Japan Geoscience Union Meeting 2018

Presentation information

[EE] Oral

P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM16] Dynamics of Earth's Inner Magnetosphere and Initial Results from Arase

Tue. May 22, 2018 9:00 AM - 10:30 AM 303 (3F International Conference Hall, Makuhari Messe)

convener:Danny Summers(Memorial University of Newfoundland), Yoshizumi Miyoshi(Institute for Space-Earth Environmental Research, Nagoya University), Keisuke Hosokawa(電気通信大学大学院情報理工学研究科, 共同), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University), Chairperson:Summers Danny

10:15 AM - 10:30 AM

[PEM16-24] High-energy electron observation with the HEP instruments onboard Arase

*Takefumi Mitani1, Takeshi Takashima1, Tomoaki Hori2, PARK INCHUN2, Yoshizumi Miyoshi2, Satoshi Kasahara3, Satoshi Kurita2, Mariko Teramoto2, Nana Higashio1, Iku Shinohara1 (1.Japan Aerospace Exploration Agency, 2.Nagoya University, 3.The University of Tokyo)

Keywords:Arase, High-energy electron

The high-energy electron experiments (HEP) onboard the Arase satellite detect 70 keV-2 MeV electrons and generates a three-dimensional velocity distribution of electrons for every period of the spacecraft spin. HEP comprises two types of telescopes, HEP-L and HEP-H, that have different geometrical factors (G-factor) and energy ranges. HEP-L observes 70 keV-1.0 MeV electrons, and its G-factor is about 10−3 cm2 sr for three detector modules, and HEP-H observes 0.7-2.0 MeV, and its G-factor is about 10−2 cm2 sr. To deduce the distribution of incident electrons from the direction and energy detections in orbit, we are developing a detector simulator using the Geant4 toolkit. Especially contamination from high energy particles must be take care of with the simulator. We are working on comparisons between the simulation results and observation.

Since HEP started its normal observations in late March 2017, it has observed several cycles of sudden depletion and recovery of electron fluxes in the outer radiation belt in response to geomagnetic storms. When the geomagnetic activity was low for about a month, the electron fluxes slowly decrease in the outer radiation belt.

We will present calibration status using the simulator and also highlights of the HEP one-year observations.