Yunnan Univ, Inst Cosm Ray Res, Kunming 650091, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
; City Univ Hong Kong, Hong Kong, Hong Kong, Peoples R China
; Hong Kong Inst, Hong Kong, Hong Kong, Peoples R China
With the extensive air shower (EAS) array at Mt. Liang Wang (735 g.cm(2), 245degreesN, 102.9degrees E, Kunming China) it is able to measure the muon density spectrum at a fixed distance from the core of EAS in the knee region. The spectra at two different fixed core distances (25m less than or equal to core distance < 30m,30mless than or equal tocore distance < 35m) were obtained from 4.4 x 10(4) events collected in 1994 with criteria 5 x 10(4) less than or equal to size less than or equal to 1.6 x 10(7) and 10degrees less than or equal to theta less than or equal to 30degrees that show obvious kinks. Monte Carlo simulations for the EAS development and detection with same selection criteria in the array triggering and the analysis procedure have been performed in order to relate the local muon densities to primary energy. As a result, we have deduced that the average position of the knee (E-knee) is at about 1.7 x 10(15) eV and the average difference of the slopes of the primary energy spectrum before and after the knee (Deltagamma) is about 0.43. This work corroborates the first result (Ek(nee) = 5PeV, Deltagamma = 0. 3) reported by KASCADE. It authenticates reliably the existence of the knee at the primary energy spectrum by another composition of EAS - muon composition (more direct than electron composition). Based on the results obtained by two experiments, the difference of slopes of cosmic ray primary energy spectrum before and after the knee is close to 0.4 that is accepted widely,while the energy of the knee is different from the accepted 3PeV.
Liu, J,Geng, QX,Yang, HT,et al. Study of EAS local muon density spectrum and the knee in the energy spectrum of primary cosmic rays[J]. HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION,2003,27(2):109-112.
Liu, J.,Geng, QX.,Yang, HT.,Liu, CQ.,Zhang, P.,...&朱清棋.(2003).Study of EAS local muon density spectrum and the knee in the energy spectrum of primary cosmic rays.HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION,27(2),109-112.
Liu, J,et al."Study of EAS local muon density spectrum and the knee in the energy spectrum of primary cosmic rays".HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION 27.2(2003):109-112.