A5063092442- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Advanced X-ray Imaging Techniques
- Crystallography and Radiation Phenomena
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Terahertz technology and applications
- Laser Design and Applications
- Particle Detector Development and Performance
- Advanced Optical Sensing Technologies
- Radiation Detection and Scintillator Technologies
- Photonic and Optical Devices
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting and THz Device Technology
- Optical Systems and Laser Technology
- Photocathodes and Microchannel Plates
- Advanced Electron Microscopy Techniques and Applications
- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Pulsed Power Technology Applications
- Geophysics and Sensor Technology
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Advanced Measurement and Metrology Techniques
- Bacteriophages and microbial interactions
High Energy Accelerator Research Organization
2013-2022
The Graduate University for Advanced Studies, SOKENDAI
2007-2020
St Petersburg University
2019
Royal Holloway University of London
2008-2010
Tomsk Polytechnic University
2002-2005
National Research Tomsk State University
2002-2005
The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in 2030s. ILC addresses key questions for our current understanding of particle physics. It based proven technology. Its experiments will challenge Standard Model physics and provide window to look beyond it. This document brings story up date, emphasizing its strong motivation, readiness construction, opportunity it presents US community.
In this paper we review the physics opportunities at linear $e^+e^-$ colliders with a special focus on high centre-of-mass energies and beam polarisation, take fresh look various accelerator technologies available or under development and, for first time, discuss how facility equipped technology mature today could be upgraded of tomorrow to reach much higher and/or luminosities. addition, will detectors alternative collider modes, as well beyond-collider experiments R\&D facilities part...
A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This has many advantageous properties over previously studied schemes, including being significantly shorter a given energy having better bandwidth. Experimental results from ATF2 accelerator at KEK are presented that validate operating principle such by demonstrating demagnification 1.3 GeV electron beam down to below 65 nm height...
The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the resolution cavity position monitor (BPM) system, which part ATF2 diagnostics. Two types BPMs are used, C-band operating at 6.423 GHz, and S-band 2.888 GHz with an increased aperture. cavities, electronics, digital processing described. attenuators was determined to be approximately 250 nm 1 m system. Without attenuation best recorded 27 nm.
We present the response time measurements of a Cs2Te photocathode illuminated with two 100 fs duration, variable separation laser pulses at 266 nm wavelength. The was confirmed in dispersive region downstream 12-cell standing wave S-band acceleration structure using well-known RF zero-crossing technique. At same it also measured by changing mechanical path-length difference between micro-bunches. Both methods agree that is order 250 and thereby possible to generate control THz sequence...
ATF2 is a final-focus test beam line which aims to focus the low emittance from ATF damping ring vertical size of about 37 nm and demonstrate nanometer level stability. Several advanced diagnostics feedback tools are used. In December 2008, construction installation were completed commissioning started, supported by an international team Asian, European, U.S. scientists. The present status first results described.
We represent the first experimental observation of point spread function (PSF) optical transition radiation (OTR) performed at KEK-Accelerator Test Facility extraction line. have demonstrated that PSF vertical polarization component has a central minimum with two lobe distribution. However, distribution width varied significantly wavelength. assume we observed severe effect from spherical or chromatic aberrations which are not taken into account in any existing theoretical model. believe...
This paper demonstrates the application of a polarization current approach to estimate yield soft x-ray Cherenkov radiation when charged particle travels in vicinity finite-size screen. To account for resonant anomalous dispersion complex permittivity, we apply formalism atomic scattering factor. We derived simple analytical expression field, which allows us determine all properties wide energy range emitted particle. The influence screen sizes on characteristics is determined by macroscopic...
Optical transition radiation (OTR) has become a commonly used method for 2D beam imaging measurements. In the Accelerator Test Facility 2 (ATF2) at KEK, sizes smaller than OTR point spread function have been measured. Simulations of system performed using ZEMAX software to study effects optical errors such as aberrations, diffraction, and misalignments components. This paper presents comparison simulations with experimental data obtained ATF2. It shows how quantification control impacts on...
