Fermi acceleration of electrons driven by electric fields coupled to curvature drifts during dipolarization
學年 110
學期 2
發表日期 2022-06-07
作品名稱 Fermi acceleration of electrons driven by electric fields coupled to curvature drifts during dipolarization
作品名稱（其他語言）
著者 Kaiti Wang
作品所屬單位
出版者
會議名稱 2022臺灣地球科學聯合學術研討會
會議地點 台北市
摘要 The pitch angle distributions (PADs) of electrons have shown variations due to the changes in field configurations during dipolarization via satellite observations at Earth’s tailside. A specific variation of energy-dependent pattern for the associated field-aligned anisotropies η was also often found from tens of eV to hundreds of eV or from hundreds of eV to thousands of eV during dipolarization by measurements of the instrument ESA (ElectroStatic Analyzer) for < 30keV electrons onboard of THEMIS Mission. In the beginning of dipolarization, a distinct peak of η occurred at a lower energy level; during dipolarization, a peak with smaller value occurred at a higher energy level. Two representative events at 10 Earth radii will be presented. One event showed an increase in differential energy fluxes above ~ 2keV while the other event showed a decrease in these fluxes above a similar energy level. Fermi acceleration of electrons driven by electric fields coupled to curvature drifts is examined by adopting the values of observed electric fields and magnetic fields. Interestingly, deceleration of electrons is found possible to occur through inputting the real observed values of electric/magnetic fields, though this mechanism was used to theoretically explain electrons accelerated to high energies at the presence of a dawn-to-dusk electric field. Therefore, this Fermi acceleration/deceleration is found to yield larger η at higher energy levels closer to observed range as well as produce the observed increase/decrease in changes of differential energy flux above ~ 2keV. This can be considered as the scientific benefit from observations besides theoretical works.
關鍵字 Fermi acceleration;electric fields;curvature drifts;dipolarization;electrons
語言 en
收錄於
會議性質 國內
校內研討會地點 無
研討會時間 20220607~20220610
通訊作者 Kaiti Wang
國別 TWN
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相關連結

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/122771 )