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Cosmic rays, originating from celestial phenomena such as stars, supernovae, and other astrophysical sources, are composed of high-energy particles that enter Earth’ s atmosphere. Upon interaction with atmospheric nuclei, these primary cosmic rays generate an array of secondary particles, with muons constituting the dominant component at ground level. Muons, due to their relative abundance, stability, and well-characterized energy loss mechanisms, serve as critical probes for investigating the fundamental properties of cosmic rays. Studies of muon energy distribution, diurnal anisotropy, and their modulation by solar activity provide essential insights into the mechanisms of particle acceleration in cosmic ray sources and the influence of solar and atmospheric effects.
This study aims to characterize the counting spectrum and anisotropic properties of cosmic ray muons using a plastic scintillator detector system. The experiment was conducted over a three-month period, from December 2023 to February 2024, leveraging long-bar plastic scintillator detectors equipped with dual-end photomultiplier tubes (PMTs) and a high-resolution digital data acquisition system. A dual-end coincidence measurement technique was implemented to enhance the signal-to-noise ratio by suppressing thermal noise and other background interferences. Comprehensive calibration of the detection system was performed using standard gamma-ray sources, including 137Cs, 60Co, and 40K, ensuring precise energy scaling and reliable performance.
The observed energy spectrum of cosmic ray muons showed excellent agreement with theoretical predictions, accounting for the energy losses incurred as muons traverse the detector. Diurnal variations in muon count rates revealed a pronounced pattern, with a systematic reduction observed between 8:00 AM and 1:00 PM. This phenomenon is attributed to solar shielding effects, wherein enhanced solar activity during daytime hours modulates the flux of galactic cosmic rays reaching Earth’ s surface. To account for atmospheric influences, meteorological corrections were applied using temperature and pressure adjustment functions derived from regression analysis. These corrections revealed that atmospheric pressure and temperature are significant factors influencing muon count rates, with clear linear relationships observed.
The study further corroborated these findings through cross-comparisons with data from the Yangbajing Cosmic Ray Observatory. Minor discrepancies, primarily in low-energy muon count rates, were attributed to variations in detector sensitivities and local atmospheric conditions. These observations underscore the robustness of the plastic scintillator detector system for capturing detailed muon spectra and anisotropic patterns.
In conclusion, this research establishes a reliable experimental framework for analyzing cosmic ray muons and their modulation by solar and atmospheric phenomena. The results contribute to a deeper understanding of cosmic ray anisotropy and the interplay between astrophysical and geophysical processes. Furthermore, the findings provide valuable insights for optimizing detection technologies and enhancing the accuracy of cosmic ray studies.-
Keywords:
- cosmic rays /
- muons /
- anisotropy /
- plastic scintillator /
- solar modulation
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[1] Liu J,Cao Z 2024 Physics 53237(in Chinese)[刘佳，曹臻2024物理53237]
[2] Li C,Yang R Z,Cao Z 2024 Chin. Sci. Bull. 692698(in Chinese)[李骢，杨睿智，曹臻2024科学通报692698]
[3] Axi Kugu,Zhou X X,Zhang Y F 2024 Acta Phys. Sin. 73129201(in Chinese)[阿西克古， 周勋秀，张云峰2024物理学报73129201]
[4] Compton A H,Getting I A 1935 Physical Review 47817
[5] Song X J,Luo X 2022 Proc. of the Joint Annual Meeting of Chinese Earth Sciences - 1(in Chinese)[宋小健，罗熙2022年中国地球科学联合学术年会论文集— 1]
[6] Tong F,Jia H Y,Zhou X X, et al. 2015 Nucl. Phys. Rev. 32286(in Chinese)[仝帆，贾焕玉，周勋秀，等2015原子核物理评论32286]
[7] Liu J,Zhou D W 2007 J. Zhengzhou Univ. (Nat. Sci. Ed.) 0175(in Chinese)[刘王君，周德文 2007郑州大学学报(理学版) 0175]
[8] Liu J,Jia H Y,Huang Q 2004 Nucl. Phys. Rev. 0138(in Chinese)[刘王君，贾焕玉，黄庆2004原子核物理评论0138]
[9] Jia H Y,Cao Z,Zhang H M 1994 High Energy Phys. Nucl. Phys. 09788(in Chinese)[贾焕玉，曹臻，张慧敏1994高能物理与核物理09788]
[10] Liu Y,Niu H R,Li B B,et al. 2023 Acta Phys. Sin. 72140202(in Chinese)[刘烨，牛赫然， 李兵兵，等2023物理学报72140202]
[11] Aemnomori M et al. 2005 The Asrophysical Journal 626 L29
[12] Wang Q Q,Zhang X,Tian L C,et al. 2023 J.Nucl.Tech. 4617(in Chinese)[王启奇，张湘， 田立朝，等2023核技术4617]
[13] Liu X M,Song X J,Geng Z K,et al. 2024 Chinese J. Geophys. 671299(in Chinese)[刘新铭，宋小健，耿泽坤，等2024地球物理学报671299]
[14] Xiao Z Y,Wang Z C,Huang X,et al. 2022 Guangxi Phys. 438 (in Chinese)[肖政耀，王梓丞，黄新，等2022广西物理438]
[15] He W J,Li B 2024 College Phys. 4360(in Chinese)[何韦杰，李波2024大学物理4360]
[16] Yin J,Zhang Y P,Ni F F,et al. 2017 Nuclear Electronics Detection Technology 37929(in Chinese)[尹俊，张亚鹏，倪发福，等2017核电子学与探测技术37929]
[17] Pi B S, Wei Z Y, Wang Z, et al. 2017 J.Nucl.Tech. 4061(in Chinese)[皮本松, 魏志勇, 王振, 等.2017核技术4061]
[18] Han J X, Ye Y L, Lou J L, et al. 2023 Commun Phys 6220
[19] Geng P, Duan L M, Ma Peng, et al. 2010 Nuclear Physics Review 27450(in Chinese)[耿朋, 段利敏, 马朋, 等. 2010原子核物理评论27450]
[20] Hao J X,Guo G,Sun B H 2024 College Phys. 4355(in Chinese)[郝佳欣，郭戈，孙保华2024大学物理4355]
[21] Chang L, Liu Y D, Du L, et al. 2015 J.Nucl.Tech. 3846(in Chinese)[常乐, 刘应都, 杜龙, 等2015核技术3846]
[22] Zhang S Y L T, Chen Z Q, Han Rui, et al. 2013 Chinese Physics C 3771
[23] Tang Q Y, Lu H, Le G M, et al. 2004 Chinese Journal of Space Science 24219(in Chinese)[唐云秋, 卢红, 乐贵明, 等. 2004空间科学学报24219]
[24] Xu C L,Wang Y,Qin G,et al. 2023 Research in Astronomy and Astrophysics 23025010
[25] Adamson P et al. 2010 Phys. Rev. D 81012001
[26] Dorman L I 1974 in Cosmic Rays, Variation and Space Exploration. North-Holland.
[27] Erhart A,Wagner V,Wex A,et al. 2024 The European Physical Journal C 841
[28] Zhou X X, Wang X J, Huang D H, et al. 2015 Acta Phys. Sin. 64149202(in Chinese)[周勋秀, 王新建, 黄代绘, 等2015物理学报64149202]
[29] Zhang J L, Tan Y H, Wang H, et al. 2010 Nucl. Instrum. Methods Phys. Res. A 6231030
[30] Institute of High Energy Physics (ihep.ac.cn) http://ybjnm.ihep.ac.cn/.
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