Development of high-energy particle astrophysics in Tibet

西藏羊八井现有的空气淋浴阵列于2003年秋末建成，并已连续运行至今。该阵列（Tibet-III）由约800个闪烁计数器组成，以7.5米的间距部署，覆盖面积为37000平方米。空气簇射事件的触发率被设置为约1.7kHz，并且在超过3 TeV的能量区域中，每个事件的到达方向可以以小于0.9度的误差被估计。主要目标是寻找来自活跃天体的高能伽马射线，并研究极高能银河宇宙射线。这些观测对阐明宇宙线的起源和加速机制具有重要意义。迄今为止，我们获得的主要结果是：1）在10 ~ 10 μ eV的宽能量范围内观测到了全粒子宇宙线的能谱<14>，在<17>4 × 10 ~（15）eV附近有一个尖锐的膝状峰; 2）测量到了初级质子和螺旋粒子的能谱，发现了它们的能谱 ...更多信息 3）在蟹状星云和活动星系核Mrk 421和Mrk 501中成功地观测到了3 TeV以上的高能γ射线。观测到了来自XMM Newton卫星的RV γ射线和X射线耀斑之间的长期相关，提供了关于源处电子加速的信息。4）首次观测到银河宇宙线的大尺度各向异性的能量依赖性，并在天鹅座区域观测到了多TeV宇宙线的显著各向异性。去年我们在西藏空气簇射阵的地下建造了一个100平方米的水切伦科夫型μ子探测器。在不久的将来，μ子探测器的总面积将扩大到大约10000平方米。这种具有宽视野的仪器然后成为最敏感的？目前世界上最大的γ射线探测器是能量在10 TeV以上的几倍。预计这个实验使我们能够提供关于高能宇宙射线加速的非常重要的结果，这仍然是一个悬而未决的问题。少

The present air-shower array at Yangbajing in Tibet was completed in the late fall of 2003 and has then been successively operating to date. The array(Tibet-III) consists of about 800 scintillation counters, which are deployed at a grid of 7.5m spacing covering the area of 37000m^2. The trigger rate of air-shower events is set to about 1.7kHz and the arrival direction of each event can be estimated with an inaccuracy of less than 0.9 degrees in the energy region over 3 TeV. The main objectives are to search for high-energy gamma rays from active celestial objects and to study very high energy Galactic cosmic rays. These observations are very important to clarify the origin of cosmic rays and their acceleration mechanism.The main results obtained until now are as follows.1) The energy spectrum of all-particle cosmic rays has been observed in the wide energy range from 10^<14> to 10^<17> eV with a sharp knee at the energy around 4x1015 eV.2) The energy spectra of primary protons and heli … More ums are for the first time observed in the knee energy region.3) High energy gamma rays above about 3 TeV have been successfully observed from the Crab Nebula and active galactic nuclei such as Mrk421 and Mrk501. A long-term correlation between RV gamma-ray s and X-ray flares from XMM Newton satellite was observed to provide information about electron acceleration at the source.4) An energy dependence of the large-scale anisotropy of the Galactic cosmic rays has been for the first time observed and also significant anisotropy of multi-TeV cosmic rays is observed in the direction of Cygnus region.5) A variation of the sun shadow during the solar activity cycles was successively monitored with the air shower array, and we succeeded to get new information about the solar magnetic field.Last year we constructed a 100m^2 water-Cherenkov-type muon detector in the underground of the Tibet air shower array. The total area of muon detectors will be expanded up to about 10000m^2 in the very near future. This instrument with a wide field of view then becomes the most sensitive? gamma-ray detector at energies above several times 10 TeV in the world. It is expected that this experiment enables us to provide very important results on the acceleration of high energy cosmic rays, which is still unresolved. Less