Production and scattering of a positronium beam

Progress in the field of positronium beam-production and scattering is reviewed. A useful beam of positronium is obtained in the energy range 10-250 eV by scattering positrons from H2 and N2. With such a beam, total positronium - atom/molecule scattering cross-sections and integrated and differential fragmentation cross-sections have been measured. Results are presented and compared with recent theoretical determinations. First results for the absolute differential positronium formation cross-sections are also presented.