~（12）C +~（12）C速率不确定性对弱s-过程分量的影响
The effect of 12C + 12C rate uncertainties on the weak s-process component
摘要：
大质量恒星（M > 9太阳质量）对太阳系丰度的弱s过程分量的贡献主要是由于22 Ne中子源，它在氦核燃烧接近尾声时被激活。氦核燃烧后残留的22 Ne在碳燃烧时被重新点燃，引发进一步的s处理，改变同位素分布。这种变化对恒星结构和碳燃烧反应速率很敏感。最近对12 C +12 C反应的研究表明，位于伽莫夫峰内的共振可能存在，导致天体物理S因子的强烈增加，从而导致反应速率的增加。为了研究增加速率的影响，使用日内瓦恒星演化代码（GENEC）生成了25个太阳质量恒星模型，这些恒星模型具有三种不同的碳燃烧速率，在太阳金属丰度下，使用NuGrid多区域后处理网络代码（MPPNP）计算核合成后处理。最强的速率导致碳燃烧发生在一个大的对流核心，而不是一个辐射。这个大的对流核的存在导致与随后的对流碳壳的重叠，显著改变了碳壳的初始组成。此外，增强的速率导致碳壳燃烧事件在恒星演化的早期点燃，在较低的温度下点燃22 Ne源并降低中子密度。
英文摘要：
The contribution by massive stars (M > 9 solar masses) to the weak s-process component of the solar system abundances is primarily due to the 22Ne neutron source, which is activated near the end of helium-core burning. The residual 22Ne left over from helium-core burning is then reignited during carbon burning, initiating further s-processing that modifies the isotopic distribution. This modification is sensitive to the stellar structure and the carbon burning reaction rate. Recent work on the 12C + 12C reaction suggests that resonances located within the Gamow peak may exist, causing a strong increase in the astrophysical S-factor and consequently the reaction rate. To investigate the effect of an increased rate, 25 solar mass stellar models with three different carbon burning rates, at solar metallicity, were generated using the Geneva Stellar Evolution Code (GENEC) with nucleosynthesis post-processing calculated using the NuGrid Multi-zone Post-Processing Network code (MPPNP). The strongest rate caused carbon burning to occur in a large convective core rather than a radiative one. The presence of this large convective core leads to an overlap with the subsequent convective carbon-shell, significantly altering the initial composition of the carbon-shell. In addition, an enhanced rate causes carbon-shell burning episodes to ignite earlier in the evolution of the star, igniting the 22Ne source at lower temperatures and reducing the neutron density.
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