We present recent achievements in the application of optical diffraction radiation (ODR) to measurement transverse beam size a 1.3 GeV micrometer-size electron performed with an instrument installed extended extraction line KEK Accelerator Test Facility. ODR is technique for and emittance highly relativistic particle beams. has advantage being noninvasive relatively inexpensive candidate operation linear accelerators, where no simple alternatives (e.g., synchrotron radiation) are available....
We report the results of experimental and theoretical studies monochromatic coherent terahertz radiation generated by a short relativistic electron bunch interacting with metasurface. The metasurface consists subwavelength metal elements arranged on dielectric substrate. constructed theory explains spectra Smith–Purcell grating transition very high precision. orientational distribution shows fine structure, which, as we suppose, may be due to contribution coupling between metasurface’s elements.
A laser-wire transverse electron beam size measurement system has been constructed and operated at the Accelerator Test Facility (ATF) extraction line KEK. The construction of is described in detail along with environment ATF related to laser wire. special set optics was developed generate an approximately $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ vertical focus location. results our operation are presented, where a minimum rms $4.8\ifmmode\pm\else\textpm\fi{}0.3\text{ measured, smaller...
Micro-bunched particle beams are used for a wide range of research including wakefield-based acceleration and tunable sources radiation. In all applications, accurate non-destructive monitoring the bunch-to-bunch separation is required. With development femtosecond lasers, generation micro-bunched directly from photocathode becomes routine; however, still challenge. We present results proof-of-principle experiments conducted at Laser Undulator Compact X-ray accelerator measuring distance...
Investigation of coherent Smith-Purcell radiation (SPR) spectral characteristics was performed both experimentally and by numerical simulation. The measurement SPR line shapes different diffraction orders carried out at the KEK LUCX facility. A pair room-temperature Schottky barrier diode (SBD) detectors with sensitivity bands 60--90 GHz 320--460 used in measurements. Reasonable agreement experimental results simulations CST Studio Suite justifies use narrow-band SBD to investigate orders....
The interest in producing ultrashort electron bunches has risen sharply among scientists working on the design of high-gradient wakefield accelerators. One attractive approach generating is to illuminate a photocathode with train femtosecond laser pulses. In this paper we describe and testing system for an rf gun based commercial titanium-sapphire technology. technology allows production four pulses continuously variable pulse delay. We also use designed demonstrate experimental generation...
The design of a compact Fabry-Pérot interferometer (FPi) and results the experimental studies carried out using device are presented. Our FPi uses freestanding wire-grid polarizers (WGPs) as beamsplitters is suitable for use at terahertz (THz) frequencies. was studied LUCX facility, KEK, Japan, an 8 MeV linear electron accelerator used to generate coherent Smith-Purcell radiation. designed be easy align reposition experiments facilities. All components were required have flat or well...
With a low emittance and short-bunch electron beam at high repetition rate realized by superconducting linac, stimulated excitation of an optical cavity the terahertz spectrum range is shown. The passes through small holes in mirrors without being destroyed. A sharp resonance structure which indicates wideband emission via coherent diffraction radiation observed while scanning round-trip length cavity.
Optical transition radiation (OTR) arising when a relativistic charged particle crosses boundary between two media with different optical properties is widely used as tool for diagnostics of beams in modern accelerator facilities. The resolution the beam profile monitors based on OTR depends effects system such spherical and chromatic aberrations diffraction. In this paper we present systematic study influencing monitor resolution. Obtained results have shown that can be sub-micrometer...
A laserwire transverse electron beam size measurement system has been developed and operated at the Accelerator Test Facility 2 High Energy Research Organization, Japan (KEK). Special optics were to create an approximately $1\ifmmode\times\else\texttimes\fi{}100\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ ($\text{vertical}\ifmmode\times\else\texttimes\fi{}\text{horizontal}$) location, which was profiled using 150 mJ, 71 ps laser pulses with a wavelength of 532 nm. The precise characterization...
Transition radiation (TR) and diffraction (DR) has widely been used for both electron beam diagnostics generation of intense beams in the millimeter submillimeter wavelength range. Recently, it was theoretically predicted that TR DR properties change either at extremely high energies electrons or long wavelengths. This phenomenon called a prewave zone effect. We have performed first observation detailed investigation effect optical 1.28 GeV KEK-Accelerator Test Facility (KEK-ATF). The energy...