> KEK top > Accel. Lab. > TOP

The Accelerator Laboratory provides foundation to scientific research at KEK

Particle accelerators are the basis of all research activities carried out at High Energy Accelerator Research Organization (KEK). KEK would even lose the reason for its existence, if it did not have particle accelerators. The Accelerator Laboratory (ACCL) operates all accelerators at KEK, and develops the performance of the beam, which provides the basis of all corporative experiment on elementary particles and nuclear physics and also material and life sciences, etc., for researchers in Japan and the world. It is also endeavoring to research and develop future accelerators and related technologies.

At Tsukuba Campus, ACCL has started the operation of SuperKEKB B-Factory (electron-positron colliding rings with an injector linac) toward higher-performance beam by upgrading KEKB B-Factory, which gave experimental verification to Kobayashi-Maskawa theory to win 2008 Nobel Prize in Physics. It also operates two rings at Photon Factory (PF and PF-AR), which is a pioneer of synchrotron light sources in the world as well as Slow Positron Facility. Also it performs R&D for the KEK LS as one of the candidates for future light source. In addition, developments for the International Linear Collider (ILC) have been done at experimental accelerators ATF and STF.

At Tokai Campus, ACCL has already started the operation of J-PARC for user’s experiments together with JAEA, and is paying a lot of efforts to improve beam performance with conquering various issues accompanied by a high intensity proton beam.

ACCL has conducted collaboration research with various accelerator laboratories and researchers in the world, including the United States (Fermilab, SLAC, Cornell Univ., JLab, etc.), Asia (IHEP-Beijing, Shanghai, Pohan, Taiwan, BINP, RRCAT etc.) and Europe (CERN, DESY, INFN, CEA, STFC etc.). Furthermore, collaborating with companies or other organizations, ACCL promotes R&D of accelerators for medical application and industrial application.

New Topics

titleAccelerator Laboratory Newstitle

・To KEK users: Update on the fire in the accelerator structure assembly room at the electron-positron injector linac building (2019.4.26)
INFO Dear KEK Users, The electron-positron injector linac has been brought back on line, with great support and assistance from many people in and outside KEK. ---more

・To KEK Users: On the fire in the accelerating structure assembly room at the electron-positron injector linac (2019.4.11)
INFO Dear KEK Users, We sincerely apologize for the great inconvenience and concern arising from this fire. We are also deeply appreciative of the understanding and offers of assistance. ---more

・Fire in the accelerator structure assembly room at electron-positron injector linac (2019.4.9)
press At 9:44 pm on April 3rd, on the KEK Tsukuba campus, a fire alarm went off in the accelerator structure assembly room at electron-positron injector linac (a general radiation area) and the fire department was called to the site.
The cause of the alarm was determined to be an electric pulse modulator used in microwave power source, which had suffered a burnout. This event did not cause any human injuries or radiation leakage. We apologize to everyone for any concern or alarm. ---more

・Kick-off of the Belle II Phase 3 Physics Run (2019.3.26)
press On March 25 19:44 (JST), 2019, electron-positron collisions have restarted at the SuperKEKB collider, and the Belle II experiment has now kicked off its physics data taking. Belle II is now fully instrumented with a state-of-the-art vertex detector, just in time for the start of the cherry blossom season in Japan. ---more

・SuperKEKB Phase 3 (Belle II Physics Run) Starts (2019.3.12)
press On March 11th, 2019, Phase 3 operation of the SuperKEKB project began successfully, marking a major milestone in the development of Japan’s leading particle collider. This phase will be the physics run of the project, in which the Belle II experiment will start taking data with a fully instrumented detector. ---more

・Minuscule Gremlins Cause Vacuum Breakdown
in Radio-Frequency Accelerating Cavities
accloriginal Radio-frequency (RF) accelerating cavities (hereinafter referred to simply as RF cavities) are at the heart of many modern particle accelerators. An RF cavity is a metal resonator that can store high-energy microwaves to accelerate charged particles by the high-electric field of the stored microwaves. ---more

(topics linked 2019.1.23)

・Under Secretary for Science of U.S. DOE visited KEK (2016.10.24)
topics The Honorable Paul M. Dabbar, Under Secretary for Science of United States Department of Energy (DOE) visited KEK’s Tsukuba campus on October 9th. ---more

・Electrons and Positrons Collide for the first time in the SuperKEKB Accelerator (2018.4.26)
press Electrons and positrons accelerated and stored by the SuperKEKB particle accelerator collided for the first time on 26 April 2018 0:38, GMT+09:00 at KEK in Tsukuba, Japan. The Belle II detector, installed at the collision point, recorded events from electron-positron annihilation (matter-antimatter annihilation) of the beam particles, which produced other particles likely including beauty quark and anti-beauty quark pairs as well as other hadronic and Bhabha scattering events1. ---more

