Investigation of alpha-particles interaction with zirconium: Cross-section measurements and isomeric cross-section...

The α-particle-induced reactions on natural zirconium were investigated to produce ⁹⁹Mo, ^93mMo, ^95mNb, ^95gNb, and ^97gNb using the stacked-foil activation technique, with focus on ⁹⁶Zr(α,n)⁹⁹Mo. While alpha irradiation of natural zirconium offers a straightforward production route, its low yield and the presence of radioimpurities limit its practical application. In contrast, the use of enriched ⁹⁶Zr targets enables the production of radiochemically pure ⁹⁹Mo. Although the achievable activity remains significantly lower than that obtained via reactor- or proton/deuteron-induced routes, the high radiochemical purity and favorable target characteristics of the ⁹⁶Zr(α,n)⁹⁹Mo reaction make it a potential option for localized or small-scale ⁹⁹Mo/^99mTc production. Theoretical calculations for the investigated reactions were performed using EMPIRE 3.2.3 and TALYS-2.0 codes. For the medically important radioisotope ⁹⁹Mo, theoretical modeling was performed using both codes, with an initial exploration of selected input parameters to improve the agreement with experimental data. Despite these refinements, some discrepancies remained, suggesting that further refinement of the model parameters and input data may still be necessary. The isomeric cross-section ratio for the ⁹²Zr(α,p) reaction was measured and analyzed. The experimental data, as well as theoretical calculations, indicate a transition from compound nucleus to pre-equilibrium mechanisms as energy increases.