利用多离子碎裂数据对用于强子治疗的量子分子动力学模型进行系统参数优化
Systematic Parameter Optimization of Quantum Molecular Dynamics Models for Hadron Therapy Using Multi-Ion Fragmentation Data
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中文总结 AI 辅助
该研究针对强子治疗中量子分子动力学模型参数凭经验选择的问题，通过校准波包宽度、最大演化时间和碰撞参数包络因子三个参数开发优化框架，用多离子碎裂数据优化，提升了模型性能，为核碎裂提供一致描述，可改善相关计算。
中文摘要 AI 辅助
量子分子动力学（QMD）模型广泛用于模拟强子治疗中的核碎裂，但其预测准确性强烈依赖于常凭经验选择的参数。我们通过为具有NS2参数集的相对论平均场模型以及具有SLy4和SkM*参数集的Skyrme模型系统校准三个参数，开发了一个优化的QMD框架：波包宽度L、最大演化时间Tm和碰撞参数包络因子benv。波包宽度由实验电荷半径确定，而Tm和benv被参数化为入射动能和反应系统质量的函数，并使用30 - 400MeV/u的质子和重离子诱导的碎裂数据进行优化。将性能与原始的LiQMD、Binary Cascade和Liege Intranuclear Cascade模型进行比较。优化后的Tm强烈依赖于入射能量但仅微弱依赖于系统质量，表明从动态QMD阶段到统计去激发的转变主要由碰撞能量控制。相比之下，benv表现出模型依赖行为。优化后的参数化改善了与实验碎片产生截面、角分布和能量分布的一致性。优化后的Skyrme模型总体性能最佳，在大多数数据集上优于级联模型。该框架为多个可观测量的核碎裂提供了物理上一致的描述，可能改善强子治疗中次级粒子输运、剂量沉积和线能量转移的计算。
英文摘要
Quantum molecular dynamics (QMD) models are widely used to simulate nuclear fragmentation in hadron therapy, but their predictive accuracy depends strongly on parameters that are often selected empirically. We developed an optimized QMD framework by systematically calibrating three parameters for a relativistic mean-field model with the NS2 parameter set and Skyrme models with the SLy4 and SkM* parameter sets: the wave-packet width L, maximum evolution time Tm, and impact-parameter envelope factor benv. The wave-packet width was determined from experimental charge radii, whereas Tm and benv were parameterized as functions of incident kinetic energy and reaction-system mass and optimized using proton- and heavy-ion-induced fragmentation data over 30-400 MeV/u. Performance was compared with the original LiQMD, Binary Cascade, and Liege Intranuclear Cascade models. The optimized Tm depended strongly on incident energy but only weakly on system mass, indicating that the transition from the dynamical QMD stage to statistical de-excitation is governed mainly by collision energy. In contrast, benv showed model-dependent behavior: NS2 favored larger peripheral-collision contributions for lighter systems at low energies, whereas the Skyrme models showed relatively weak energy and mass dependence. The optimized parameterizations improved agreement with experimental fragment production cross sections, angular distributions, and energy distributions. The optimized Skyrme models achieved the best overall performance and outperformed the cascade models for most datasets. This framework provides a physically consistent description of nuclear fragmentation across multiple observables and may improve calculations of secondary-particle transport, dose deposition, and linear energy transfer in hadron therapy.
