Three-body effects in the annihilation of positrons on molecules

Abstract

The three body effects in the annihilation of positrons on molecules were discussed. The positron annihilation in ethylene gas at room temperature and at densities below one amagat, showed that the mean free positron annihilation rate displayed a density dependence of the form 〈λf〉 = aρ2 + bρ, with a and b constant. The analysis showed that positrons were annihilated in the gas as a result of three-body interactions. © Oxford University Press 2002.