Study for observation method of ultra-high energy cosmic ray using acoustic wave of air-shower particles

2015 Fiscal Year Final Research Report

• Project/Area Number: 26610063
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Yokohama National University
• Principal Investigator: KATAYOSE Yusaku 横浜国立大学, 工学(系)研究科(研究院), 准教授 (90323930)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 銀河系外宇宙線 / 空気シャワー / 音響波測定

Outline of Final Research Achievements

For the purpose of measuring extragalactic cosmic ray composition in an energy region larger than 10PeV, a new measurement technique using a sound wave was studied.
High-energy cosmic rays collide with the nucleus of the atmosphere and produce air-shower particles. When the air-shower particles that arrived at the water pool lose their energy underwater, an acoustic wave is produced in the water. The thermo-acoustic mechanism of sound generation by air-shower particles was studied by both a Monte-Carlo simulation and a measurement experiment with a YAG laser.There is a possibility of measuring cosmic rays with an energy greater than 100PeV using the acoustic wave detection method. The results also showed that the acoustic pulse has a bipolar waveform that depends on a primary particle. It was found that separation of a proton event and an iron event is possible using the rise time of an air-shower acoustic wave.

Free Research Field

数物系科学