Grain‐scale supercharging and breakdown on airless regoliths
Grain‐scale supercharging and breakdown on airless regoliths
复制标题
无空气风化层上的颗粒级增压和分解
DOI：
10.1002/2016je005049
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
K. Hibbitts
中科院分区：
文献类型：
--
作者：
M. Zimmerman;W. Farrell;C. Hartzell;X. Wang;M. Horányi;D. Hurley;K. Hibbitts
太阳风和发射的光电子与无空气物体的相互作用已经得到了广泛的研究。然而，带电粒子如何与风化层相互作用的细节在一个单一的颗粒的规模仍然在很大程度上没有特征。最近的努力集中在确定总的表面电荷下的光电发射和太阳风轰击和相关的电场和电位。在这项工作中，理论和模拟被用来表明，晶粒-晶粒电荷差异可以超过几个数量级的经典鞘层预测，有时达到介电击穿水平。温度依赖性电导率通过允许电流通过单个颗粒泄漏来对抗增压;内部传导和表面充电之间的平衡控制着最大可能的颗粒间电场。了解风化层颗粒充电，导电平衡和介电击穿的细节，将改善未来的空间风化和尘埃悬浮在无空气的机构的数值研究。
Interactions of the solar wind and emitted photoelectrons with airless bodies have been studied extensively. However, the details of how charged particles interact with the regolith at the scale of a single grain have remained largely uncharacterized. Recent efforts have focused upon determining total surface charge under photoemission and solar wind bombardment and the associated electric field and potential. In this work, theory and simulations are used to show that grain‐grain charge differences can exceed classical sheath predictions by several orders of magnitude, sometimes reaching dielectric breakdown levels. Temperature‐dependent electrical conductivity works against supercharging by allowing current to leak through individual grains; the balance between internal conduction and surface charging controls the maximum possible grain‐to‐grain electric field. Understanding the finer details of regolith grain charging, conductive equilibrium, and dielectric breakdown will improve future numerical studies of space weathering and dust levitation on airless bodies.