Setting up of the $\pi$ E3 negative pion beam at SIN for radiobiological irradiations

Some results of preliminary investigations into the feasibility of radiobiological experiments using the biomedical pion beam from the SIN accelerator are reported. They include beam shape central axis depth-dose distributions and pion stopping rates in water using various momentum slit openings. It is shown that both dose and stopping rates are a strong function of depth and depend, in addition, on the momentum spread. Homogeneous exposures of a biological specimen to dose and nuclear products from pion capture limit considerably the size of any biological object that can be irradiated. (4 refs).