Analysis of excitation functions for alpha particle-induced reactions on stable copper and antimony isotopes up to 80 MeV energy region

Analysis of excitation functions for alpha particleinduced reactions on stable copper and antimony isotopes up to 80 MeV energy region Cherie Sisay Mekonen1, A. V. Mohan Rao2, Yohannes Amare Dessie2 1 Department of Physics, College of Natural and Computational Science, Woldia University, Woldia, Ethiopia 2 Department of Physics, College of Natural and Computational Science, University of Gondar, Gondar, Ethiopia Corresponding author: Cherie Sisay Mekonen ([email protected]) Academic editor: Anton Smirnov ♦ Received 10 June 2025 ♦ Accepted 25 September 2025 ♦ Published 14 November 2025 Citation: Mekonen CS, Rao AVM, Dessie YA (2025) Analysis of excitation functions for alpha particle-induced reactions on stable copper and antimony isotopes up to 80 MeV energy region. Nuclear Energy and Technology 11(4): 259–269. https://doi.org/10.3897/ nucet.11.155986 Abstract This study applies the COMPLET nuclear reaction code to calculate excitation functions for eleven alpha-induced reactions on stable copper (63Cu, 65Cu) and antimony (121Sb, 123Sb) isotopes, aiming to predict production cross-sections for medically significant radionuclides such as 68Ga, 67Ga, 66Ga, 65Zn, 124I, and 123I. Reactions are simulated across an alpha energy range of 10–80 MeV to evaluate excitation functions. Fixed nuclear model parameters, such as an initial exciton number n0 = 4 (2p+2n+0h) and level density parameters ACN/K (K = 10) expressions tied to compound nucleus mass, were used to compute theoretical cross-sections. Model outputs were systematically compared with experimental data obtained from the EXFOR database. Statistical and graphical analyses demonstrated an excellent agreement, with Pearson correlation coefficients ranging from 0.74 to 0.94. Sensitivity analyses confirmed that variations in exciton numbers and level density parameters significantly influenced the shape and peak positions of the excitation functions, highlighting the importance of accurate parameter selection. These findings validate the COMPLET code as a reliable tool for modeling alpha-induced nuclear reactions, especially when experimental data are scarce. The results contribute to improved nuclear data evaluations and provide critical support for the planning of radionuclide production in medical applications. The study also includes a detailed covariance analysis to minimize discrepancies between model predictions and experimental data, emphasizing the importance of theoretical methods in contemporary nuclear research. Keywords COMPLET code, alpha-induced reactions, excitation function, Pearson correlation, copper isotopes, antimony isotopes, medical radionuclides Introduction Nuclear cross-sections are fundamental to understanding the probability of nuclear reactions and underpin both theoretical and applied nuclear science. Advancing nuclear reaction theory requires a strong understanding of nucleonand alpha-induced processes, which are essential for accurate modeling and practical applications. Alpha-induced reactions on stable isotopes are especially significant for producing medical radionuclides and testing nuclear models. Comprehensive nuclear data, particularly excitation functions, are essential for practical applications listed in concrete application areas, such as nuclear medicine, Copyright Mekonen CS et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Nuclear Energy and Technology 11(4): 259–269 DOI 10.3897/nucet.11.155986 Research Article Mekonen CS et al.: Analysis of excitation functions of alpha particle induced reactions260 materials science, and reactor technology. These data support both theoretical modeling and practical implementation across disciplines (Otuka et al. 2014; Karpuz Demir et al. 2017; Qaim 2017; Hilaire et al. 2018; Alhassid 2021; Qaim et al. 2021; Kolos et al. 2022). Recent advancements in nuclear reaction modeling, particularly through codes like COMPLET, have significantly enhanced the simulation of compound nucleus formation and pre-equilibrium processes. These tools offer valuable theoretical