PHOCHA: a Monte Carlo program to calculate the caracteristics of a beam of photons produced by annihilation and bremsstrahlung of relativistic positrons

The program PHOCHA calculates the absolute energy spectra, the radial and vertical profiles and the angular distributions of annihilation and bremsstrahlung photons from intermediate energy positrons. The energy spread, the energy loss and the multiple scattering of the positrons in the annihilation target are taken into account. Moreover the positron emittance, the positron incidence angle and the finite angular acceptance of the photon collimation channel are explicitly considered. (orig.)