Beijing Electron–Positron Collider II

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The Beijing Electron–Positron Collider II (BEPC II) is a Chinese electron–positron collider, a type of particle accelerator, located in Beijing, People's Republic of China. It has been in operation since 2008 and has a circumference of 240.4 m.[1]

It was intended as a charm factory and continues the role CLEO-c detector. The center of mass energy can go up to 4.6 GeV with a design luminosity of 1033 cm−2·s−1.[2] Operations began in summer 2008 and the machine has run at multiple energies.

BES III[edit]

The BES III (Beijing Spectrometer III) is the main detector[3] for the upgraded BEPC II.

BES III uses a large superconducting solenoid to provide a 1-tesla magnetic field, and also features a helium gas-based tracking chamber and an electromagnetic calorimeter using 6240 caesium iodide crystals.

See also[edit]


  1. ^ "Beijing Electron Positron Collider (BEPC)". Institute of High Energy Physics Chinese Academy of Sciences. 2004-01-09. Archived from the original on 2016-03-16. Retrieved 2015-10-15.
  2. ^ BESIII Collaboration (17 Aug 2009). "Charm Factories: Present and Future". AIP Conference Proceedings. 1182 (1): 406–409. arXiv:0908.2157. Bibcode:2009AIPC.1182..406Z. doi:10.1063/1.3293832. S2CID 118363265.
  3. ^ Minnesota BES-III home page