Nuclear cross sections data of 209Bi(p, xn)207,206,205,204,203Po, 209Bi(p, pxn)207,206,205,204,203,202Bi, and natPb(p, xn) 206,205,204,203,202,201Bi reactions were measured using the well-known stack-foil activation technique and gamma-ray spectrometry over the 40 to 100 MeV proton energy range. The targets were arranged in different stacks consisting of Bi, Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by activation analysis method using 27Al(p, 3pn)24Na, 197Au(p, pn)196Au, and 197Au(p, p3n)194Au monitor reactions. Around 90 nuclear cross section data points were totally measured in this work.

Furthermore, excitation functions of the mentioned reactions were calculated by using the theoretical models based on the TALYS code and compared to the measured data in this work as well as with other data in the literature. To investigate the effects of various nuclear models on the reaction excitation functions, combinations of the nuclear input parameters of different level density models, optical model potentials, and γ-ray strength functions were considered. It was concluded that the level density models influenced the reaction cross sections significantly.