Measurements of positronium formation cross sections in positron-Mg collisions

Abstract

We report measurements of positronium (Ps) formation cross sections for 0.1\char21{}60 eV positrons scattered by Mg atoms. There is reasonable agreement between the measured cross sections and recent calculations of those values, both of which indicate an unusually steep increase of the Ps formation cross section from zero to a large peak value as the positron energy is increased from the Ps formation threshold to less than 1 eV above that threshold.