A5075543096- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Photocathodes and Microchannel Plates
- Gyrotron and Vacuum Electronics Research
- Advanced X-ray Imaging Techniques
- Advancements in Photolithography Techniques
- Electron and X-Ray Spectroscopy Techniques
- Magnetic confinement fusion research
- Radiation Therapy and Dosimetry
- Particle Detector Development and Performance
- Laser Design and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- SAS software applications and methods
- Boron Compounds in Chemistry
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Radiation Detection and Scintillator Technologies
- Pulsed Power Technology Applications
- Advanced Chemical Physics Studies
- Plasma Diagnostics and Applications
- Advanced Electron Microscopy Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
High Energy Accelerator Research Organization
2013-2023
SLAC National Accelerator Laboratory
2023
The Graduate University for Advanced Studies, SOKENDAI
2016-2021
Cornell University
2007-2020
National Institutes for Quantum Science and Technology
2019
Japan Atomic Energy Agency
2014
Aichi Science & Technology Foundation
2014
Nagoya Industrial Science Research Institute
2014
Nagoya University
2014
Nagoya University Hospital
2014
The thermal emittance and temporal response of a photocathode set an upper limit on the maximum achievable electron beam brightness from photoemission source, or photoinjector. We present measurements these parameters over broad range laser wavelength for two different negative affinity (NEA) photocathodes. NEA GaAs GaAsP has been measured by techniques—a measurement size downstream solenoid, whose strength was varied, double slit transmission measurement—for spot sizes shapes. effect space...
Energy recovery has been achieved in a multipass linear accelerator, demonstrating technology for more compact particle accelerators operating at higher currents and reduced energy consumption. delivered to the beam during first four passes through accelerating structure was recovered subsequent decelerating passes. High-energy efficiency by use of superconducting cavities permanent magnets. The fixed-field alternating-gradient optical system used return loop successfully transported...
Narrow-bandwidth photon beams in the x-ray and γ-ray energy ranges are expected to be applied various fields. An recovery linac (ERL)-based laser Compton scattering (LCS) source employing a enhancement cavity can produce high-flux narrow-bandwidth beam. We conducted first experiment of an ERL-based LCS combination with cavity. obtained photons 6.95±0.01 keV by colliding electron beam 20 MeV 1064 nm wavelength. The flux at interaction point was evaluated (2.6±0.1)×107 photons/s average...
Abstract The development of a high-power EUV light source is very important in lithography to overcome the stochastic effects for higher throughput and numerical aperture (NA) future. We have designed studied free-electron laser (FEL) based on energy-recovery linac (ERL) future lithography. show that EUV-FEL has many advantages, such as extremely high power without tin debris, upgradability Beyond (BEUV) FEL, polarization controllability high-NA lithography, low electricity consumption,...
To achieve the lowest emittance electron bunches from photoemission guns, it is essential to limit uncorrelated growth due space charge forces acting on bunch in vicinity of photocathode through appropriate temporal shaping optical pulses illuminating photocathode. We present measurements profile a bulk crystal GaAs illuminated with 520 nm wavelength frequency-doubled Yb-fiber laser. A transverse deflecting rf cavity was used make these measurements. The measured laser pulse and...
We have developed a new beam injection system with single pulsed sextupole magnet (PSM) at the photon factory storage ring (PF ring) in High Energy Accelerator Research Organization. demonstrated this and succeeded storing current of 450 mA, which is normal operating PF ring. Top-up was also achieved. Coherent dipole oscillation stored fluctuation intensity observed synchrotron radiation lines during PSM became very small compared bump that normally used This experiment first demonstration...
We demonstrated the generation of a 500-keV electron beam from high dc voltage photoemission gun for an energy recovery linac light source [N. Nishimori et al., Appl. Phys. Lett. 102, 234103 (2013)]. This demonstration was achieved by addressing two discharge problems that lead to vacuum breakdown in gun. One is field emission generated central stem electrode. employed segmented insulator protect ceramic surface emission. The other microdischarge at anode electrode or chamber, which...
