Positronium in a Liquid Phase : Formation, Bubble State and Chemical Reactions

Abstract EN

The present approach describes the e+ fate since its injection into a liquid until its annihilation.

Several stages of the e+ evolution are discussed: (1) energy deposition and track structure of fast positrons: ionization slowing down, number of ion-electron pairs, typical sizes, thermalization, electrostatic interaction between e+ and the constituents of its blob, and effect of local heating; (2) positronium formation in condensed media: the Ore model, quasifree Ps state, intratrack mechanism of Ps formation; (3) fast intratrack diffusion-controlled reactions: Ps oxidation and ortho-paraconversion by radiolytic products, reaction rate constants, and interpretation of the PAL spectra in water at different temperatures; (4) Ps bubble models.

Inner structure of positronium (wave function, energy contributions, relationship between the pick-off annihilation rate and the bubble radius).