T. Kamitani
A5114376400- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Particle physics theoretical and experimental studies
- Superconducting Materials and Applications
- Muon and positron interactions and applications
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Crystallography and Radiation Phenomena
- Gait Recognition and Analysis
- Radiation Detection and Scintillator Technologies
- Human Pose and Action Recognition
- Nuclear materials and radiation effects
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Magnetic confinement fusion research
- Anomaly Detection Techniques and Applications
- Hand Gesture Recognition Systems
- Video Surveillance and Tracking Methods
- SAS software applications and methods
- Advanced X-ray Imaging Techniques
- Plasma Diagnostics and Applications
- Atomic and Subatomic Physics Research
- Fusion materials and technologies
Tottori University
2017-2024
High Energy Accelerator Research Organization
2007-2023
The Graduate University for Advanced Studies, SOKENDAI
2023
Institut National de Physique Nucléaire et de Physique des Particules
2011
Centre National de la Recherche Scientifique
2011
Université Paris-Sud
2011
Tokushima University
1992
Tokyo Metropolitan University
1989-1992
University of Helsinki
1991
Osaka University
1986-1990
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.
The SuperKEKB project requires a positron and electron collider with peak luminosity of 8 × 1035 cm−2 s−1. This is 40 times that the KEKB B-factory, which operated for 11 years up to 2010. an asymmetry-energy double-ring collider; beam energy (LER) 4 GeV (HER) 7 GeV. An extremely small beta function at interaction point (IP) low emittance are necessary. In addition, in order achieve target luminosity, large horizontal crossing angle between two colliding beams adopted, as bunch length much...
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...
We report the first observation of B-->Dmacr;D(sJ)(2317) and B-->Dmacr;D(sJ)(2457) decays based on 123.8x10(6) BBmacr; events collected with Belle detector at KEKB. observe D(sJ)(2317) decay to D(s)pi(0) D(sJ)(2457) D(*)(s)pi(0) D(s)gamma final states. also set 90% C.L. upper limits for D(sJ)(2317)-->D(*)(s)gamma, D(sJ)(2457)-->D(*)(s)gamma, D(sJ)(2457)-->D(s)pi(0), D(sJ)(2457)-->D(s)pi(+)pi(-).
We present the first evidence of decay B -→ τ -ντ , using 414 fb -1 data collected at Υ(4S) resonance with Belle detector KEKB asymmetric-energy e + -collider.Events are tagged by fully reconstructing one mesons in hadronic modes.We detect signal a significance 3.5 standard deviations including systematics, and measure branching fraction to be B(B ) = (1.79+0.56 -0.49(stat) +0.46 -0.51 (syst)) × 10 -4 .This implies that fB 0.229 +0.036 -0.031 (stat) +0.034 -0.037 (syst) GeV is direct...
A possible design of a multi-TeV e+e- linear collider is presented. The based on the CLIC (Compact Linear Collider) two-beam technology proposed and developed at CERN. Though study has shown that this applicable to with centre-of-mass energies from 500 GeV or less up 5 TeV, present report focuses nominal energy 3 Te V. First, short overview given physics could possibly be done such collider. Then, description main-beam complex covers injection system, 30 GHz main linac, beam delivery system....
We present an improved measurement of CP-violation parameters in B0-->phiK(0)(S), K(+)K(-)K(0)(S), and eta(')K(0)(S) decays based on a 140 fb(-1) data sample collected at the Upsilon(4S) resonance with Belle detector KEKB energy-asymmetric e(+)e(-) collider. One neutral B meson is fully reconstructed one specified decay channels, flavor accompanying identified from its products. for each three modes are obtained asymmetries distributions proper-time intervals between two decays. find that...
We report the first observation of CP-violating asymmetries in B0 --> pi+pi- decays based on a 140 fb-1 data sample collected at Upsilon(4S) resonance with Belle detector KEKB asymmetric-energy e+e- collider. reconstruct one neutral B meson as CP eigenstate and identify flavor accompanying from its decay products. apply an unbinned maximum likelihood fit to distribution time intervals between two points. The yields asymmetry amplitudes Apipi = +0.58+/-0.15(stat)+/-0.07(syst) Spipi...
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...
A new tungsten single-crystal target has been successfully employed at the positron source of KEKB injector linac. The crystal thickness was determined to be 10.5 mm based on previous systematic measurements positron-production efficiency. axis, $⟨111⟩$, precisely aligned direction 4-GeV primary electron beam. yield increased by $\ensuremath{\sim}25%$ compared that for a conventional plate with 14 mm. On contrary, steady-state heat load decreased $\ensuremath{\sim}20%$. After two-month...
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.
The use of C-Band structures for electron acceleration and production high quality beams has been proposed adopted in several linac projects all over the world. two main that such type are Japanese Free Electron Laser (FEL) project Spring-8 SwissFEL at Paul Scherrer Institute (PSI). Also energy upgrade SPARC photo-injector LNF-INFN (Italy) from 150 to more than 240 MeV will be done by replacing a low gradient S-Band accelerating structure with C-band structures. Traveling Wave (TW) Constant...
Comparing to the previous KEKB, four-times higher charge of 4 nC per bunch is required for injector linac SuperKEKB. Not only a flux concentrator will be introduced but also physical aperture downstream six 2m-long accelerator structures was increased as large 30mm in diameter. We call these LAS, “Large Aperture S-band” structure. The resultant RF group velocity about 3% makes acceleration gradient lower. In nominal system, 40MW klystron with SLED feeds four producing 20MV/m field. than 14...
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.