・SuperKEKB accelerator kicks into new gear (2018.3.28)
press KEK has begun a new stage of operation of the SuperKEKB electron-positron collider, with a brand new positron damping ring and the Belle II detector. Electron and positron beams will begin colliding soon for the first time in 8 years, since the previous KEKB collider ceased its operations in 2010. ---more

・The IHEP-KEK 2017 Collaboration Meeting held in Tsukuba (2017.9.29)
topics On September 7 and 8, ten delegation members led by Dr. Yifang WANG , Director of the Institute of High Energy Physics (IHEP), Chinese Academy of Sciences visited KEK Tsukuba campus to have a top-level collaboration meeting, which has a history of more than fifteen years. At the end of the meeting, both institutes signed a MoU for "R&D for high luminosity colliders ("MNPP-01 Project")" under the framework of Multinational Partnership Laboratory's Initiative. ---more

・The President of INFN in Italy Visit KEK Tsukuba to Discuss the Current and Future Collaboration (2017.9.13)
topics On August 31, 2017, Prof. Fernando Ferroni, President of the National Institute of for Nuclear Physics (INFN) in Italy visited KEK Tsukuba campus to discuss the current and future collaboration between INFN and KEK. KEK Director General, Dr. Masanori Yamauchi, Executive Director, Dr. Yasuhiro Okada, the KEK and Italian researchers working on Belle II and T2K experiments warmly welcomed the delegation. ---more

・previous news   

・origin list     

News@KEK / Highlights Accl. topics

・First Beam Experiment by the Collaboration between 3 Nations: Japan, UK and USA (2011.06.23)
After 15 years of waiting the first tests of a novel Low Output Impedance (LOI) acceleration system with beam in the ISIS proton synchrotron at the Rutherford Appleton Laboratory (RAL), UK, were completed on April 17, 2011. The system was quite stable under high-intensity beam current, and the output impedance was measured to be as low as 35ohms, which is almost the design value and about 40 times lower than that in the existing acceleration systems. There is still much more work to do to make this system – or something like it – an operational part of a real synchrotron, but the initial results are very promising. This approach may point the way towards upgrades of existing accelerators and future high-intensity ones. ---more
(highlights linked 2011.06.23)

・Accelerated Higher Intensity Heavy Ion Beam with New Linac System (2011.04.14)
Research Laboratory for Nuclear Reactors in Tokyo Institute of Technology had developed a multi-beam type RFQ (Radio Frequency Quadrupole) linac system accelerating several heavy ion beams in parallel in one cavity. This system has made it possible for generating high intensity heavy ion beams, never before possible such as 100 mA and more, without growing the machine scale. ---more
(highlights linked 2011.04.14)

・Japanese 9-cell SCRF cavity meets ILC specifications (2010.12.09)
Designing and fabricating an optimal accelerating cavity is not so simple. There are two important parameters scientists are looking for: the gradient of 35 megavolts per meter (MV/m) and the quality factor (Q0) of greater than 8×109. A Japanese cavity now fulfilled those requirements for the first time at a test which took place at the Superconducting radiofrequency Test Facility (STF) at KEK, adding momentum towards future mass production. ---more

(highlights linked 2010.12.09 / ILC Newsline linked 2010.12.09 )

・Start operation of the Small Electron Linear Accelerator for calibration of the Fluorescence Detector of the Telescope Array experiment (2010.10.14)
The Telescope Array ( TA ) experiment is a ultra-high energy cosmic rays ( UHECRs ) observation which is established in the desert area about 200 km far from Salt Lake City in Utah state, north U.S. We began the observation in April 2008. The UHECRs are the highest primary cosmic rays which have energy more than 1018 eV. However, we do not understand any fundamental features, for example the chemical composition, their generation and acceleration mechanism, and the theoretical flux limit ( GZK-cutoff ). ---more

(highlights linked 2010.10.21)


dotUsing Crab Cavities, KEKB Breaks Luminosity World Record (Current operation summary) (2009.6.18)
 Peak Luminosity2.1083 x 1034 cm-2 s-1 (2009.6.17 17:12)
 Daily Integrated Luminosity 1.4794 /fb (2009.6.14)

dotInternational collaboration at KEKB
 ■Global Collaboration Between KEKB and LHC on Crab Cavities(2008.10.3)

 ■CesrTA project at Cornell University(2008.9.29)

dotAgenda of the 13th KEKB Accelerator Review Committee-11/29 - 12/5, 2007-

dotBreakthrough in Accelerator Physics:Crab cavities are operated successfully for the first time (2007.07.03)

titleNobel Prizetitle

・Nambu, Kobayashi and Maskawa win the 2008 Nobel Prize for Physics.(2008.10.7)
Kobayashi and Maskawa are awarded for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature.

The Accelerator that Proved the Nobelists' Theory: KEKB

The Nobel Prize in Physics 2008

On Wednesday, 24 September, KEK held a symposium entitled "Starting up the world's most powerful accelerators: LHC and J-PARC" in Tokyo. This symposium was the second one in a series of symposiums aiming for gaining more understanding of accelerator science.

- previous news