A5036986308- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Gyrotron and Vacuum Electronics Research
- Particle physics theoretical and experimental studies
- 3D IC and TSV technologies
- Radiation Detection and Scintillator Technologies
- Muon and positron interactions and applications
- Advanced materials and composites
- Crystallography and Radiation Phenomena
- Freezing and Crystallization Processes
- Silicon Carbide Semiconductor Technologies
- Material Dynamics and Properties
- Powder Metallurgy Techniques and Materials
- Radio Frequency Integrated Circuit Design
- Laser-Plasma Interactions and Diagnostics
- Aluminum Alloys Composites Properties
- VLSI and Analog Circuit Testing
- Semiconductor materials and devices
- GaN-based semiconductor devices and materials
- Microencapsulation and Drying Processes
- Metal and Thin Film Mechanics
- Plasma Diagnostics and Applications
- Advanced Data Storage Technologies
High Energy Accelerator Research Organization
2014-2025
The Graduate University for Advanced Studies, SOKENDAI
2019-2024
KEK Accelerator Laboratory
2024
Nagoya University
2023-2024
Centre National de la Recherche Scientifique
2022
Université de Strasbourg
2022
Okayama University
2020
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2018
Sony (Taiwan)
2006
SuperKEKB is an electron-positron collider with asymmetric energies located at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan. After more than five years of upgrading work on KEKB, phase-1 commissioning commenced February 2016 and ended June same year. Following a 20-month shutdown for installation particle detector, BELLE II, phase-2 March 2018 July This paper describes one major issue faced by SuperKEKB: electron cloud effect (ECE) positron ring, which was...
The collimators in the SuperKEKB rings are indispensable for reducing beam background noise Belle II particle detectors and protecting essential components, such as final focusing superconducting quadrupole magnets, from beams that may deviate into abnormal orbits. This study developed a new robust collimator using carbon-fiber composite (CFC) head material to receive kicked by accidental firing of injection kicker. Simulation results confirmed CFC suppressed temperature rise caused hit...
A two-ring electron-positron collider with asymmetric energies—called the SuperKEKB—has been designed by High Energy Accelerator Research Organization (KEK) as an upgrade of KEKB B-factory (KEKB), which completed 12 years operation in 2010. It is anticipated that SuperKEKB will reach a luminosity 8 × 1035 cm−2 s−1, approximately 40 times larger than original KEKB. The vacuum system key factor allow to achieve unprecedented high performance. Most beam pipes, especially positron ring, are...
The first (Phase-1) commissioning of SuperKEKB, an asymmetric-energy electron-positron collider at KEK, began in February 2016, after more than five years upgradation work on KEKB and successfully ended June 2016. A major task the Phase-1 was vacuum scrubbing new beam pipes anticipation a sufficiently long lifetime low background noise next commissioning, prior to which particle detector will be installed. pressure rise per unit current decreased steadily with increasing dose, as expected....
Movable collimators for the SuperKEKB main ring, which is a two-ring collider consisting of 4 GeV positron and 7 electron storage were designed to fit an antechamber scheme in beam pipes, suppress background noise particle detector complex named Belle II, avoid quenches, derived from stray particles, superconducting final focusing magnets. We developed horizontal vertical having pair horizontally or vertically opposed movable jaws with radiofrequency shields. The have large structure that...
The operation of the SuperKEKB has been ongoing since 2016. vacuum systems main ring (MR) which consists a 7-GeV electron (HER) and 4-GeV positron (LER), damping (DR) for 1.1 GeV positrons in middle injector linac have working well as whole. As June 2022, maximum stored beam currents MR are 1.46 1.14 A LER HER, respectively, approximately 30 mA DR. pressure increase per unit current is steadily decreasing new components developed expected. No significant cloud effect observed after...
In SuperKEKB, movable collimators reduce the beam background noise in Belle II particle detector and protect crucial machine components, such as final focusing superconducting quadrupole magnets (QCS), from abnormal losses. The challenges related to collimator, which were not properly considered at time of SuperKEKB design, have surfaced through experience with its operation. this paper, we report collimator operation strategy SuperKEKB. addition, a significant challenge collimation due...
Abstract The SuperKEKB is an electron-positron collider consisting of two storage rings: the 4 GeV-positron low-energy ring and 7 GeV-electron high-energy ring. impedance rings has been modeled using electromagnetic simulation codes used to study single-bunch collective instabilities. wake potentials are exported from model included in a particle tracking code, PyHEADTAIL. In this paper, we review modeling results instability simulations.
Mitigation of beam backgrounds via collimators is critical for the success Belle II experiment at SuperKEKB electron-positron collider. We report on an improved simulation methodology, which includes a refined physical description and pipe, our first implementation collimator tip scattering, in existing particle tracking software has been embedded into new sequential framework. These improvements resolve longstanding discrepancies between measured predicted background levels, significantly...
The first (phase-1) commissioning of SuperKEKB, an asymmetric-energy electron–positron collider at High Energy Accelerator Research Organization, known as KEK, Japan, began in February 2016 and successfully ended June 2016. Three major tasks the phase-1 were follows: (1) vacuum scrubbing new beam pipes anticipation a sufficiently long lifetime next commissioning, (2) checking stabilities various components high currents approximately 1 A, (3) tuning to study stability achieve low emittance....
The SuperKEKB, the upgrade of KEKB, is an electron–positron collider with asymmetric energies, that is, 7.0 GeV electrons and 4.0 positrons, designed for a luminosity 8 × 1035 cm−2 s−1. As key item project, new vacuum system SuperKEKB has been in construction since 2010. Over 1000 beam pipes, pumps, bellows chambers, other various components had almost fabricated 2014. All pipes were baked as general rule before being installed KEKB tunnel. A thin TiN film low secondary-electron yield was...
As the vacuum system of highest-luminosity collider in world, components KEK B-factory have experienced many great demands. The experience strong electromagnetic interaction between and a beam charged particles led to invention robust rf bridge (a comb-type bridge). Through an intensive study electron cloud problem positron ring, sufficient set mitigation technologies for future high-current ring was established.
Abstract In the low energy ring (LER) for positrons in SuperKEKB, a vertical beam size blow-up was observed when bunch current approximately 1 mA. If occurs, design luminosity cannot be achieved. Therefore, blow-ups must pre-vented. According to calculations, threshold of transverse mode coupling instability (TMCI) is 2 mA or more, and value 50% smaller. Ordinary TMCI explain this blow-up. This paper shows that cause can determined by analyzing factors such as oscillation. The study results...
To satisfy the requirements of high beam quality for positron injection into SuperKEKB electron-positron collider, a new damping ring (DR) is constructed in an upgraded injector system. The DR has two arc sections and straight sections. In sections, pipes have position monitor blocks, pumping ports, radio-frequency-shielded bellows, special connection flanges to fit narrow spaces between closely located magnets. antechambers on both sides channel deal with synchrotron radiation (SR) which...