BremsLib v2.0.8

BremsLib v2.0 is a library of double- and single differential cross sections (DDCS and SDCS) of electron-atom bremsstrahlung. It is a major update of BremsLib v1.0.5, which was published in 2019. BremsLib v2.0 contains the data for 86300 combinations of three physical parameters: atomic number Z, incident electron energy T1, and bremsstrahlung photon energy k. All values of Z from 1 to 100 are represented. The range of values of T1 is from 10 eV to 30 MeV for non-zero k, or from 10 eV to 100 MeV for k = 0. The range of values of k is from 0 to 0.9999*T1. The library data were calculated by the relativistic partial-wave method, except at Z = 1 or Z = 2, T1 - k >= 0.5 MeV, and k > 0 (simultaneously), when the screened Born approximation was used. The target atom is described by Kohn-Sham interaction potential. Radial dependence of proton density inside the nucleus is modeled by the Fermi distribution. The cross sections calculated using the point-nucleus approximation are also included. In comparison with BremsLib v1.0.5, the high-energy endpoint of the incident electron energy range has been increased from 3 MeV to 30 MeV, an additional grid value of k (equal to 0.975*T1) has been inserted at all values of T1, and all the previously-published data have been recalculated, with the point-nucleus approximation replaced by the Fermi distribution of proton density at sufficiently high energies of the incident electron. Although the changes in the values of the previously-published cross sections are insignificant (except at high Z and energies greater than 1 MeV, when the realistic radial distribution of nuclear charge density makes a difference), their uncertainties have been made more reliable. In the soft-photon limit, those uncertainties have been in some cases reduced by several orders of magnitude because of a more efficient calculation method based on the Low soft-photon theorem, which has been applied in the case of zero k at all values of T1 up to 100 MeV. The distribution package of BremsLib v2.0 is in the .ZIP file "BremsLib_v2.0.zip" containing three folders: (a) main data folder "BremsLib_v2.0" with the values of DDCS and SDCS corresponding to 86300 combinations of the physical parameters Z, T1 and k, (b) folder "Interpolate_DCS" with the code and documentation of the program Interpolate_DCS (v1.0.7) for data retrieval and interpolation, (c) folder "Brems" with the code and documentation of the program BREMS (v1.5.8.9), which was used for generation of the library data at non-zero k. The mentioned data and codes are used as supplementary material to the following article: A. Poškus, At. Data Nucl. Data Tables, vol. 166 (2025), 101734, https://doi.org/10.1016/j.adt.2025.101734 In comparison with BremsLib v2.0.7, the only change is correction of a few typos and omissions in the documentation (files BremsLib_v2.0.pdf and Interpolate_DCS.pdf). The data and codes have not been modified.BremsLib v2.0是一款收录电子-原子轫致辐射双微分截面（DDCS）与单微分截面（SDCS）的数据库。它是2019年发布的BremsLib v1.0.5的重大更新版本。BremsLib v2.0包含86300组由三个物理参数组合而成的数据集：原子序数Z、入射电子能量T₁以及轫致辐射光子能量k。其中原子序数Z覆盖了1至100的全部整数取值。入射电子能量T₁的取值范围为：当k≠0时，10 eV至30 MeV；当k=0时，10 eV至100 MeV。光子能量k的取值范围为0至0.9999×T₁。该数据库的截面数据通过相对论分波法计算得到，但存在以下例外情况：当Z=1或Z=2、且同时满足T₁−k≥0.5 MeV与k>0时，采用了屏蔽玻恩近似。靶原子采用科恩-沈吕九相互作用势（Kohn-Sham interaction potential）进行描述，原子核内质子密度的径向分布通过费米分布建模。此外，数据库还包含了采用点核近似计算得到的截面数据。 相较于BremsLib v1.0.5，本次更新将入射电子能量范围的高能上限从3 MeV提升至30 MeV；在所有入射电子能量T₁的取值下，新增了一个k的网格点（取值为0.975×T₁）；所有已发布的原有数据均进行了重新计算，且在入射电子能量足够高的场景下，将点核近似替换为质子密度的费米分布。尽管原有截面数值的变化幅度极小（仅在高原子序数Z且入射能量大于1 MeV的情况下，原子核电荷密度的真实径向分布会产生显著影响），但数据的不确定度评估已更为可靠。在软光子极限下，基于劳软光子定理（Low soft-photon theorem）的高效计算方法被应用于所有T₁≤100 MeV且k=0的场景，部分场景下的不确定度被降低了数个数量级。 BremsLib v2.0的分发包为压缩文件"BremsLib_v2.0.zip"，内含三个文件夹： (a) 主数据文件夹"BremsLib_v2.0"，存储了对应86300组Z、T₁与k参数组合的DDCS与SDCS数据； (b) 文件夹"Interpolate_DCS"，包含数据检索与插值程序Interpolate_DCS（v1.0.7）的代码与文档； (c) 文件夹"Brems"，包含用于生成非零k场景下数据库数据的程序BREMS（v1.5.8.9）的代码与文档。 上述数据与代码作为以下论文的补充材料发布： A. Poškus, At. Data Nucl. Data Tables, vol. 166 (2025), 101734, https://doi.org/10.1016/j.adt.2025.101734 相较于BremsLib v2.0.7，本次更新仅修正了文档（文件BremsLib_v2.0.pdf与Interpolate_DCS.pdf）中的少量拼写错误与遗漏内容，数据与代码未做任何修改。