Coherent production of relativistic positronium atoms by photons and electrons in a crystal

Theory of coherent type B positronium atom production by high energy photon and relativistic electron in a real (three dimensional) crystal has been developed. On the base of developed theory the orientation dependence of cross-section is studied. It is shown, that small change of the photon energy in the vicinity of coherent peak results in change of character of the coherent type B Ps photoproduction orientation dependence.