Loss of energetic ions comprising the ring current populations of Jupiter's middle and inner magnetosphere
Loss of energetic ions comprising the ring current populations of Jupiter's middle and inner magnetosphere
复制标题
木星中磁层和内磁层环电流群中高能离子的损失
DOI：
10.1029/2022ja030293
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Sulaiman A. H.
中科院分区：
文献类型：
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作者：
Mauk B. H.;Allegrini F.;Bagenal F.;Bolton S. J.;Clark G.;Connerney J. E. P.;Gershman D. J.;Haggerty D. K.;Hue V.;Imai M.;Kollmann P.;Kurth W. S.;Nenon Q.;Paranicas C. P.;Rymer A. M.;Smith H. T.;Sulaiman A. H.
朱诺号使命的低空极地轨道允许木星高能粒子探测器仪器观察并分辨高能离子的损失锥，包括木星环电流离子的低空延伸。对于从木卫三轨道内部到远远超出木卫三轨道的区域，高能离子（>50 keV的H+和>130 keV的氧和硫离子）强烈散射到损失锥中，并在“强扩散极限”下基本上一直丢失到磁层。通过反对磁曲率散射，我们得出结论，原因是波，这可能与之前在赤道地区记录的阿尔夫文变化有关。在木卫二和木卫一的轨道附近，散射通常很弱或不存在，除了共转等离子体下游的区域。对于木卫一，我们有时会观察到在下游大约60°范围内的中等但不饱和的散射。值得注意的是，在木卫一位置的上游，散射很弱或不存在，这种不对称性在以前的一些波观测中得到了回应。对木卫一轨道附近的总散射损失（经度平均）的初步计算得出，H+的损失率约为强扩散极限的4%-5%，重离子（O + S）的损失率约为5%-7%。我们的结论是，在木卫一的轨道附近，电荷交换损失可能主导重离子和较低能量的H+离子（大约<200 keV）的散射损失。
The low‐altitude, polar orbit of the Juno mission allows the Jupiter Energetic Particle Detector Instrument to view into, and resolve, the loss cone of energetic ions comprising the low‐altitude extension of Jupiter's ring current ions. For regions mapping from just inside Ganymede's orbit to well beyond Ganymede's orbit, energetic ions (>50 keV H+and >130 keV Oxygen and Sulfur ions) are strongly scattered into the loss cone and lost to the magnetosphere at the “strong diffusion limit” at essentially all times. We conclude, by arguing against magnetic curvature scattering, that the cause is waves, perhaps associated with Alfvénic variations previously documented in this equatorial region. Scattering is generally weak or nonexistent near the orbits of the moons Europa and Io, except for the regions just downstream of the corotating plasmas. For Io, we sometimes observe moderate, but not saturated, scattering within roughly 60° downstream. Significantly, scattering is weak or nonexistent just upstream of Io's position, an asymmetry echoed in some previous wave observations. A preliminary accounting of the total (longitude‐averaged) scattering losses near Io's orbit yields loss rates of order 4%–5% of the strong diffusion limit for H+and 5%–7% for heavy ions (O + S). We conclude that near Io's orbit, charge exchange losses likely dominate over scattering losses for heavy ions and for the lower energy H+ions (roughly <200 keV).