A5089942650- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Astrophysics and Cosmic Phenomena
- Gyrotron and Vacuum Electronics Research
- Dark Matter and Cosmic Phenomena
- Superconducting Materials and Applications
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Muon and positron interactions and applications
- High-Energy Particle Collisions Research
- Advanced X-ray Imaging Techniques
- Neutrino Physics Research
- Magnetic confinement fusion research
- Radiation Therapy and Dosimetry
- Gamma-ray bursts and supernovae
- Crystallography and Radiation Phenomena
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Atomic and Subatomic Physics Research
- Quantum Chromodynamics and Particle Interactions
- Plasma Diagnostics and Applications
- Radiation Detection and Scintillator Technologies
- Radioactivity and Radon Measurements
- Pulsed Power Technology Applications
High Energy Accelerator Research Organization
2007-2024
The Graduate University for Advanced Studies, SOKENDAI
2019
The University of Tokyo
2000-2017
Iwaki Kyoritsu General Hospital
1998
Universidade Federal Fluminense
1995
Sumitomo Electric Industries (Japan)
1994
Nissan (United Kingdom)
1992
Aoyama Gakuin University
1992
Japan Atomic Energy Agency
1989
Advanced Science Research Center
1988
The machine commissioning of KEKB started in December 1998 and its operation was terminated at the end June 2010 to upgrade SuperKEKB. In this paper, we summarize history show achievements made there.
This paper introduces a new approach to measure the muon magnetic moment anomaly |$a_{\mu} = (g-2)/2$| and electric dipole (EDM) |$d_{\mu}$| at J-PARC facility. The goal of our experiment is |$a_{\mu}$| using an independent method with factor 10 lower momentum, 20 smaller diameter storage-ring solenoid compared previous ongoing |$g-2$| experiments unprecedented quality storage field. Additional significant differences from present experimental include 1000 transverse emittance beam...
An experiment to search for the production of neutral penetrating particles decaying into electron-positron pairs was performed with a 2.5-GeV electron beam. A total 0.027 C injected tungsten target. No such particle is found. Constraints on coupling constants ${\ensuremath{\alpha}}_{e}$ and ${\ensuremath{\alpha}}_{\ensuremath{\gamma}}$ are given.
The KEKB injector linac has been continuously improved to enhance the stability of many devices and efficiency beam operation. These improvements include development new C-band accelerating structure, pulse compressor, klystron, rf window, compact modulator, positron production target using crystalline tungsten. We have also achieved two-bunch acceleration, an energy spread monitor, a safety system upgrade, event-based timing control system. developments practical applications for advanced...
The KEKB electron/positron injector linac is under the upgrade for SuperKEKB. A new positron source with a target, beam spoiler, flux-concentrator and large-aperture S-band accelerating structures inside DC solenoids an separator have been installed. Preliminary commissioning has started. first observed after upgrade. construction status of recent performance are reported.
Recent development of the Slow Positron Facility at Institute Materials Structure Science, High Energy Accelerator Research Organization (KEK) is reported. The facility, equipped with a dedicated 55 MeV linac, provides high-intensity, pulsed slow-positron beam. beam produced in production unit high tension up to 35 kV and guided magnetically through grounded line, then branched using compact branching units experiment hall. An overview, some details three experiments currently conducted...
Intense positron sources are being widely investigated for the next-generation linear colliders and B factories. A new method utilizing an axially oriented crystal as a positron-production target is one of bright schemes, since it provides powerful photon source through channeling coherent bremsstrahlung processes when high-energy electrons penetrate target. series experiments with tungsten crystals hit by 4- 8-GeV single-bunch electron beams were carried out at KEKB injector linac. Three...
The history of the KEKB commissioning is characterized by struggles with three obstacles, namely electron-cloud instability, beam-beam blowup and beam current limitations from many reasons. A rapid improvement in luminosity this year (2001) has been made progress each these problems. This report summarizes year's accelerator, since prior days covered other reports.
The Slow Positron Facility at the Institute of Material Structure Science (IMSS) High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 – 35 keV) slow positron beam produced by 55MeV linac. present line branches have been used for positronium time-of-flight (Ps-TOF) measurements, transmission microscope (TPM) and photo-detachment Ps negative ions (Ps−). During year 2010, reflection high-energy diffraction (RHEPD) measurement station going...
Simultaneous observations of families and accompanied air showers with emulsion chambers the shower array electronic equipment at Mt. Chacaltaya (5200 m, 540 g/${\mathrm{cm}}^{2}$) reveal that bear data nuclear interactions generated deep in atmosphere. 47 outstanding \ensuremath{\Sigma}${\mathit{E}}_{\ensuremath{\gamma}}$\ensuremath{\ge}10 TeV are correlated size ${10}^{5}$--${10}^{8}$. A scatter plot average family energy versus relative requires further fractionizing process(es)...
An experimental setup of an air shower array, hadron calorimeter, and emulsion chamber is being carried out at Mt. Chacaltaya (5200 m, Bolivia), in order to study the interaction primary cosmic rays energy region exceeding ${10}^{15}$ eV. The number hadrons shower, detected by discussed mainly this paper. A comparison with simulation shows that not compatible simulation, indicating Feynman scaling law violated more strongly than one assumed ${10}^{16}$ average mass rays, estimated from...
Crab cavities have been installed in the KEKB B-factory rings to compensate crossing angle at collision point and thus increase luminosity. The beam operation with crab has done since February 2007. This is first experience such colliders or storage rings. working without serious issues. While higher specific luminosity than geometrical gain achieved, further study necessary under way reach prediction of simulation.