JpGU-AGU Joint Meeting 2017

Presentation information

[EJ] Poster

P (Space and Planetary Sciences) » P-CG Complex & General

[P-CG24] [EJ] Planetary Magnetosphere, Ionosphere, and Atmosphere

Sun. May 21, 2017 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL7)

[PCG24-P04] Pitch angle scattering due to elastic collisions between magnetospheric keV electrons and neutral H2O molecules originated from Enceladus

*Hiroyasu Tadokoro1, Yuto Katoh2 (1.Musashino University, 2.Tohoku University)

Keywords:Saturn, Enceladus, Pitch angle scattering

The observations of injected plasmas in the inner magnetosphere suggest that these particles do not survive very long time due to the neutral cloud originated from Enceladus [e.g., Paranicas et al., 2007; 2008]. These neutrals in the inner magnetosphere play the dominant role in a loss process of energetic electrons and ions [e.g., Paranicas et al., 2007; Sittler et al., 2008]. However, little has been reported on a quantitative study of the electron loss process due to electron-neutral collisions. In this study, we focus on the elastic collisional loss process with neutrals. Conducting one dimensional test-particle simulation, Tadokoro et al. [2014] examined the time variations of equatorial pitch angle distribution and electrons within loss cone through 1 keV electron pitch angle scattering due to electron-H2O elastic collisions around Enceladus when the electron flux tube passes the region of the dense H2O molecules in the vicinity of Enceladus (~380 sec). The result showed that the electrons of 11.4 % are lost in ~380 sec. Next remaining issue is loss rate of electrons with other energy. In this study, we show a preliminary result of the loss rate of electrons with 500eV-50keV. We also show the comparison of the loss rate between the high H2O density region (in the vicinity of Enceladus) and the low H2O density region (in the Enceladus torus).