Specific features of position annihilation in aqueous solutions of alkali metal halides

The process of positron annihilation in aqueous solutions of NaF, NaCl, NaBr, NaI in a wide range of concentrations was studied experimentally. Various annihilation channels were identified, their contribution into entire process, depending on the nature and content of halide ions, was determined. A model is suggested, according to which positrons form with halide ions complexes with different lifetimes. calculations using the model show a good agreement with experimental results. Probabilities of formation of different position and positronium states and their lifetime were estimated