support for experimental design and nuclear data evaluations. Alpha-induced reactions are particularly important for testing and refining these models, especially in the intermediate energy range of 10–80 MeV, where both direct and pre-equilibrium mechanisms play substantial roles in shaping cross-section behavior. Even so, despite their importance, experimental cross-section data for alphainduced reactions remain scarce. This is especially true for specific channels such as (α,n) and (α,pn), which have limited data coverage due to the high cost, radiation safety concerns, and technical challenges of alpha irradiation experiments (Escher et al. 2012; Semkova and Pritychenko 2014; Artun and Aytekin 2017; Yiğit 2018; Zerkin and Pritychenko 2018). According to the IAEA (Schwerer and Obložinský 2001), combining theoretical models with available experimental data enhances the accuracy and interpretation of nuclear reaction results. This approach is particularly valuable for data evaluation and for optimizing the production of medical isotopes. As a result, there is a growing demand for reliable and predictive nuclear models to bridge data gaps and support applications in nuclear medicine and technology. In this work, among potential target materials, copper (63Cu, 65Cu) and antimony (121Sb, 123Sb) are of particular interest due to their natural abundance and capacity to produce key medical isotopes such as 68Ga, 67Ga, 66Ga, 65Zn, 123I, and 124I. The growing need for medical radioisotopes is increasing pressure to arrive at more effective production routes for clinically relevant isotopes. These products play a critical role in diagnostic imaging and therapeutic radiotherapy, particularly in Positron Emission Tomography (PET) and other nuclear medicine applications (Green 1991; Pneumaticos et al. 2001; Jalilian et al. 2006, 2016; Braghirolli et al. 2014; Cascini et al. 2014). Ensuring a consistent supply of medical isotopes depends heavily on well-established production routes and validated modeling approaches, as reported by recent studies (Sabet et al. 2006; Braghirolli et al. 2014; Resongles et al. 2015; Leonte et al. 2020; Noori 2025; (Wen et al. 2018). Accurately modeling reactions on these targets helps develop more efficient methods for producing radionuclides. Our theoretical calculations focus on alpha-induced nuclear reactions on copper and antimony isotopes, employing the COMPLET nuclear reaction code. The COMPLET computer code is an enhanced and updated extension of the ALICE code family. COMPLET integrates deterministic models, using the Weisskopf–Ewing formalism for compound nucleus formation and the geometry-dependent hybrid (GDH) model for pre-equilibrium emission. It incorporates additional physical models, corrections, and features, making it suitable for predicting production cross-sections (Asres et al. 2018; Mekonen and Rao 2023; Degu Belete et al. 2024). To evaluate the accuracy of these predictions, we conducted a systematic comparison with experimental cross-section data retrieved from the EXFOR database (Zerkin and Pritychenko 2018; Pritychenko 2023). This validation process helps quantify discrepancies and assess the model’s reliability in reproducing observed reaction behavior. Such comparisons are essential for understanding reaction mechanisms and improving the predictive capabilities of nuclear reaction models. These enhancements allow the code to simulate complex nuclear interactions at incident alpha energies up to several hundred MeV (Mekonen and Rao 2023). This study addresses the lack of cross-section data by calculating excitation functions for eleven alpha-induced reactions involving stable isotopes of copper (63Cu, 65Cu) and antimony (121Sb, 123Sb) across the given energy range. Beyond evaluating excitation functions, the study conducts a sensitivity analysis of key nuclear model parameters and applies Pearson correlation coefficients to quantify the agreement between theoretical predictions and experimental data. We compare results from model calculations with available experimental data for EXFOR library. By integrating advanced nuclear reaction modeling with experimental validation, this work