Cross sections for (π−, π−n) reactions on 19F and 31P in the 3−3 resonance region

Activation cross sections for the reactions 19F(π−, π−n) 18F and 31P(π−, π−n) 30P were measured at pion energies from 140 to 240 MeV and found to reach maxima of 39 ± 5 mb and 60 ± 11 mb, respectively, near 180 MeV. The results are compared with calculated cross sections and with the results of other measurements.