Ultrarelativistic positronium production in collisions of high energy   electrons and laser photons
  We consider the production of ultrarelativistic parapositronium and orthopositronium atoms in collisions of high energy electrons with laser photons. Our results demonstrate the opportunity of intensive positronium beam formation with Lorentz-factor 10^6 using laser beam conversion on high energy electrons at the future Electron Linear Accelerators. 
A.P.Martynenko, V.A.Saleev