| Exploration on Moon is now a highlighted point in the field of deep space exploration.Research on lunar reflected ions is basic and key for exploration on Moon.In this paper,we firstly introduced space environment near moon,lunar surface magnetic anomalies and lunar surface electric field.By analyzing ion data detected by SWID(solar wind ion detector)on board Chang'E-2,we present that lunar reflected ions are widely spread in space environment near moon,and their movement is controlled by interplanetary magnetic field and convection electric field.Based on Chang'E-2 data,using test particle simulation,we traced back the trajectory of lunar reflected ions,showing that lunar surface is reflecting solar wind ions,by the efficiency of reflection is lower than by magnetic anomalies.When reflected by lunar surface,the ions can go upward with rather large kenetic energy.Ions are first scattered by lunar regolith,then accelerated upward by lunar surface electric field.And the positive lunar surface potential in solar wind is about 45V~75V.Besides protons,helium ions also can be reflected on lunar surface.Further more,in this paper we researched the character of solar wind ions reflected on lunar surface,analyzed lunar surface electric field and its influence on lunar surface reflected ions.In this paper,we analyzed distribution of ion reflection angles under different lunar surface potentials,further calculated lunar surface potential.Conclusion of this paper is: Lunar regolith is reflecting solar wind ions,but efficiency is 2~3 order of magnitude lower than reflection of lunar magnetic anomalies.After being scattered,ions are accelerated by lunar surface potential upward.Lunar regolith is also reflecting helium ions.In this paper,we researched character of ions reflected on lunar surface,that would be helpful for latter simulation works on lunar reflected ions,especially for building more advanced models. |
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