contributes to the accurate prediction of cross-sections needed for both theoretical nuclear physics and practical applications in nuclear medicine. The results support improved radionuclide production planning and provide a foundation for future investigations targeting data-scarce alpha-induced reactions. Materials and methods Computational Modeling Using COMPLET This study uses the COMPLET nuclear reaction code to calculate excitation functions for eleven alpha-induced reactions on stable copper (63Cu, 65Cu) and antimony (121Sb, 123Sb) isotopes. COMPLET is a FORTRAN-based tool that extends the ALICE-91 framework with enhanced nuclear reaction models, including compound and pre-equilibrium mechanisms (Asres et al. 2018; Asreset al. 2019; Cherie Sisay and Teshagre Aklie 2023; Tiguaded and Amanuel 2024; Degu Belete et al. 2024; Ejersoet al. 2023; Yiǧit and Tel 2014). As a modular software system, COMPLET supports a wide range of projectiles and energies and integrates key nuclear structure models, Nuclear Energy and Technology 11(4): 259–269 261 including mass predictions, level densities, discrete energy levels, photon strength functions, and fission barriers. This comprehensive modeling approach enables detailed predictions of reaction observables, making COMPLET valuable for both theoretical investigations and applied nuclear science, including reactor design and the production of medical isotopes. Model predictions were validated against experimental cross-sections retrieved from the EXFOR database (Zerkin and Pritychenko 2018). Pearson correlation coefficients (R-values) were calculated to quantify the agreement between theoretical and experimental results. The COMPLET nuclear reaction code is a theoretical modeling tool based on the exciton model and geometry-dependent hybrid (GDH) formalism (Weisskopf and Ewing 1940; Blann and Vonach 1983; Hodgson et al. 1986). It models the early stages and overall processes in nuclear reactions, especially for light particles such as protons, deuterons, and alpha particles. COMPLET calculates excitation functions and reaction cross sections using adjustable parameters such as exciton number and level density. It is widely used in nuclear data evaluation when experimental measurements are limited (Artun and Aytekin 2017; Yiğit 2018; Mekonen and Rao 2023). Key capabilities of the COMPLET code include: • Wide energy applicability: It simulates nuclear reactions from 10 MeV to 300 MeV, making it suitable for both lowand intermediate-energy nuclear studies. • Broad target range: The code applies to nuclei with mass numbers (A) ≥ 12, covering light to heavy elements relevant in medical and industrial applications. • Multiple projectile support: It supports a variety of incident particles, including neutrons, protons, deuterons, tritons, helium-3, alpha particles, and photons, making it versatile for diverse nuclear scenarios. • Cross-section calculations: COMPLET predicts both total and partial reaction cross-sections, offering valuable data for theoretical analysis and experimental comparison. Unified reaction mechanism treatment: It simultaneously handles compound, pre-equilibrium, and direct reactions, enabling a more complete representation of nuclear processes. • Applications in radionuclide production: COMPLET supports the modeling of reaction pathways relevant to the production of medically important radionuclides, such as 68,67,66Ga, 65Zn, and 123,124I isotopes. With its integrated theoretical models and extended functionalities, COMPLET is a reliable tool for nuclear data evaluation, theoretical predictions, and the optimization of radionuclide production routes. Input parameters and reaction modeling Table 1 lists the principal model input parameters used in the simulations. These were optimized to achieve agreement with experimental data for each reaction channel. The sensitivity of the exciton model was analyzed by varying the initial exciton number (n0 = 4, 5, 6), following guidance from Rao et al. (1991) and Aydin et al. (2007). To ensure the best match with experimental data (Figs 1–11), the optimal exciton number for each reaction was determined using a fitting