Measurement of the cross section of the residues from the 11B-induced reaction on 89Y and 93Nb: Production of 97Ru and Rhm101

Background: The heavy-ion induced reactions on intermediate mass targets are complex in nature, even at the low energies. To understand those nuclear reaction phenomena in detail, more experimental studies are required in a wide range of energies.

Purpose: Investigation of heavy-ion reactions by measuring production cross sections of the residues produced in the ¹¹B-induced reactions on ⁸⁹Y and ⁹³Nb at low energies, near and above the barrier, and to check the effectiveness of the different nuclear models to explain them. Further, aim is also to optimize the production parameters of neutron deficient medically relevant ⁹⁷Ru and ^Rhm₁₀₁ radioisotopes produced in those reactions, respectively.

Method: The ¹¹B beam was allowed to impinge on ⁸⁹Y and ⁹³Nb foils supported by an aluminum (Al) catcher foil, arranged in a stack, in 27.5-58.7 and 30.6-62.3 MeV energy range, respectively. The off-line γ -ray spectrometry was carried out after the end of bombardment to measure the activity of the radionuclides produced in each foil and cross sections were calculated. Measured cross-sectional data were analyzed in terms of compound and precompound model calculations.

Results: The measured cross sections of ^Ru,95₉₇, ^96,95,94Tc, ^Mom₉₃, ^Ym₉₀ radionuclides produced in the ¹¹B+⁸⁹Y reaction, and ^101,100,99Pd, ^101m,100,99mRh, ⁹⁷Ru produced in the ¹¹B+⁹³Nb reaction showed good agreement with the model calculations based on the Hauser-Feshbach formulation and exciton model. Unlike theoretical estimation, consistent production of ^Ym₉₀ was observed in the ¹¹B+⁸⁹Y reaction. Substantial pre-equilibrium contribution was noticed in the 3 n reaction channel in both reactions.

Conclusions: Theoretical estimations confirmed that major production yields are mostly contributed by the compound reaction process. Pre-equilibrium emissions contributed at the high energy tail of the 3 n channel for both reactions. Moreover, an indirect signature of a direct reaction influence was also observed in the ^Ym₉₀ production.