The Yangbajain Cosmic Ray National Field Scientific Observatory in Tibet ( zh, 西藏羊八井宇宙线国家野外科学观测研究站), Tibet AS⁢γ Collaboration, or Yangbajing Cosmic Ray National Field Scientific Observatory, is one of the national field scientific observatories recognized by the Ministry of Science and Technology of the People's Republic of China.

History

The observatory station was founded in 1989 by Institute of High Energy Physics, and collaboration with Tibet University,

Southwest Jiaotong University Southwest Jiaotong University (SWJTU; ) is a national public science and engineering university in Chengdu, Sichuan, China. The university is affiliated with the Ministry of Education. It is a national key university co-sponsored by the Minis ...

Yunnan University Yunnan University (YNU; zh, s=云南大学, p=, labels=no) is a provincial public university in Kunming, Yunnan, China. It is affiliated with the province of Yunnan, and co-funded by the Yunnan Provincial People's Government and the Ministry o ...

and

University of Tokyo The University of Tokyo (, abbreviated as in Japanese and UTokyo in English) is a public research university in Bunkyō, Tokyo, Japan. Founded in 1877 as the nation's first modern university by the merger of several pre-westernisation era ins ...

, Japan. The observatory is located in the northern suburb of Lhasa, in the town of Yangbajain, at an altitude of 4,300 meters above sea level. The station is subordinate to the Institute of High Energy Physics of the

Chinese Academy of Sciences The Chinese Academy of Sciences (CAS; ) is the national academy for natural sciences and the highest consultancy for science and technology of the People's Republic of China. It is the world's largest research organization, with 106 research i ...

. The station is the first and only station to have a

cosmic ray Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the ...

observation window of 1013eV. Since EAS has been developed to such an extent that precise measurements can be made, the station is the best site for high-altitude cosmic ray observatories in the world, and holds an important position in the international cosmic ray observation and research field. In 1990, CAS and the

in Japan, cooperated in the ASγ experiment, gradually increasing the scope of cooperation and establishing the Sino-Japanese Cooperation

Neutron The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...

Telescope, the Sino-Japanese Cooperation Neutron Monitor, the Latex Chamber, and so on. The Yangbajain Observatory also carried out the ARGO-YBJ experiment, a Chinese-Italian collaboration. At a later stage of the ARGO-YBJ experiment, the ASγ experiment was upgraded with the addition of a muon detector and a core detector. In 2007, the research station was approved to be established as a National Field Scientific Observation Research Station. On October 12, 2009, the "Tibet Yangbajain Cosmic Ray National Field Scientific Observatory" and the "International Scientific and Technological Cooperation Base" awarded by the Ministry of Science and Technology were held at the station. On July 3, 2019, the Institute of High Energy announced that the Yangbajing ASγ experiment had detected cosmic gamma rays at 450 TeV from the direction of the

Crab Nebula The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus (constellation), Taurus. The common name comes from a drawing that somewhat resembled a crab with arm ...

, the first detection of photons above 100 TeV.

References

{{Lhasa 1989 in Lhasa Chinese Academy of Sciences Science and technology in Tibet University of Tokyo