A5070694888- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Photocathodes and Microchannel Plates
- Physics of Superconductivity and Magnetism
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Electron and X-Ray Spectroscopy Techniques
- Orbital Angular Momentum in Optics
- Advanced X-ray Imaging Techniques
- Radiation Therapy and Dosimetry
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Terahertz technology and applications
- Spectroscopy and Laser Applications
- Atomic and Subatomic Physics Research
- Magnetic Field Sensors Techniques
- Laser Design and Applications
- Magnetic properties of thin films
- International Science and Diplomacy
- Atmospheric Ozone and Climate
- Spacecraft and Cryogenic Technologies
Michigan State University
2023-2024
High Energy Accelerator Research Organization
2009-2023
The Graduate University for Advanced Studies, SOKENDAI
2010-2021
Institute for Molecular Science
2013-2018
National Institutes of Natural Sciences
2014-2018
Toyota Motor Corporation (Switzerland)
2014
Laboratoire de Physique des Lasers, Atomes et Molécules
2014
Centre National de la Recherche Scientifique
2014
Nagoya University
2008-2010
Hitachi (Japan)
2009
We theoretically show that a single free electron in circular/spiral motion radiates an electromagnetic wave possessing helical phase structure and carrying orbital angular momentum. experimentally demonstrate it by double-slit diffraction on radiation from relativistic electrons spiral motion. twisted photons should be created naturally cyclotron/synchrotron radiations or Compton scatterings various situations cosmic space. propose promising laboratory vortex photon sources wavelengths...
In order to produce a high brightness and spin polarization electron beam, pointlike emission mechanism is required for the photocathode of GaAs polarized source. For this purpose, laser spot size on must be minimized, which realized by changing direction injection light from front side back photocathode. Based concept, 20kV gun was constructed with transmission including an active layer GaAs–GaAsP superlattice layer. This system produces diameter as small 1.3μm 760–810nm wavelength. The...
We developed a spin-polarized low energy electron microscopy (SPLEEM) with highly polarized and high brightness spin gun in the present study. Magnetic structures of Co/W(110) were observed an acquisition time 0.02 s field view 6 µm. carried out dynamic observation magnetic SPLEEM during growth Co on W(110).
Abstract The Facility for Rare Isotope Beams (FRIB) began operation with 1 kW beam power scientific users in May 2022 upon completion of 8 years project construction. ramp-up to the ultimate 400 kW, planned over a 6-year period, will enable facility reach its full potential discovery isotope science and applications. In December 2023, record-high 10.4 uranium was delivered target. Technological developments accelerator improvements are being made entire key ramp-up. Major technological...
Suppression of the occurrence remanent vortices is necessary to improve quality factor superconducting resonators. In particular, flux-expulsion dynamics in Nb during cooling has become major interest researchers focusing on cavities. To study vortex states and their behavior high-purity cavity-grade Nb, we used a magneto-optical imaging technique perform real-space observations magnetic field distributions field-cooling field-scanning processes. process, were observed undergo phase...
A 750 MeV low energy synchrotron light source, UVSOR, has been operational since 1983. To meet the strong demands for brighter light, an upgrade project was performed in 2003, which emittance reduced from 160 nm-rad to 27 and four 1.4-m long short straight sections were created. Thereafter, source renamed UVSOR-II. During ten years after this major upgrade, we have continued upgrading source. The top-up injection scheme introduced a new 4-m section created by moving point. In 2012, bending...
Photoelectron angular distributions from helium atoms are measured using the circularly polarized extreme ultraviolet (XUV) vortex produced by a helical undulator as higher harmonics of its radiation. The XUV has wave front and carries orbital momentum well spin associated with circular polarization. While violation electric dipole transition rules been predicted for interactions between vortices atoms, photoelectron reproduced assuming transitions only. This observation can be explained...
We propose a scheme to produce structured light in synchrotron sources. In this scheme, beams from two undulators are superposed by using technique akin the “cross undulator.” demonstrate that vector beam, which polarization direction varies with azimuthal angle about beam axis, is produced superposing harmonic radiation helical tandem. Although demonstrated ultraviolet range at low-energy UVSOR-III, it can be applied high-energy synchrotrons x-ray beams, would open new field application of...
Development of a laser Compton scattering (LCS) gamma-ray source in the UVSOR-III storage ring has been proposed to perform basic research on non-destructive three dimensional isotope imaging. As first step development, numerical simulation was performed evaluate performance source. The expected total flux is about 1×107 photons/s when 1.94-μm CW fiber with maximum power 5 W collides 300-mA electron beam circulating ring. energy and available were measured experiment determined as 5403 ± 16...
Relativistic electron bunches circulating in accelerators are subjected to a dynamical instability leading microstructures at millimeter centimeter scale. Although this is well-known fact, direct experimental observations of the structures, or field that they emit, remained up now an open problem. Here, we report direct, shot-by-shot, time-resolved recording shapes (including envelope and carrier) pulses coherent synchrotron radiation emitted, "signature" bunch microstructure. The...
The behavior of submicrometer-sized thin-film <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="TeX">$\hbox{YBa}_{2}\hbox{Cu}_{3}\hbox{O}_{7-{\rm x}}$</tex-math></inline-formula> (YBCO) detectors under illumination with picosecond terahertz (THz) pulses was investigated. Real-time measurements a temporal resolution 15 ps full width at half maximum were performed ANKA, the synchrotron facility Karlsruhe Institute...
Energy recovery linac(ERL)-based free electron lasers(FELs) are promising candidates for high-power EUV sources. They can recover most acceleration energy from the beams and greatly reduce dumped beam power activation compared with those based on ordinary linear accelerators. We have investigated a feasible design of 10-kW class ERL-FEL operated at 13.5 nm lithography applications. In this talk, we will present work as source.
High-Q operation of a superconducting radio frequency cavity can reduce the power loss at surface and is desirable for continuous-wave operation. To realize high-Q operation, resistance, which sum Barden-Cooper-Schrieffer resistance residual needs to be reduced. The has been found originate primarily from magnetic flux trapping in defects during cooling down process. A magnetometer called “flux gate sensor” used measure ambient field; however, this larger comparison with it very expensive....
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Fumio Furuta, Kenji Saito, Taro Konomi; Large Grain Cavity R&D in KEK. AIP Conference Proceedings 31 March 2011; 1352 (1): 169–177. https://doi.org/10.1063/1.3579235 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Dropdown Menu input...
Trapped magnetic flux in bulk superconductors reduces the quality factor Q superconducting radio-frequency (SRF) cavities. However, mechanisms underlying trapping and loss are not well understood. Detailed observation of distributions is important for understanding such phenomena. Magnetic field mapping useful observing distribution around SRF Measuring change cavity elucidates behavior. Anisotropic magnetoresistive (AMR) sensors inexpensive small devices that can detect density. The...
We have investigated linearly polarized UV and circularly light-induced molecular orientation, namely increasing optical anisotropy of newly synthesized AZ containing chiral Schiff base Ni (II), Cu (II) Zn complexes, as organic/inorganic hybrid materials in polymethylmethacrylate (PMMA) cast films. The driving force reason for orientation is so-called Weigert effect. increase the dichroic was measured with absorption electronic spectra. In addition, we study on composites metal complexes to...