Determining the relative production cross-sections of the short-lived (ground) and long- lived (metastable) states of Ta is integral in nuclear physics research. However, direct measurement of these cross-sections is challenging. In this study, we proposed a method for estimating the total flux-weighted average formation cross-section of Ta based on GEANT4 modeling to evaluate the short-lived (ground) and long-lived (metastable) states of Ta. A Ta target was irradiated by a bremsstrahlung photon beam (maximum electron energy: 20 MeV) obtained from the linear electron accelerator LUE-75 at the A.I. Alikhanyan National Science Laboratory (AANL), Armenia. The experiment was performed using the activation technique, and the proposed GEANT4 simulation-based method was employed to evaluate the flux-weighted average formation cross-section of Ta. In addition, the isomeric cross-section ratio for the Ta isomeric pair was calculated. The theoretical results obtained using the TALYS 1.96 and EMPIRE 3.2 codes were consistent with the experimental ones. To the best of the authors’ knowledge, this paper reports the estimated flux-weighted average formation cross-section of Ta and isomer ratio for the Ta isomeric pair, induced by the irradiation of a bremsstrahlung beam with an end-point energy of 20 MeV, for the first time. This study opens new avenues for determining the relative production cross-sections of the ground and metastable states of Ta, which is widely studied as a natural isomeric target in various fields, including nuclear transformation reactions, fission dynamics, etc.

中文翻译：

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光中子反应中 180mTa 形成截面的评估

确定 Ta 的短寿命（基态）和长寿命（亚稳态）态的相对产生截面是核物理研究中不可或缺的一部分。然而，直接测量这些横截面具有挑战性。在本研究中，我们提出了一种基于GEANT4模型估计Ta总通量加权平均地层横截面的方法，以评估Ta的短寿命（基态）和长寿命（亚稳态）状态。轫致辐射光子束（最大电子能量：20 MeV）照射 Ta 靶，该光子束由亚美尼亚 AI Alikhanyan 国家科学实验室 (AANL) 的线性电子加速器 LUE-75 获得。实验采用激活技术进行，并采用所提出的基于GEANT4模拟的方法来评估Ta的通量加权平均地层横截面。此外，还计算了Ta异构体对的异构体横截面比率。使用TALYS 1.96和EMPIRE 3.2代码获得的理论结果与实验结果一致。据作者所知，本文报告了由终点能量为 20 MeV 的轫致辐射束照射引起的 Ta 异构体对的估计通量加权平均形成横截面和 Ta 异构体对的异构体比率，第一次。这项研究为确定 Ta 的基态和亚稳态的相对产生截面开辟了新途径，Ta 作为天然异构体靶标在核转变反应、裂变动力学等各个领域被广泛研究。