Solar modulation model considering the nonlinear diffusion process and its generalization

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K03956
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Ibaraki National College of Technology
• Principal Investigator: Miyake Shoko 茨城工業高等専門学校, 国際創造工学科, 准教授 (00613027)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 銀河宇宙線 / 太陽風 / 磁気乱流 / シミュレーション

Outline of Final Research Achievements

A precise solar modulation model that takes into account nonlinear diffusion processes was constructed, and by comparing it with fluxes of cosmic ray protons and electrons observed by BESS, PAMELA, AMS-02, and CALET, the driving mechanism of magnetic turbulence in the heliosphere and the local interstellar space energy spectrum in the GeV region were estimated. In addition, analysis of low-energy protons and electrons by CALET progressed, and theoretical consideration was achieved using the latest observation results. We also created a demo site to make general-purpose data on cosmic ray energy spectra available. As soon as the results of this research are reported as a paper, we will open these data by using the data public site.

Free Research Field

宇宙線物理学

Academic Significance and Societal Importance of the Research Achievements

本研究により、太陽変調モデルを用いて太陽圏内における磁気乱流の駆動メカニズムを逆に探る新しい手法を確立できた。またGeV領域のLISの検証は、近年発見されている様々な宇宙線核種の数十GeV領域におけるエネルギースペクトル冪指数の変化に関連する可能性もあり、今後の進展が期待される。その他宇宙線エネルギースペクトルの汎用化と汎用データの公開は、宇宙線を専門としない関連学術研究や実用科学に寄与できると期待される。