On the possible experiments on coherent production of relativistic positronium in a crystal

Generation of relativistic singlet positronium (Ps) atoms by high-energy photons and electrons in amorphous and aligned crystal targets, as well as their break-up due to interaction with target atoms, is considered. The detailed numerical calculations show that due to coherence effect in a crystal target, the significant enhancement of positronium yield, at certain positronium energies and emission angles, can be achieved. The possible experiments with tagged photon beam, with bremsstrahlung (BS) photon beam and electron beam are proposed for planned REFER facility at Hiroshima University. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)