1999 Fiscal Year Final Research Report Summary
A Study of Chaos in Large Area Air Showers
| Project/Area Number |
09440111
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
素粒子・核・宇宙線
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| Research Institution | Kinki University |
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Principal Investigator |
KONISHI Takeharu Dept Physics, Kinki University, Assist Professor, 理工学部, 助教授 (00088501)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Tamotsu Osaka City Univ, Dept Physics, Professor, 理学部, 教授 (20047137)
OHARA Soji Nara Univ Ind, Fac Economy, Professor, 経済学部, 教授 (60194271)
TSUJI Katsufumi Dept Physics, Kinki University, Assist Professor, 理工学部, 助教授 (30088439)
YAMAMOTO Isao Okayama Univ, Sci, Dept Engineering, Professor, 工学部, 教授 (50090220)
WADA Tomonori Okayama Univ, Dept Physics, Assist Professor, 理学部, 助教授 (10033200)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Cosmic Ray / Air Shower / Chaos / Fractal Dimension |
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| Research Abstract |
We found a chaotic character in the time series of the arrival time difference on the cosmic ray air-shower events. We have organized the Large Area Air Showers observation network (LAAS) which consists of the eight Universities in Japan. Each member in our group can utilize the all data in the data server in Kinki University via internet. As for the chaotic analysis, we are convinced the existence of chaotic cosmic ray. Because another group showed the chaotic character in their data that the event rate is about 10 times higher than our event rate and we confirmed our data has a chaotic character by the maximum Lyapunov index analysis. Further more, we can explain the difference between the chaotic cosmic ray and a chaotic data series made by a random data sample.
1. We investigated the detail of the data series before and after the chaotic cosmic ray data series. There is a chaotic character in them (continuous chaos) and periodicity about 23 hours.
2. The average arrival direction in
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the chaotic data series concentrates the two directions (right ascension 4±1 and 19±1 hour).
Since there is an advantage of a large area observation system, we tried to find the coincidence event observed at two or more observation points. The results are,
3. The selection criteria of the same direction event analysis are observed at least three points, time difference within 64 sec, arrival direction difference within 7 degree, and on the direction of Mkn501. The times of the event increase in this analysis agree with the time of the three maximum flux points at HEGRA observation.
4. In the preliminary results, we have two coincidence events, coincide at Okayama University of science - Kinki University and Hirosaki University - Kinki University, with the criteria of the time difference within 150μsec, the direction difference within 7 degree. The arrival directions of these events are near our Galactic plane.
Since the arrival direction accuracy of air shower event in LAAS observation system is about ±5 degree, we need to improve the accuracy of the direction measurement. Using the direction measurement of the muon in the air shower, our small air shower array will be able to improve the accuracy of the direction measurement. Less
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