Modified model of optical positron

Positron annihilation from positron-anion bound state is considered. Critical analysis of optical positron model is given and its modification is proposed to eliminate the drawbacks of this model. Calculation of angular correlation curves and positron lifetime is performed. Positron repulsive forces from nuclei, dominating under minor distances are taken into account in the calculation. It is shown, that the anion internal electrons do not play an important role in the formation of angular correlation resulting curve and do not effect the positron lifetime duration. The model allows one to determine the anion effective charges and the value of the positron repulsive force from the nucleus by the angular correlation experimental curves and the positron lifetime in ionic media. The analysis is conducted particularly for O2- ion