AMOS – An effective tool for adjoint Monte Carlo photon transport

In order to expand the photon version of the Monte Carlo transport program AMOS to an adjoint photon version, AMOS Pt, the theory of adjoint radiation transport is reviewed and evaluated in this regard. All relevant photon interactions, photoelectric effect, coherent scattering, incoherent scattering and pair production, are taken into account as proposed in the EPDL 97. In order to simulate pair production and to realise physical source terms with discrete energy levels, an energy point detector is used. To demonstrate the qualification of AMOS Pt a simple air-over-ground problem is simulated by both the forward and the adjoint programs. The results are compared and total agreement is shown.