A NEW MODEL OF POSITRONIUM FORMATION - RESONANT POSITRONIUM FORMATION

"Resonant model," a new model of positronium (Ps) formation is proposed. The first stage of Ps formation is the inelastic collisions of e + through formation of an intermediate state (M* .e+) by resonant energy absorption and e+ attachment. The second stage of Ps formation involves thermalized e+ and loosely bound electrons (excess electrons, excited molecules, and certain anions) through resonant electron transfer. Experimental results are reviewed from the viewpoint of the new model comparing it with the older models, the Ore model and the spur model. © 1990 American Institute of Physics.