论文标题
在地球球中太阳风等离子体的径向谱图
Radial profile of the polytropic index of solar wind plasma in the heliosphere
论文作者
论文摘要
我们结合了质子血浆中质子血浆多粒子指数的不同测量值：i）内层内的近绝热指数〜1AU，ii）外层外层中的亚绝热指数〜20-40AU，iii）近地壳中的Heliosh近零指数。这些观察结果是通过在地球层的整个径向范围内的单个理论模型统一的。相应的拟合揭示了随着HeliePentric距离的增加，多trapic指数的下降趋势R。我们预计随着R的增加，（i）Debye的长度和平均无路径会减少； （ii）Landau阻尼的有效性较低，因此将波能量较少转移到颗粒； （iii）碰撞程度增加，表明内heliosheath中的质子血浆可能是无碰撞的。
We combine different measurements of the polytropic index of the proton plasma in the heliosphere: i) near-adiabatic index in the inner heliosphere ~1AU, ii) subadiabatic indices in the outer heliosphere ~20-40AU, and iii) near-zero indices in the inner heliosheath. These observations are unified by a single theoretical model of the polytropic index throughout its radial extent in the heliosphere; the corresponding fitting reveals the decreasing trend of the polytropic index with increasing heliocentric distance R. We anticipate that with increasing R, (i) the Debye length and mean-free-path decreases; (ii) the Landau damping is less effective, transferring thus less wave energy to particles; and (iii) the collisionality degree increases, indicating that the proton plasma in the inner heliosheath might be collisionless.
