Pion depth-dose distribution including the effect of interactions in flight

The computer design of a toroidal superconducting pion channel is described. The design is aided by means of an interactive graphic display of pion trajectories through the system. Several examples of such pion trajectory groups are presented and these illustrate the focussing quality of the channel under various conditions of interest. The computer ray tracing program is described and listed in the appendix. The final design parameters of pion channel are: solid angle greater than 1 sr, delta p/p of several per cent, and final focal spot dimensions of 1 cm. These parameters are suitable for the proposed applications in cancer therapy