method. Additionally, the level density parameter was defined as a = ACN/K, where ACN is the mass number of the compound nucleus and K is an adjustable constant ranging from 8 to 10, as suggested by (Akkoyun et al. 2015). The best-fit values of n₀ and K for each reaction were determined by comparing the calculated excitation functions with experimental data. These parameter adjustments had a significant impact on both the shape and peak positions of the excitation functions, confirming their influence on the model’s predictive accuracy (Elmaghraby 2008; Tel et al. 2008; Furutachi et al. 2019; Najm and Salloum 2025). For each reaction, the input parameters, including level density models and optical model potentials were optimized to improve agreement with experimental cross-section data. Experimental data sources Experimental cross-section data were obtained from the IAEA’s EXFOR database (Pritychenko 2023), which compiles peer-reviewed measurements of nuclear reactions. For each reaction studied, relevant literature sources were referenced to support comparative analysis. EXFOR, run by the IAEA, was used as the main source of experimental cross-section data (IAEA 1994; Schwerer et al. 2003; Dupont et al. 2011; Otuka et al. 2014). Table 1. Key COMPLET input parameters used in this study. Parameter Description Value(s) used Projectile energy range Alpha particle energy 10–80 MeV Reaction types α + target → xn, pn 11 channels (Cu, Sb targets) Initial exciton number n0Pre-equilibrium configuration (p, h, α) (2p, 2h, 0α) → n0 = 4 Level density parameter a a = ACN/K, where K = 8–10 K = 10 Models used Compound + pre-equilibrium emission Weisskopf–Ewing, GDH Emission particles n, p, α, γ Channel-dependent Mekonen CS et al.: Analysis of excitation functions of alpha particle induced reactions262 Correlation analysis To assess the agreement between theoretical and experimental results, the Pearson correlation coefficient (R) was calculated using the following formula (Baak et al. 2020): Where: Xti, Xei are the theoretical and experimental cross-sections for the i-th data point; X t, X e are the means of the theoretical and experimental values; SXe, SXt are their respective standard deviations; N is the number of data points. In this study, the strength of agreement between theoretical predictions and experimental data is assessed using the Pearson correlation coefficient (R) (Mekonen and Rao 2023). The R-values typically follow standard thresholds. The R-values are interpreted based on standard thresholds: • R > 0.9 indicates an excellent correlation. • 0.7 < R ≤ 0.9 indicates a strong correlation. • 0.5 < R ≤ 0.7 indicates a moderate correlation. • 0.3 < R ≤ 0.5 indicates a weak correlation. • R ≤ 0.3 indicates a very weak or no correlation. Data visualization All graphs were generated using Origin-Lab and Microsoft Excel, ensuring consistent formatting for energy (MeV) and cross-section (mb) values. Radionuclide symbols were properly displayed using scientific notation (e.g., 68Ga, 123I). Each figure presents experimental data points alongside theoretical curves calculated using the COMPLET code. Data availability The data underpinning this study is publicly available at Zenodo https://doi.org/10.5281/zenodo.17202575 (version 1: https://doi.org/10.5281/zenodo.17202576). Additional data or specific requests can also be obtained from the corresponding author upon reasonable request. Result and discussion This section presents the excitation functions of 11 alpha-induced nuclear reactions on copper (63Cu, 65Cu) and antimony (121Sb, 123Sb) isotopes, calculated using the COMPLET nuclear reaction code. Theoretical results are benchmarked against experimental data from the EXFOR database. Special attention is given to medically significant radionuclides, including 68Ga, 67Ga, 65Zn, 124I, and 123I, due to their critical roles in diagnostic imaging and radiotherapy. Quantitative comparison is performed using the Pearson correlation coefficient (R), where values above 0.7 indicate strong agreement between theoretical predictions and experimental measurements. The COMPLET code was used to analytically compare the theoretical results with previously published data. Gallium isotope production The excitation functions for alpha-induced reactions in Copper (Cu) nuclei were calculated theoretically using the COMPLET code. Four specific reactions were analyzed: 63Cu (α, n) 66Ga, 63Cu (α, 2n) 65Ga, 65Cu (α, n) 68Ga and 65Cu(α,2n) 67Ga. The theoretical results were compared with experimental data and presented in Figs 1–4. 