Study of production mechanism of positron and neutrons in lightning and thunderclouds

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05115
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Tsuchiya Harufumi 国立研究開発法人理化学研究所, 仁科加速器研究センター, 客員研究員 (70415230)
• Co-Investigator(Renkei-kenkyūsha): ENOTO TERUAKI 国立研究開発法人理化学研究所, 仁科加速器研究センター, 客員研究員 (20748123) ; YUASA TAKAYUKI 国立研究開発法人理化学研究所, 仁科加速器研究センター, 基礎科学特別研究員 (10609176)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 粒子加速 / 放射線計測 / 雷 / 雷雲 / ガンマ線 / 中性子 / 陽電子 / 光核反応

Outline of Final Research Achievements

How neutrons and positrons are produced in lightning and thunderclouds remains less understood. In order to investigate the production mechanism of neutrons and positrons, we have made radiation observations at the Kashiwazaki-Kariwa nuclear power plant facing the coastal area of the Japan sea upto date.
In association with lightning on 2017 February, our detectors installed at the power plant caught intense gamma-ray signals lasting for 100 ms. In addition, signals derived from neutrons and positrons were also detected. For the first time, this works revealed that neutrons and positrons both originate from photonuclear reactions occurring in lightning.

Free Research Field

宇宙線物理学