论文标题
电子strahl对内层中倾斜的快速磁通/惠斯勒不稳定性的稳定性
The Stability of the Electron Strahl against the Oblique Fast-magnetosonic/Whistler Instability in the Inner Heliosphere
论文作者
论文摘要
我们根据地中心距离分析了太阳风中电子strahl的微动稳定性。在文献中，斜快速磁体/惠斯勒（FM/W）的不稳定性已成为将电子strahl有效散射到电子晕圈中的关键候选机制。使用来自Parker太阳能探针（PSP）和Helios的数据，我们将测得的Strahl特性与低和高$β_ {\ $β_ {\ parool c} $制度中的斜FM/W不稳定性的分析阈值进行了比较，其中$β_ {\ parallel C} $是核心平行压力的比率。我们的PSP和Helios数据表明，对于内部地球内的倾斜FM/W的不稳定性，电子strahl平均是稳定的。我们的分析表明，不稳定（如果有的话）只能在短时间内和短时间内受到激发。我们讨论了我们的分析的警告以及在太阳风中观察到的电子strahl散射的潜在替代解释。此外，我们建议将来对单个分布的稳定性进行数值评估，以解释不稳定性阈值的分析表达式有效性的任何不确定性。
We analyze the micro-kinetic stability of the electron strahl in the solar wind depending on heliocentric distance. The oblique fast-magnetosonic/whistler (FM/W) instability has emerged in the literature as a key candidate mechanism for the effective scattering of the electron strahl into the electron halo population. Using data from Parker Solar Probe (PSP) and Helios, we compare the measured strahl properties with the analytical thresholds for the oblique FM/W instability in the low- and high-$β_{\parallel c}$ regimes, where $β_{\parallel c}$ is the ratio of the core parallel thermal pressure to the magnetic pressure. Our PSP and Helios data show that the electron strahl is on average stable against the oblique FM/W instability in the inner heliosphere. Our analysis suggests that the instability, if at all, can only be excited sporadically and on short timescales. We discuss the caveats of our analysis and potential alternative explanations for the observed scattering of the electron strahl in the solar wind. Furthermore, we recommend the numerical evaluation of the stability of individual distributions in the future to account for any uncertainties in the validity of the analytical expressions for the instability thresholds.
