The Institute of High Energy Physics(IHEP) is the biggest and comprehensive fundamental research center in China. The major research fields of IHEP are particle physics, accelerator physics and technologies, radiation technologies and application, including the following leading research areas:

  • Particle physics experiments: BES, neutrino experiments, experiments at LHC and B-factories…

  • Theoretical Physics: particle physics, medium and high energy nuclear physics, cosmology, field theory…

  • Particle astrophysics: cosmic ray, astrophysics experiments…

  • Accelerator physics and technology: high luminosity e+e collider, high power proton accelerator, accelerator applications…

  • Synchrotron radiation: technology and application;

  • Nuclear analytical technique and application;

  • Free electron laser;

  • Nuclear detector and fast electronics;

  • Computing and network application;

  • Radiation protection.
    The main research facilities at IHEP are:

  • Beijing Electron Positron Collider (BEPC)

  • Beijing Spectrometer (BES)

  • Beijing Synchrotron Radiation Facility (BSRF)

  • Beijing Free Electron Laser (BFEL)

  • Particle Astrophysics Lab

  • Yangbajing International Cosmic Ray Observatory

  • Nuclear Analysis Lab

  • Intense Slow Positron Source

IHEP has extensive cooperation with all high energy physics laboratories and participates in many important particle physics experiments in the world.
IHEP is staffed with about 1000 people, including over 650 physicists and engineers. In addition, there are 300 graduate students and post-doctors.
Emeriti Directors: Zhang Wenyu, Ye Minghan, Fang Shouxian and Zheng Zhipeng.
Current Director: Chen Hesheng.

::::::::::  Beijing Electron Positron Collider  ::::::::::

BEPC is composed of the linear injector, the storage ring, Beijing Spectrometer (BES) and the Beijing Synchrotron Radiation Faclity (BSRF) . The positron injection energy is 1.3-1.5 GeV. The beam energy range of the storage ring is - 2.8 GeV with the luminosity of 1031cm-2s-1 at 1.89 GeV. The circumference of the storage ring is 240 meters. The beam energy for dedicated synchrotron radiation running is 2.2 GeV with beam current of 140mA. BEPC runs 10 months per year:5months for physics collision,3months for dedicated synchrotron radiation running and 2 months for machine starting and machine studies.

The BEPC Linac injector The modulator gallery of Linac The switchyard on the transport line for electrons and positrons

The BEPC RF cavity

An arc section of the

storage ring

4W2 in-vacuum insertion device 1W1 insertion device

::::::::::  Beijing Spectrometer  ::::::::::

Beijing Spectrometer (BES) is a general purpose magnetic spectrometer in the South IR of the storage ring. Its total weight is over 500 T, about 6 m long, 7 m high and 7 m wide. The central drift chamber, the main drift chamber, the shower counter and time of flight counter are installed in the solenoid magnetic field of 4000 Gauss. Surrounding the spectrometer is the muon detector. The physics window of BES is the tau-Charm physics. BES has accumulated the largest data samples of J/ψ and ψ' in the world. BES International Collaboration includes 18 Chinese institutes and universities, and 9 universities from U.S.A., Japan and Korea.


The maximum likelihood as a function for τ mass and detecting efficiency

R values at 91 energy ponints in 2-5 GeV were measured with the precision improvement by a factor of over 2.



::::::::::  Beijing Synchrotron Radiation  ::::::::::

The Beijing Synchrotron Radiation Facility(BSRF) has 4 insertion devices,13 beamlines and 13 experimental stations.It is the scientific facility open to public and provides SR light sources from VUV to hard X ray for interdisciplinary researches. Every year more than 300 experiments are carried out by about 100 insititutes from all over China, including condensed matter, life science, biomedicine, nano-science, materials science, chemistry and chemical industry, environmental science, pressure physics, earth science, metrology, geological resources and archeology, soft X ray optics, microelectronic technology, and LIGA......etc.

The East Synchrotron Radiation Experimental Hall

The West Synchrotron Radiation Experimental Hall and the newly-constructed Biological Macromolecular Crystallography Beamline

Structure of third type of light–harvester protein. The structure diffraction data taken at BSRF.

SARS protein CoV Mpro

Structure of MASA from MAD

Structure of CRISP Protein

::::::::::  Non-accelerator Physics  ::::::::::

Yangbajing International Cosmic Ray Observatiry(a.s.14300m),IHEP-INFN RPC(right),China-Japan Air Shower Array(left).

The ARGO Experimental Hall(IHEP-INFN Collaboration)

The ground prototype of hard X ray of modulation telescope(HXMT)satellite.


AMS01 permanent magnet undergoing vibration test in Beijing


::::::::::  BEPCII: Major Upgrade of BEPC  ::::::::::

BEPCII is a double-ring collider within the existing BEPC tunnel. The designed luminosity of BEPCII is l033cm-2s-l at the beam energy of 1.89GeV, which is about two orders of magnitudes higher that the one of BEPC. Each ring can be filled with up to 93 bunches with the maximum beam current of 0.9A per ring. The beams collide at the south interaction region with horizontal crossing angle of ±11 mrad.. Superconducting RF system of  500 MHz, superconducting Micro- beta quadruples, low impedance vaccum chambers Ö etc. are applied to reduce the beam length. The positron injection rate of linac will be increased to 50mA per minute with full energy injection up to 1.89 GeV. The upgrade of Beijing Spectrometer, so called BESIII will adapt to high event rate and small bunch spacing(8ns),improve the measurement precision and particle identification, and extend the solid angle acceptance as well as accommodate Micro-beta quadruples. The physics goal of BEPCII is the precision measurements of charm physics and search for new particles and phenomena. The synchrotron radiation running will still use the outer ring with the current of 250mA at 2.5GeV.The upgrade is expected to be finished by the end of2006,and the physics running is scheduled by spring 2007.


  The cutaway view of BESIII  

::::::::::  Other Research  ::::::::::

Beijing Free Electron Laser(BFEL) got lasing and saturated in 1993

The first 35 MeV proton linac built in 1985



R&D for key technologies of the high power proton linac

The BEPC-based intense slow positron beam facility


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mailing address:19B YuquanLu, Shijingshan District, Beijing, 100049

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Updated: 08- 25- 2004