It is well known that a negative electron affinity GaAs photocathode shows moderate temporal response when excited by laser pulse of wavelength close to its band gap energy. We show here the can be estimated using diffusion model describes internal transport conduction electrons. Using transverse deflection cavity system, we measured profile bunch generated DC gun illuminated ps pulsed laser. A systematic set measurements cathodes with various active layer thicknesses and boundary conditions...
A high-voltage dc photocathode electron gun was successfully conditioned up to a voltage of 550 kV and long-time holding test for 8 h demonstrated at an acceleration 500 kV. The is designed future light sources based on energy-recovery linac consists Cockcroft–Walton generator, segmented cylindrical ceramic insulator, guard-ring electrodes, support-rod electrode, vacuum chamber, pressurized insulating gas tank. insulator the electrodes were utilized prevent any damage from electrons emitted...
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...
We demonstrated a new injection scheme using single pulsed quadrupole magnet (PQM) with no local bump at the Photon Factory Advanced Ring (PF-AR) in High Energy Accelerator Research Organization (KEK). The employs basic property of magnet, that field center is zero, and nonzero elsewhere. amplitude coherent betatron oscillation injected beam effectively reduced by PQM; then, captured into ring without largely affecting already stored beam. In order to investigate performance real beam, we...
High-brightness, high-current electron guns for energy recovery linac light sources and high repetition rate X-ray free-electron lasers require an exit beam of ≥500 keV to reduce space-charge induced emittance growth in the drift space from gun following superconducting accelerator entrance. At Japan Atomic Energy Agency, we have developed a DC photoemission employing segmented insulator mitigate field emission problem, which is major obstacle operation at kV. The first demonstration...
Operational experience of a 500 kV photoemission gun at the compact energy recovery linac (cERL) High Energy Accelerator Research Organization is presented. The gun, developed Japan Atomic Agency, was found to have failures in two out ten-segment ceramic insulator just after installation cERL. had been operated 390 with eight segments until April 2015 and provided 0.9 mA beam. An additional two-segment installed on top existing insulators recover high-voltage performance. then conditioned up...
In this paper, a new SOI BiC-DMOS process based on the 0.25mum CMOS is introduced. and dielectric isolation enables implementation of wide voltage various types lateral power devices. For Nch devices, 40V/60V/ 80V/100V/170V LDMOS 170V/200V IGBT were developed. The drift layers are optimized respectively. helps not only to shrink low class devices such as 40V but also improve SOA characteristics high
A negative electron affinity GaAs photocathode source is characterized by high brightness, quantum efficiency, and a moderate temporal response. The initial emittance depends on the mean transverse energy (MTE) of electrons cathode surface. We evaluated MTE based measurements obtained using waist scan method with three types cathodes: bulk GaAs, thickness-controlled samples active-layer thicknesses 100 1000 nm, GaAs/GaAsP superlattice sample. dependence laser wavelength, thickness active...
The mid-infrared range is an important spectrum where materials exhibit a characteristic response corresponding to their molecular structure. A free-electron laser (FEL) promising candidate for high-power light source with wavelength tunability investigate the nonlinear of materials. Although self-amplification spontaneous emission (SASE) scheme not usually adopted in range, it may have advantages such as layout simplicity, possibility producing single pulse, and scalability short-wavelength...
We have developed a 500-kV, 10-mA photocathode DC gun for energy recovery linac (ERL) light sources. A segmented ceramic insulator with guard rings is employed to improve robustness at high voltage operation, because this structure can prevent field emission electrons from directly striking the surface. recently succeeded in applying 500 kV on ceramics eight hours without any discharge. This testing was performed simple configuration NEG pumps, cathode and anode electrodes mainly study tube...
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.
The recirculation loop of the Compact ERL (cERL) was constructed from July to November in 2013 after commissioning injector . Then entire cERL started December and beam could be accelerated up 20 MeV a short time recir culation ener gy recovery were also achieved without significant loss