AI 中文总结
本文提出Savi-Bhransha图论方法，无需全局界面网格即可高效表征晶体位错环，其在复杂环境中更稳定、速度更快，可用于辐射损伤模拟分析并与实验结果对比。
AI 中文摘要
位错环决定了晶体材料的性能，但当位错环破碎或嵌入致密缺陷碎片中时，从原子级模拟中提取其详细特征十分困难。本文提出Savi-Bhransha，一种图论方法，可直接从局部缺陷位移基序中间隙型和空位型位错环，无需构建全局界面网格。该方法可识别体心立方（BCC）、面心立方（FCC）和密排六方（HCP）晶体的伯格斯矢量族、 habit平面、位错环尺寸、分段刃型/螺型特征，以及边界和体缺陷的数量。我们将其应用于体心立方钨（BCC W）和密排六方锆（HCP Zr）在不同能量下的单次级联模拟，以及体心立方钨（BCC W）和面心立方铁镍铬（FCC FeNiCr）的连续碰撞级联模拟，并以位错提取算法（DXA）为基准进行测试。两种方法的总位错长度仍高度相关，但在DXA返回破碎、重叠开放段的复杂环境中，Savi-Bhransha返回更稳定的位错环级对象，且能更好地分辨混合形态缺陷及其他缺陷（包括空位团）附近的位错。对于BCC W，其中位运行速度提升6.34倍；对于HCP Zr，速度提升8.86倍，峰值内存降低最高达7.77倍。在W的连续级联中，分辨出的边界缺陷浓度介于瞬态光栅光谱测量值之间，且预测的伯格斯矢量分数与室温透射电子显微镜（TEM）结果一致；在FCC FeNiCr中，该方法可分辨Heidenreich-Shockley分解，约91%存活的<110>族间隙团簇具有Shockley对特征。因此，Savi-Bhransha可实现对大型辐射损伤模拟的高效拓扑分辨分析，并直接与实验可测观测量进行比较。
英文摘要
Dislocation loops govern the properties of crystalline materials, but extracting their detailed characteristics from atomistic simulations is difficult when loops are fragmented or embedded in compact defect debris. We present Savi-Bhransha, a graph-theoretic method that reconstructs interstitial and vacancy loops directly from local defect-displacement motifs, without constructing a global interface mesh. The method identifies Burgers-vector family, habit plane, loop size, segment-wise edge/screw character, and boundary and bulk defect populations for BCC, FCC, and HCP crystals. We apply it to single-cascade simulations over a range of energies in BCC W and HCP Zr, and to successive collision cascades in BCC W and FCC FeNiCr. We benchmark the method against the Dislocation Extraction Algorithm (DXA). Total dislocation lengths remain strongly correlated between the two methods, while Savi-Bhransha returns more stable loop-level objects in complex environments where DXA returns fragmented, overlapping open segments. Savi-Bhransha also better resolves mixed-morphology defects and dislocations near other defects, including vacancy clusters. Median runtime speedups are 6.34x for BCC W and 8.86x for HCP Zr, with peak-memory reductions up to 7.77x. In successive W cascades, the resolved boundary-defect concentration brackets transient-grating-spectroscopy measurements and the predicted Burgers-vector fraction agrees with room-temperature TEM. In FCC FeNiCr, the method resolves Heidenreich-Shockley dissociation, with a Shockley-pair signature in about 91% of surviving <110>-family interstitial clusters. Savi-Bhransha therefore enables efficient, topology-resolved analysis of large radiation-damage simulations and direct comparison with experimentally accessible observables.
