MAGNETIC EFFECTS ON POSITRONIUM FORMATION AND ANNIHILATION IN ORGANIC LIQUIDS

It was recently found that an external magnetic field markedly enhances the orthopositronium annihilation rate in certain organic solutions above and beyond that expected for the Zeeman effect. Several solutions have been studied, but the effect has been found only for nitrobenzene in n-hexane. A mechanism for this is proposed and tested numerically with a kinetics scheme modified to include nonhomogeneous spur effects. The mechanism features the quenching of orthopositronium by a short-lived triplet solute species, the concentration of which is moderated by the applied magnetic field.