Sallam O I, Rammah Y S, Nabil Islam M, El-Seidy Ahmed M A
Glass Lab, Radiation Chemistry Department, National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
Department of Physics, Faculty of Science, Menoufia University, Shebin El-Koom, Menoufia, 32511, Egypt.
Sci Rep. 2024 Oct 18;14(1):24478. doi: 10.1038/s41598-024-73892-w.
Lead borate glass is the best radiation shielding glass when lead is in high concentration. However, it has low transparency after radiation exposure. Radiation decreases transparency due to chemical and physical changes in the glass matrix, such as creating or healing defects in the glass network. The addition of rare earth elements like cerium and dysprosium oxides to lead borate glasses can improve their transparency and durability as radiation shielding barriers. The newly manufactured glasses' optical absorption, structural, and radiation shielding properties were measured. The optical characteristics of the generated samples were examined to determine the effect of the cerium/dysprosium ratio on the structural alterations, specifically in the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Incorporating Ce results in peaks at 195 nm for borate units, 225 nm for Ce, and a broadened peak at 393 nm due to overlapping peaks for Ce and Ce in the UV region. By adding Dy, multiple peaks are observed at 825, 902, 1095, 1275, and 1684 nm, corresponding to the transition from H ground state to F, F, F, F, and H. The samples were also tested before and after exposure to gamma irradiation from a Co source at a dose of 75 kGy to assess their stability against radiation. The energy gap value during irradiation shows decreased non-bridging oxygen. The energy gap difference before and after irradiation for the M4 sample shows higher NBO to BO conversion, reducing radiation damage and improving structural stability. Furthermore, X-ray photoelectron spectroscopy was utilized to get insight into the coordination chemistry of the created glass samples. The half-value layer (HVL), radiation protection efficiency (RPE), neutron removal cross-section (FRNCS), mean free path (MFP), mass attenuation coefficients (MAC), and effective atomic numbers (Z) of the glassy structure were calculated theoretically to assess its radiation shielding qualities. The linear attenuation coefficient order for the prepared samples was M1 > M2 > M3 > M4. The FRNCS values were 0.090, 0.083, 0.081, and 0.079 cm for samples M1, M2, M3, and M4, respectively.
当铅浓度较高时，硼酸铅玻璃是最佳的辐射屏蔽玻璃。然而，在辐射暴露后它的透明度较低。辐射会降低透明度，这是由于玻璃基体中的化学和物理变化，比如在玻璃网络中产生或修复缺陷。向硼酸铅玻璃中添加铈和氧化镝等稀土元素，可以提高其作为辐射屏蔽屏障的透明度和耐久性。对新制造的玻璃的光吸收、结构和辐射屏蔽性能进行了测量。研究了所制备样品的光学特性，以确定铈/镝比例对结构变化的影响，特别是在存在桥氧（BO）和非桥氧（NBO）的情况下。掺入铈会导致硼酸盐单元在195nm处出现峰，铈在225nm处出现峰，并且由于紫外区域中铈和铈的峰重叠，在393nm处出现一个变宽的峰。通过添加镝，在825、902、1095、1275和1684nm处观察到多个峰，对应于从H基态到F、F、F、F和H的跃迁。还对样品在来自钴源的剂量为75kGy的伽马辐射暴露前后进行了测试，以评估它们对辐射的稳定性。辐照期间的能隙值显示非桥氧减少。M4样品辐照前后的能隙差异显示出较高的NBO到BO的转化率，减少了辐射损伤并提高了结构稳定性。此外，利用X射线光电子能谱来深入了解所制备玻璃样品的配位化学。从理论上计算了玻璃结构的半值层（HVL）、辐射防护效率（RPE）、中子去除截面（FRNCS）、平均自由程（MFP）、质量衰减系数（MAC）和有效原子序数（Z），以评估其辐射屏蔽质量。所制备样品的线性衰减系数顺序为M1＞M2＞M3＞M4。样品M1、M2、M3和M4的FRNCS值分别为0.090、0.083、0.081和0.079cm。
