Study of a thundercloud gamma-ray production model via multiple detectors

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740183
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: TSUCHIYA Harufumi 独立行政法人理化学研究所, 仁科加速器研究センター, 客員研究員 (70415230)
• Research Collaborator: ENOTO Teruaki 独立行政法人理化学研究所, 仁科加速器研究センター, 訪問研究員 (20748123) ; UMEMOTO Daigo 東京大学, 大学院理学系研究科, D2
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 粒子加速 / 雷 / 雷雲 / ガンマ線

Outline of Final Research Achievements

Gamma rays derived from winter thunderstorms have been observed at the coastal area of the Japan Sea. Gamma-Ray Observations of Winter Thunderclouds (GROWTH) experiment has successfully operated gamma-ray measurement at the Kashiwazaki-Kariwa nuclear power plant, revealing that lightning and thunderclouds can accelerate electrons to 10 MeV or higher. The present study installed a new detector consisting of BGO scintillators, increased the number of gamma-ray events to be detected. In addition, GROWTH for the first time observed 511 keV annihilation lines lasting around 60 s, implying that thunderclouds may produce a large flux of positrons.

Free Research Field

数物系科学