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Methods for Detecting High Energy Photons in Primary Cosmic Rays

Journal Article · · Progress of Theoretical Physics (Kyoto)
DOI:https://doi.org/10.1143/PTP.26.541· OSTI ID:4818786
Detection of the high energy photons in primary cosmic rays provides useful data for the study of the origin of cosmic rays, because they move in straight lines and bring information on the directions of their sources. Two methods are described to detect such photons through the secondary particles produced by them in air. A part of photons can produce inesons capable of reaching sea level through photonuclear interactions with air nuclei, although the majority are absorbed in the atmosphere by producing electron pairs 1010 to 1011ev. These mesons do not suffer considerable scattering from the original direction of - photons, and higher intensities of mesons in a small solid angle containing the direction of the source can be detected in comparison with the average intensity. The lower limit of the photon flux detectable by this metbod is about 4.10-6 cm- sec-i for photons of 200 Bev. For photons near 1012 ev, it is possible to detect cascade showers initiated when observations are made at mountain altitude. Discussions are given on the detection efficiency of these showers by the special arrangement of shower detectors. The minimum detectable flux of photons of 1012 ev by this arrangement is about 2.10-7 cm- sec .
Research Organization:
Nagoya Univ., Japan
Sponsoring Organization:
USDOE
NSA Number:
NSA-16-008091
OSTI ID:
4818786
Journal Information:
Progress of Theoretical Physics (Kyoto), Journal Name: Progress of Theoretical Physics (Kyoto) Journal Issue: 4 Vol. 26; ISSN 0033-068X
Country of Publication:
Country unknown/Code not available
Language:
English