is outcome of collision of cosmic rays with interstellar medium gas. Considering the non-homogenous or fractal interstellar medium، proposed by Lagutinet. al.، excess flux of secondary anti-protons is calculated. This excess flux is the probable component of extra galactic anti-protons. In addition، the ratio of extra galactic and galactic anti protons to cosmic rays protons flux is calculated as a reason for matter and anti-matter asymmetry and also energy density of extra galactic anti protons.