66Ga via 63Cu (α, n) reaction (Fig. 1) Our theoretical calculations for the 63Cu (α,n)66Ga nuclear reaction demonstrate strong consistency (align closely) with the existing experimental data across an energy range, particularly above 33 MeV. Experimental data from (Singh et al. 1994; Levkovskii et al. 1984; Bryant et al. 1963; Rizvi et al. 1987; Zhukova et al. 1970) show an excellent correlation with theoretical results (R = 0.92), confirming the model’s reliability in this energy region. This high level of agreement suggests that the COMPLET code effectively captures the dominant reaction mechanisms, especially in the energy region above the reaction threshold. The (α,n) reaction pathway is straightforward, resulting in lower sensitivity to modeling assumptions and parameters. High-quality experimental data help fine-tune model parameters and make the excitation functions more reliable. 65Ga via 63Cu (α,2n) reaction (Fig. 2) For the 63Cu (α,2n) 65Ga reaction, our calculations show good agreement with experimental data reported by (Levkovskii et al. 1984; Morrison and Porile 1959; Navin et al. 2004; Porile and Morrison 1959) (Rossi n.d., 10 15 20 25 30 35 40 45 0 100 200 300 400 500 600 700 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) E.A.Bryant et al. (1963) O.A.Zhukova et al. (1970) I.A.Rizvi et al. (1987) V.N.Levkovski (1991) N.L.Singh et al. (1994) Excitation Function of the 63 Cu(α,n) 66 Ga Reacction Figure 1. Our cross-section calculations of 63Cu (α,n)66Ga reaction compared with experimental data. Nuclear Energy and Technology 11(4): 259–269 263 Morrison and Porile 1959; Levkovskii et al. 1984; Navin et al. 2004). Although some deviations are noted at lower energies, agreement improves significantly beyond 40 MeV. The (α,2n) reaction on 63Cu yielded an R-value of 0.78, indicating a strong but not excellent agreement between theoretical predictions and experimental data. This moderate deviation may result from limits in modeling pre-equilibrium emission, sensitivity to level density, or competing reaction effects. Additionally, sparse or scattered experimental data in the threshold and peak regions can contribute to reduced correlation. Fine-tuning input parameters or applying hybrid model comparisons may enhance predictive accuracy. 68Ga via 65Cu (α,n) reaction (Fig. 3) Theoretical excitation functions for 65Cu(α,n)68Ga are consistent with experimental data from multiple studies (Levkovskii et al. 1984; Singh and Patel 1994; Szelecsényi et al. 2012; Hermanne et al. 2015; Uddin and Scholten 2016). At higher energy ranges, the COMPLET results align well with experimental data and effectively replicate the peak structure. The high Pearson coefficient (R = 0.94) highlights the predictive strength of COMPLET for this channel. This excellent agreement reflects the model’s capability to reproduce both the peak position and magnitude of the cross-section curve. The predictive accuracy stems from well-defined nuclear structure parameters for 68Ga and the availability of consistent experimental datasets. The observed consistency validates the reliability of the COMPLET framework in simulating neutron-emission channels for copper isotopes at intermediate alpha energies. 67Ga via 65Cu(α,2n) reaction (Fig. 4) Fig. 4 illustrates the excitation function for the 65Cu (α,2n) 67Ga reaction. Although the model slightly underestimates the peak cross-section, the overall shape and trend align well with the experimental data reported by (Bonesso et al. 1991; Singh and Patel 1994; Levkovskii et al. 1984; Rizvi et al. 1987; Porile and David 1959). The calculated results closely match the experimental data, yielding a correlation coefficient of R = 0.86. The cross-section shows a pronounced peak, reaching a maximum in both the reported experimental data and our calculations. Beyond 48 MeV, the results exhibit strong agreement, with noticeable overlap at the high-energy tail. Zinc and iodine isotope production Excitation functions for alpha-induced reactions in Copper and Antimony nuclei were calculated theoretically using the nuclear reaction simulation code. Seven specific reactions were analyzed: 63Cu(α,pn) 65Zn, 123Sb (α, n) 126I, 121Sb (α, n) 124I, 123Sb(α,3n) 124I, 121Sb(α,2n) 123I, 123Sb(α,4n) 123I and 121Sb (α, 4n) 121I. These theoretical calculations were compared with experimental data from the EXFOR library which were plotted in Figs 5–11. 