Total flux of Cosmic Rays around knee region using Tibet Air Shower Array

我们分析了西藏阵列获得的实验数据，得到了3*10^<14>和2*10^<16>eV能量范围内的一次宇宙射线能谱。得到的整个初级能谱不像单一的幂律，在E_b=10^<15.25>eV附近的能量处，斜率逐渐变陡。光谱可以表示为J(E_o)=1.5*10^<-20>(E_o/10^<14.75>eV)^<-2.60<正负>0.04>(m^<-2>sec^<-1>sr^<-1>eV^<-1>)atE_o<10^<14.75>eVand=1.2*10^<-23>(E_o/10^<15.85>eV)^<-3.00<正负>0.05>(m^<-2>sec^<-1>sr^<-1>eV^<-1>)atE_o>10^<15.85>eV)，该值在10^<14.75>和10^<15.85>eV之间逐渐变化，取J(E_o)=6.7*10^<-22>(m^<-2>sec^<-1>sr^<-1>eV^<-1>)atE_o=10^<15.25>eVOur光谱平滑地与Grigorov等（1971）和JACEE的直接测量相连接低能量区域的协作（Burnett et al.1993）。在10^<15> eV附近的通量值比Akeno数据高（Nagano et al.1984），而能量在10^<16>附近的通量值比他们的数据低约10%。光谱的弯曲不像秋野那样突然，其能量（E_b）也比它们低。它们在能量约为10^<15>的较低通量可归因于秋野高度的空气阵雨的探测效率非常低。我们在膝盖周围获得的光谱几乎与主要质量成分无关，将被评为最标准的。在较低能量处光谱的逐渐变陡可能有利于在信噪比处的激波加速度，这表明随着能量的增加，各种宇宙射线核的相对丰度发生了相当大的变化，但要证实这一点，需要更多关于膝盖周围能量处主要质量组成的直接信息。

We analyzed the experimental data obtained with Tibet array and obtained the energy spectrum of the primary cosmic rays in the energy range between 3*10^<14>and2*10^<16>eV.The overall primary energy spectrum obtained does not resemble a single power law and shows a gradual steepening of the slope at energies around E_b=10^<15.25>eV.The spectrum can be expressed asJ(E_o)=1.5*10^<-20>(E_o/10^<14.75>eV)^<-2.60<plus-minus>0.04>(m^<-2>sec^<-1>sr^<-1>eV^<-1>)atE_o<10^<14.75>eVand=1.2*10^<-23>(E_o/10^<15.85>eV)^<-3.00<plus-minus>0.05>(m^<-2>sec^<-1>sr^<-1>eV^<-1>)atE_o>10^<15.85>eV,while this changes gradually between 10^<14.75>and 10^<15.85>eV and takes the value J(E_o)=6.7*10^<-22>(m^<-2>sec^<-1>sr^<-1>eV^<-1>)atE_o=10^<15.25>eVOur spectrum to be smoothly connected to the direct measurements by Grigorov et al.(1971) and JACEE Collaboration (Burnett et al.1993) at the lower energy region. The flux values around 10^<15> eV are higher than the Akeno data (Nagano et al.1984), while those at energies around 10^<16> are about 10 % lower than theirs. The bending of the spectrum is not as abrupt as the Akeno and its energy (E_b) is also lower than theirs. Their lower flux at energies around 10^<15> could be attributed to very low detection effciencies of air showers at the Akeno altitude.Our spectrum obtained around the knee is almost independent of the primary mass composition and will be rated as most standard.The gradual steepening of the spectrum at lower energy may be in favor of shock acceleration at SNRs which suggests a considerable change in the relative abundance of the various cosmic ray nuclei as the energy increases, but its confirmation requires more direct information about the primary mass composition at energies around the knee.