Products of stopped-pion interactions with Cu and Ta

Yields of radioactive products from the interactions of stopped π- with Cu and Ta have been measured. Absolute yields of products ranging down to 10-5 per stop were determined. The experimental yields are compared with yields calculated with a model that was developed in this work for the stopped-π- interaction. The calculations give excellent agreement with measured total mass yields for Ta, but some discrepancies exist for the independent yields of Hf, Er, and Tm isotopes; in the case of Cu, most independent yields, except for Co and Sc, are in good agreement. Measurements were also made with both stopped π- and 20-MeV π+ on Cu and Fe to determine the shift in the centroids of the isotopic yields with pion charge