20 25 30 35 40 45 0 100 200 300 400 500 600 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) N.T.Porile & D.L.Morrison (1959) D.L.Morrison & N.T.Porile (1959) V.N.Levkovski (1991) A.Navin et al. (2004) Excitation Function of the 63 Cu(α,2n) 65 Ga Reaction Figure 2. Our cross-section calculations of 63Cu (α,2n)65Ga reaction compared with experimental data. 10 20 30 40 50 60 70 0 200 400 600 800 1000 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) V.N.Levkovski (1991) N.L.Singh et al. (1994) S.Mukherjee et al. (1997) F.Szelecsenyi et al. (2012) A.Hermanne et al. (2015) Excitation Function of the 65 Cu(α,n) 68 Ga Reaction Figure 3. Our cross-section calculations of 65Ga (α,n)68Ga reaction compared with experimental data. 10 20 30 40 50 60 70 0 200 400 600 800 1000 1200 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) O.A.Zhukova et al. (1970) I.A.Rizvi et al. (1987) O.Bonesso et al. (1991) V.N.Levkovski et al. (1991) N.L.Singh et al. (1994) Excitation Function of the 65 Cu(α,2n) 67 Ga Reaction Figure 4. Our cross-section calculations of 65Cu (α,2n)67Ga reaction compared with experimental data. Mekonen CS et al.: Analysis of excitation functions of alpha particle induced reactions264 65Zn via 63Cu(α,pn) reaction (Fig. 5) Analysis of the 63Cu (α,pn) 65Zn reaction shows good agreement or align reasonably with experimental cross-sections, particularly in the mid-energy region. Comparison with datasets from (Singh and Patel 1994; Pipit Muliyah et al. 2020; Porile and David 1959; Zweit et al. 1987) yields a Pearson correlation coefficient of R = 0.81, indicating reliable predictive performance. While this correlation is slightly lower than that of simpler reaction channels such as (α,n), it reflects the added complexity of the (α,pn) mechanism, which involves both proton and neutron emission. Because the (α,pn) reaction is more complex, the model becomes more sensitive to inputs like pre-equilibrium emission and optical potentials, leading to slight deviations at specific energies. Despite these challenges, the model successfully reproduces the overall trend of the excitation function, demonstrating its reliability in simulating (α,pn) reactions and providing valuable theoretical guidance in the absence of recent experimental data. 124I via 121Sb (α,n) and 123Sb (α,3n) reactions (Figs 6, 7) We conducted theoretical calculations for both the 121Sb (α,n) 124I and 123Sb(α,3n) 124I reaction channels to evaluate their cross-section behavior. Our theoretical calculations for this reaction show strong agreement with experimental data reported by (Hassan et al. 2006; Singh and Bhardwaj’ 1991; Ismail 1990; Singh et al. 2006; Uddin et al. 2010; Bhardwaj 1994). Both the experimental data and our calculations display a pronounced peak in the 30–40 MeV energy range, with cross-sections exceeding 1000 mb. While the experimental cross-sections are generally higher than our calculated values, the overall trends remain consistent across the energy range. The Pearson correlation coefficients for the 121Sb and 123Sb reactions are 0.88 and 0.91, respectively, indicating a high level of agreement between theoretical and experimental results and demonstrating the model’s reliability for both reaction channels despite differences in the target isotopes. 