Measurement of the cross section of the residues from the ${}^{11}\mathrm{B}$-induced reaction on ${}^{89}\mathrm{Y}$ and ${}^{93}\mathrm{Nb}$: Production of ${}^{97}\mathrm{Ru}$ and ${}^{101m}\mathrm{Rh}$

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 ${}^{11}\mathrm{B}$-induced reactions on ${}^{89}\mathrm{Y}$ and ${}^{93}\mathrm{Nb}$ 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 ${}^{97}\mathrm{Ru}$ and ${}^{101m}\mathrm{Rh}$ radioisotopes produced in those reactions, respectively.

Method: The ${}^{11}\mathrm{B}$ beam was allowed to impinge on ${}^{89}\mathrm{Y}$ and ${}^{93}\mathrm{Nb}$ 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 $\gamma$-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 ${}^{97,95}\mathrm{Ru}$, ${}^{96,95,94}\mathrm{Tc}$, ${}^{93m}\mathrm{Mo}$, ${}^{90m}\mathrm{Y}$ radionuclides produced in the ${}^{11}\mathrm{B}$+${}^{89}\mathrm{Y}$ reaction, and ${}^{101,100,99}\mathrm{Pd}$, ${}^{101m,100,99m}\mathrm{Rh}$, ${}^{97}\mathrm{Ru}$ produced in the ${}^{11}\mathrm{B}$+${}^{93}\mathrm{Nb}$ reaction showed good agreement with the model calculations based on the Hauser-Feshbach formulation and exciton model. Unlike theoretical estimation, consistent production of ${}^{90m}\mathrm{Y}$ was observed in the ${}^{11}\mathrm{B}$+${}^{89}\mathrm{Y}$ reaction. Substantial pre-equilibrium contribution was noticed in the $3n$ 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 $3n$ channel for both reactions. Moreover, an indirect signature of a direct reaction influence was also observed in the ${}^{90m}\mathrm{Y}$ production.

Figure 1

A schematic diagram of a typical stack foil activation setup.

Figure 2

A $\gamma$-ray spectrum of the ${}^{11}\mathrm{B}$+${}^{89}\mathrm{Y}$ reaction at 50.8 MeV energy after 38.3 min of EOB.

Figure 3

A $\gamma$-ray spectrum of the ${}^{11}\mathrm{B}$+${}^{93}\mathrm{Nb}$ reaction at 51 MeV energy after 37.9 min of EOB.

Figure 4

Comparison of measured excitation function (symbols) of ${}^{97}\mathrm{Ru}$ from the ${}^{11}\mathrm{B}$+${}^{89}\mathrm{Y}$ reaction and those computed from the theory (curves) using empire and pace4.

Figure 5

Comparison of measured (symbols) and computed (curves) excitation functions for production of ${}^{95}\mathrm{Ru}$.

Figure 6

Same as Fig. 5 for ${}^{96}\mathrm{Tc}$.

Figure 7

Same as Fig. 5 for ${}^{95}\mathrm{Tc}$.

Figure 8

Same as Fig. 5 for ${}^{94}\mathrm{Tc}$.

Figure 9

Same as Fig. 5 for ${}^{93m}\mathrm{Mo}$.

Figure 10

Same as Fig. 5 for ${}^{90m}\mathrm{Y}$.

Figure 11

Comparison of measured excitation function (symbols) of ${}^{101}\mathrm{Pd}$ from the ${}^{11}\mathrm{B}$+${}^{93}\mathrm{Nb}$ reaction and those computed from theory (curves) using empire and pace4.

Figure 12

Same as Fig. 11 for ${}^{100}\mathrm{Pd}$.

Figure 13

Same as Fig. 11 for ${}^{99}\mathrm{Pd}$.

Figure 14

Cumulative production of ${}^{101m}\mathrm{Rh}$, via its higher charge isobar, ${}^{101}\mathrm{Pd}$ (8.47 h) with the passage of time at various incident energies.

Figure 15

Same as Fig. 11 for ${}^{101m}\mathrm{Rh}$.

Figure 16

Same as Fig. 11 for ${}^{100}\mathrm{Rh}$.

Figure 17

Same as Fig. 11 for ${}^{99m}\mathrm{Rh}$.

Figure 18

Same as Fig. 11 for ${}^{97}\mathrm{Ru}$.