A5046491219- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Advanced X-ray Imaging Techniques
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Laser Design and Applications
- Crystallography and Radiation Phenomena
- Plasma Diagnostics and Applications
- Advanced Surface Polishing Techniques
- Laser-Plasma Interactions and Diagnostics
- Molecular Junctions and Nanostructures
- Physics of Superconductivity and Magnetism
- Copper Interconnects and Reliability
- Metal and Thin Film Mechanics
- Photocathodes and Microchannel Plates
- Semiconductor materials and devices
- X-ray Spectroscopy and Fluorescence Analysis
- Photonic and Optical Devices
- Spacecraft and Cryogenic Technologies
- Nuclear Physics and Applications
- Pulsed Power Technology Applications
- Advancements in Photolithography Techniques
- Radiation Detection and Scintillator Technologies
High Energy Accelerator Research Organization
2014-2025
Japan Atomic Energy Agency
2024
Kyoto University
2024
Nippon Soken (Japan)
2023
The Graduate University for Advanced Studies, SOKENDAI
2002-2019
Tokyo Metropolitan Institute of Medical Science
2003-2004
Waseda University
2002
Stanford Synchrotron Radiation Lightsource
2000
SLAC National Accelerator Laboratory
2000
Tokyo Metropolitan University
1999
A system for inspecting the inner surface of superconducting rf cavities is developed in order to study relation between achievable field gradient and defects surface. The inspection consists a high resolution complementary metal-oxide-semiconductor camera special illumination built cylinder that has diameter 50 mm. can be inserted into L-band 9 cell cavity. provides about $7.5\text{ }\text{ }\ensuremath{\mu}\mathrm{m}/\mathrm{pixel}$. Thus far, there have been good correlations locations...
A high-current, long-pulsed beam operation without loss was demonstrated at the Superconducting rf Test Facility (STF) of High Energy Accelerator Research Organization. The primary purpose STF to validate superconducting radio-frequency (rf) acceleration technology for International Linear Collider (ILC) using accelerator components in line with ILC design. Thus, most critical objective perform operations a pulse length (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...
First experimental results from the final focus test beam (FFTB) are reported. The vertical dimension of a 47-GeV electron SLAC linac has been reduced at focal point FFTB by demagnification 320 to height approximately 70 nm.
An experiment on the investigation of optical diffraction radiation (ODR) from a slit target as possible tool for noninvasive electron beam-size diagnostics has been performed at KEK accelerator test facility. The experimental setup installed section extraction line. We have first incoherent ODR observation target. measured angular distributions are in reasonable agreement with theoretical expectation. effect onto pattern observed. Moreover, sensitivity to beam size small 14 microm achieved.
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...
For high luminosity in electron-positron linear colliders, it is essential to generate low vertical emittance beams. We report on the smallest achieved single-bunch-mode operation of Accelerator Test Facility, which satisfies requirement x-band collider. The emittances were measured with a laser-wire beam-profile monitor installed damping ring. bunch length and momentum spread beam also recorded under same conditions. rms at intensity 4 pm energy 1.3 GeV, corresponds normalized 1.0x1.0(-8)...
We have developed a high-resolution cavity-beam position monitor (BPM) to be used at the focal point of ATF2, which is test beam line that now being built demonstrate stable orbit control $\ensuremath{\sim}\mathrm{\text{nanometer}}$ resolution. The design cavity structure was optimized for Accelerator Test Facility (ATF) in various ways. For example, has rectangular shape order isolate two dipole modes orthogonal directions, and relatively thin gap less sensitive trajectory inclination. A...
Superconducting radiofrequency (SRF) cavities for accelerators is the only superconductivity application that operates in Meissner state. For decades, bulk niobium, which exhibits highest 1st critical field among all known superconductors, has been material to achieve high accelerating fields combination with a quality factor. Specific nanostructures tailored SRF applications, form of superconducting/insulating/superconducting multilayers, were proposed surpass Nb performances could improve...
Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of Accelerator Test Facility at KEK. We established a tuning method damping ring which achieves small vertical dispersion x-y orbit coupling. The was less than 1% horizontal emittance. At zero-intensity limit, 2.8 x 10(-8) rad m beam energy 1.3 GeV. high intensity, strong effects intrabeam scattering observed, had been expected view extremely particle...
An experiment to investigate the diffraction radiation from a single edge target has been performed at accelerator test facility of KEK with aim developing noninvasive beam diagnostics. The yield and angular distribution as function impact parameter was measured in visible light region. distributions were qualitatively consistent theoretical expectation. This work exhibits first observation incoherent
During the past five years, there has been an concerted program at SLAC and KEK to develop accelerator structures that meet high gradient (65 MV/m) performance requirements for Next Linear Collider (NLC) Global (GLC) initiatives. The design resulted is a 60-cm-long, traveling-wave structure with low group velocity 150 degree per cell phase advance. It average iris size produces acceptable short-range wakefield, dipole mode damping detuning adequately suppresses long-range wakefield. More...
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.
With the recent progress in surface cleaning, performance of superconducting RF cavities is mostly limited by a quench. It important to understand nature quench origin. In common SRF cavity design magnetic field concentrated near equatorial weld cavity. This has long been major suspect forming defect, either as an impurity or increased roughness, that eventually gives rise We used mounted thermometers obtain temperature map region. A high temperature, temporal, and spatial resolution...
The International Linear Collider (ILC) damping ring (DR) injection and extraction kickers have a very special role: the bunch spacing 189--480 ns is compressed to 3--9 when injected into DR then decompressed leaving DR. act as bunch-by-bunch beam manipulator compress decompress into/from They require fast rise/fall time (3--9 ns) high repetition rate (6--2 MHz). Among candidate technologies, multiple strip-line kicker system most likely realize specifications for ILC reference design. A...
We derive a simple relation for estimating the relative emittance growth in $x$ and $y$ due to intrabeam scattering (IBS) electron storage rings. show that IBS calculations Accelerator Test Facility (ATF) damping ring, when using formalism of Bjorken-Mtingwa, modified Piwinski (where ${\ensuremath{\eta}}^{2}/\ensuremath{\beta}$ has been replaced by $H$), or high-energy approximate formula all give results agree well. Comparing theory, including effect potential well bunch lengthening, with...
A compact soft x-ray source using Thomson scattering, enabled by the combination of a picosecond laser and an electron rf gun, was developed aiming at biological studies such as those microscope. The included both photoinjector system with tabletop size 2×2m2. An infrared beam (λ0=1047nm) obtained from all-solid-state mode-locked Nd:YLF injected into photocathode accelerator system. 4.2MeV generated laser-driven gun residual amplified up to about 4.2mJ/pulse flash-lamp-pumped amplifier. Upon...
A compact tunable monochromatic (1 to 10 percent bandwidth rms) hard X-ray source based on laser-electron collisions for medicine is proposed. An X-band linac introduced realize a remarkably system. We have designed as demonstration. (11.424 GHz) the purpose being manufactured. Numerical considerations using CAIN code and luminosity calculations been performed estimate yield. thermionic-cathode RF gun an RDS (round detuned structure) accelerating structure are applied generate 50 MeV...
We report the results of surface characterizations niobium (Nb) samples electropolished together with a single cell superconducting radio-frequency accelerator cavity. These witness were located in three regions cavity, namely at equator, iris, and beam pipe. Auger electron spectroscopy was utilized to probe chemical composition topmost four atomic layers. Scanning microscopy energy dispersive x ray for elemental analysis used observe topography micrometer scale. A few layers sulfur (S)...