123I via 121Sb (α,2n) and 123Sb (α,4n) reactions (Figs 8, 9) We presented the calculated excitation functions alongside experimental data for the production of the radioisotope 123I in Figs 8, 9. All measured data reported by (Hassan et al. 2006; Singh and BhardwaJ’ 1991; Ismail 1990; Singh and Bhardwaj’ 1991) show close alignment with our results, except for one outlier from Bhardwaj (1994). The model generates smooth excitation curves and accurately predicts peak positions in close agreement with the experimental values. Notably, strong agreement is observed in the peak regions of the excitation functions, although some deviations appear at lower energies. The model closely matches peak values but shows minor deviations at lower energies. Although the target isotopes and reaction mechanisms differ, the average Pearson correlation coefficient remains high (R = 0.87), showing that the model is reliable. 15 20 25 30 35 40 0 200 400 600 800 1000 1200 1400 1600 1800 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) N.T.Porile & D.L.Morrison (1959) F.H.Ruddy (1968) O.A.Zhukova et al. (1970) J.Zweit (1987) N.L.Singh et al. (1994) Excitation Function of the 63Cu(α,pn)65Zn Reaction Figure 5. Our cross-section calculations of 63Cu (α,pn)65Zn reaction compared with experimental data. 10 20 30 40 50 -50 0 50 100 150 200 250 300 350 400 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) K.F.Hassanet al. (2006) M.Ismail (1990) B.P.Singh et al. (1991) B.P.Singh et al. (2006) Excitation Function of 121 Sb(α,n) 124 I Reaction Figure 6. Our cross-section calculations of 121Sb (α,n)124I reaction compared with experimental data. 25 30 35 40 45 50 55 -200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) M.K.Bhardwaj et al. (1994) M.Ismail (1990) B.P.Singh et al. (1991) M.S.Uddin et al. (2011) Excitation Function of the 123 Sb(α,3n) 124 I Reaction Figure 7. Our cross-section calculations of 123Sb (α,3n)124I reaction compared with experimental data. Nuclear Energy and Technology 11(4): 259–269 265 121I via 121Sb(α,4n) reaction (Fig. 10) The theoretical results for the 121Sb (α,4n) 121I reaction exhibit statistically acceptable agreement with experimental observations. Among all the reactions studied, this channel exhibits the most significant deviation, particularly at higher alpha energies, with a Pearson correlation coefficient of R = 0.74. The reduced agreement is likely due to the complexity of the (α,4n) reaction, which involves the simultaneous emission of four neutrons. Multi-particle emission reactions like this make the model more sensitive to input parameters and nuclear structure, which often leads to bigger differences between calculated and experimental results. Despite these challenges, the COMPLET code still maintains acceptable agreement with experimental datasets reported by Singh and Bhardwaj’ 1991; Bhardwaj 1994; Ismail 1990). The calculated excitation function reaches a peak value of approximately 630 mb at 47 MeV, which is consistent with the general trend of the measured data. 126I via 123Sb (α,n) reaction (Fig. 11) As shown in Fig. 11, the theoretical excitation function for the 123Sb(α,n)126I reaction closely aligns with recent experimental data, particularly those reported by (Ismail 1990; Singh et al. 2006; Uddin et al. 2010; Korkulu et al. 2018). A Pearson correlation coefficient of R = 0.89 confirms the strong agreement. The highest experimental peak, observed by (Uddin et al. 2010), begins around 10 MeV and closely matches the theoretical curve generated by the COMPLET code across the remaining energy range. The excitation function follows a smooth trend. Above 20 MeV, the calculated results and experimental data closely match, confirming the model’s accuracy (Table 2). All analyzed reactions showed strong to highly significant correlation (R > 0.7) between COMPLET predictions and experimental data, confirming 20 30 40 50 -200 0 200 400 600 800 1000 1200 1400 1600 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) K.F.Hassan et al. (2006) M.K.Bhardwaj et al. (1994) M.Ismail (1990) B.P.Singh et al. (1991) Excitation Function of the 121 Sb(α,2n) 123 I Reaction Figure 8. Our cross-section calculations of 121Sb (α,2n)123I reaction compared with experimental data. 35 40 45 50 55 -200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 Energy of alpha (MeV) COMPLET (This Work) M.K.Bhardwaj et al. (1994) M.Ismail (1990) B.P.Singh et al. (1991) Cross section (mb) Excitation Function of the 123 Sb(α,4n) 123 I Reaction