New measurement of residual cross sections from $${\alpha }{+}^{93}$$Nb reaction: a comparative study of PEQ models and nuclear level densities

Abstract

An experimental study of the $${\alpha }{+}^{93}$$Nb reaction has been accomplished within 7–12.5 MeV/nucleon energy. A systematic study of the preequilibrium (PEQ) emission of particles over the compound evaporations has been carried out using the model codes—TALYS1.8 and Alice14. The measured cross sections of $$^{96g,95m+g,94m+g,93g}\hbox {Tc}$$, $$^{93m}\hbox {Mo}$$ and $$^{92m,90g}\hbox {Nb}$$ are found to agree with other reported data within the estimated uncertainties and are grossly reproduced by the theoretical calculations. The variation of isomeric cross-sectional ratio (ICR) of $$^{96,95,94}\hbox {Tc}$$ has been examined up to 100 MeV projectile energy. Additionally, a quantitative analysis of the extent of agreement between measured and theoretical data has been performed for different nuclear level densities using F-deviation factor, which is calculated considering those energies for which experimental cross section is known. Comparison of the measured and theoretical results as well as ICR analysis demonstrates the occurrence of PEQ process in the high-energy tail of excitation functions in all channels, where the compound reaction has a negligible effect.