Acceleration of single‐ and multi‐charged oxygen ions in the perturbed Earth's magnetotail is investigated as the possible source of energetic heavy ions in the ring current. The numerical model is developed that allows evaluating the acceleration of oxygen ions O⁺‐O⁺⁸ in two possible scenarios of characteristic perturbations: (A) passage of multiple dipolarization fronts in the magnetotail; (B) passage of fronts followed by electromagnetic turbulence. It is shown that acceleration processes depend on particle charges as well as characteristic time scales of induced electric field variations. Maximum energies gained by oxygen ions correlate with values of their charges. Our simulations show that all kinds of single‐ and multiply charged heavy particles can be efficiently accelerated during multiple dipolarizations processes of the type (A) from initial energies 12 keV to maximum energies about several MeV. The gain of energies of heavy ions under the (B) scenario of magnetospheric perturbations is about 10% higher than in (A) scenario. The shapes of obtained in the model energy spectra were shown to be in agreement with experimental spectra in the range of L‐shells corresponding to ring/radiation belts. Therefore we conclude that the Earth's magnetotail can play the role of the depot where oxygen ions of both ionospheric and solar wind origin can be effectively accelerated during magnetic substorms to energies about several MeV and then populate the ring current and radiation belts of the Earth.

中文翻译：

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地球磁尾巴是加速单电荷和多电荷氧离子的储藏库，补充了辐射带

研究了被扰动地球磁尾中单电荷和多电荷氧离子的加速，作为环流中高能重离子的可能来源。建立了数值模型，可以评估氧离子O ⁺ -O ⁺⁸的加速度在两种可能的特征扰动情况下：（A）磁尾中多个双极化前沿通过；（B）前面通过，随后是电磁湍流。结果表明，加速过程取决于粒子电荷以及感应电场变化的特征时间尺度。氧离子获得的最大能量与其电荷值相关。我们的模拟表明，在类型（A）的多个双极化过程中，从初始能量12 keV到最大能量约几MeV，各种类型的单电荷和多电荷重粒子都可以有效地加速。在（B）磁层扰动情况下，重离子的能量增益比（A）方案高约10％。在模型能谱中获得的形状显示出与对应于环/辐射带的L壳范围内的实验光谱一致。因此，我们得出的结论是，地球的磁尾可以起到该仓库的作用，在电磁亚暴期间，电离层和太阳风的氧离子都可以有效地加速到大约几兆电子伏特的能量，然后填充地球的环流和辐射带。