Figure 9. Our cross-section calculations of 123Sb (α,4n) 123I reaction compared with experimental data. 35 40 45 50 55 -200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) M.Ismail (1990) B.P.Singh et al. (1991) M.K.Bhardwaj et al. (1994) Excitation Function of the 121 Sb(α,4n) 121 I Reaction Figure 10. Our cross-section calculations of 121Sb (α,4n) 121I reaction compared with experimental data. Figure 11. Our cross-section calculations of 123Sb (α,n)126I reaction compared with experimental data. 10 15 20 25 30 35 40 -50 0 50 100 150 200 250 300 350 400 Cross section (mb) Energy of alpha (MeV) COMPLET (This Work) M.Ismail (1990) M.S.Uddin et al. (2011) Z.Korkulu et al. (2018) B.P.Singh et al. (2006) Excitation Function of the 123Sb(α,n)126I Reaction Mekonen CS et al.: Analysis of excitation functions of alpha particle induced reactions266 the model’s reliability across a wide range of energy-dependent nuclear channels. Statistical analysis shows strong agreement between theoretical predictions and experimental cross-section data for alpha-induced reactions on Cu and Sb isotopes. Most reactions have Pearson correlation coefficients of 0.74 or higher, with several above 0.9, indicating descriptive correlations. This confirms that the model can reliably predict alpha-induced cross-sections for all eleven reactions. The present study provides a comprehensive analysis of alpha particle-induced reactions on 63Cu, 65Cu, 121Sb, and 123Sb isotopes over an extended energy range. The experimentally obtained excitation functions demonstrate clear trends, including enhancements attributable to pre-equilibrium contributions, which are in agreement with the predictions of the COMPLET code. Comparison with previous experimental data indicates both consistency and novel observations, highlighting the reliability of the measurements and the applicability of the theoretical models. These results provide valuable guidance for nuclear data evaluations. They are directly relevant to the production of medically and industrially significant radionuclides. The presented cross sections also provide a foundation for future investigations into complementary reaction channels and higher energy regimes, thereby supporting continued refinement of nuclear reaction modeling. Conclusion This study investigated the excitation functions of eleven alpha-induced nuclear reactions on stable isotopes of copper (63Cu, 65Cu) and antimony (121Sb, 123Sb) using the COMPLET nuclear reaction code across the energy range of 10–80 MeV. Theoretical results were systematically compared with experimental data from the EXFOR database. The COMPLET code, based on the exciton model, was also used to evaluate the impact of exciton number and level density parameters on cross-section predictions. The Pearson correlation coefficients (R-values), ranging from 0.74 to 0.94, indicate strong to excellent agreement between the theoretical calculations and experimental data, confirming the reliability of the COMPLET code in modeling alpha-induced reactions. The analysis particularly focused on medically relevant radionuclides, including 68Ga, 67Ga, 66Ga, 65Zn, 123I, and 124I. These findings suggest that the theoretical calculations can reliably predict reaction cross-section values when experimental data are unavailable. The simulations performed in this study contribute to the evaluation of new data in theoretical works. The study also highlights the model’s sensitivity to input parameters such as level density and optical model potentials, emphasizing the importance of parameter selection in theoretical nuclear modeling. COMPLET demonstrated better performance in reactions involving fewer nucleon emissions, while reactions with higher emission multiplicity revealed the need for careful model choice and tuning. Overall, the findings affirm COMPLET’s utility as a dependable tool for nuclear data evaluation and radionuclide production planning. The results support the enhancement of theoretical nuclear reaction models and contribute to guiding future experimental research, particularly in the field of medical isotope production. 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