  A cascade model has been developed to study pion induced multichannel
reactions (quasielastic, SCX, DCX, absorption and pion production) at pion
energies above 0.5 GeV. Special attention has been paid to pion double charge
exchange. Pion production is a determinant feature in the high energy pion
nucleus reactions, and the DCX signal not related to pion production is
sizeable only at forward angles and for high energy outgoing pions. The
contribution to DCX of the conventional mechanism, with two quasielastic SCX
steps decreases very fast as a function of the energy and reaches very low
values at energies above 0.7 GeV. This opens the opportunity of having sizeable
contributions of exotic mechanisms that are negligible at the delta resonance
energies.
