Precision Measurement of Cosmic Ray Chemical Composition by High Resolution Imaging Direct Cherenkov Light

2014 Fiscal Year Final Research Report

• Project/Area Number: 24654061
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: SASAKI MAKOTO 東京大学, 宇宙線研究所, 准教授 (40242094)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 宇宙線核種 / 宇宙線起源 / 銀河内宇宙線 / 宇宙線スペクトル / 超新星 / 宇宙線伝播 / 直接チェレンコフ光 / 宇宙線加速

Outline of Final Research Achievements

The measurement of "Direct Cherenkov" (DC) light, of which intensity is propotional to the charge Z of the primary cosmic ray particle, should be a clear identification of particle species with less ambiguities. In that case, clear discrimination between DC and air shower components is a key. We have developed a very precise imaging device with the angular resolution less than 1 arcmin (i.e. 0.015 deg) for this purpose. We installed it onto a light collector in the Ashra Observatory on Mauna Loa in Hawaii and purformed several investigation observations. The data analysis is on going.

Free Research Field

宇宙素粒子物理学