A5074758608- Superconducting Materials and Applications
- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Particle Accelerators and Free-Electron Lasers
- Muon and positron interactions and applications
- Particle physics theoretical and experimental studies
- Advanced MRI Techniques and Applications
- Atomic and Subatomic Physics Research
- Ionosphere and magnetosphere dynamics
- Magnetic Field Sensors Techniques
- Plasma Diagnostics and Applications
- Atomic and Molecular Physics
- Advanced NMR Techniques and Applications
- Magnetic Properties and Applications
- Non-Destructive Testing Techniques
- Physics of Superconductivity and Magnetism
- Laser-Plasma Interactions and Diagnostics
- Astronomical Observations and Instrumentation
- Geophysics and Sensor Technology
- Magneto-Optical Properties and Applications
- Electrical and Bioimpedance Tomography
- Electrostatic Discharge in Electronics
- Nuclear reactor physics and engineering
- NMR spectroscopy and applications
High Energy Accelerator Research Organization
2018-2024
Hitachi (Japan)
2010-2019
Advanced Science Research Center
1992-2004
Ibaraki University
1997
Hitachi (United Kingdom)
1996
Japan Atomic Energy Agency
1984-1989
This paper introduces a new approach to measure the muon magnetic moment anomaly |$a_{\mu} = (g-2)/2$| and electric dipole (EDM) |$d_{\mu}$| at J-PARC facility. The goal of our experiment is |$a_{\mu}$| using an independent method with factor 10 lower momentum, 20 smaller diameter storage-ring solenoid compared previous ongoing |$g-2$| experiments unprecedented quality storage field. Additional significant differences from present experimental include 1000 transverse emittance beam...
Various superconducting detector solenoids for particle physics have been developed in the world. The key technology is aluminum-stabilized conductor almost all magnets experiments. With progress of conductor, coil fabrication has progressed as well, such inner winding technique, indirect cooling, transparent vacuum vessel, quench protection scheme using pure aluminum strips and so on. design study future big projects Japan Europe, that is, ILC, FCC CLIC, based on technologies established...
At the J-PARC Muon Science Facility (MUSE), MuSEUM collaboration is now performing new precision measurements of ground state hyperfine structure (HFS) both muonium and muonic helium atoms. High-precision ground-state HFS are recognized as one most sensitive tools for testing bound-state quantum electrodynamics theory to precisely probe standard model determine fundamental constants positive muon magnetic moment mass. The same technique can also be employed measure HFS, obtain negative mass,...
A centrifuge injector that repetitively fires 1.3 mm deuterium pellets (1 torr⋅L per pellet) at a rate of 32 second was used to build up and maintain Doublet III 2.4 MW neutral-beam-heated limiter discharge line-averaged density 1 × 1014 cm−3. When compared conventional gas-fuelled plasma similar density, the pellet-fuelled characterized by factor-of-three reduction in edge neutral recycling, centrally peaked profile, 70% increase global energy confinement, tenfold fusion reaction rate.
In the JFT-2M tokamak, application of low activation ferritic steels to plasmas has been investigated (the so-called Advanced Material Tokamak Experiment (AMTEX) programme). first stage, toroidal field ripple reduction was examined by steel boards (FBs) inserted between coils and vacuum vessel. It is demonstrated that FB insertion reduced losses fast ions produced tangential co-NBI. By optimizing thickness, such fundamental mode minimized 0.07% at shoulder inside wall, trapped loss an almost...
High precision measurements of the ground state hyperfine structure (HFS) muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants muon magnetic moment and mass, searches new physics. Muonium most suitable system to test QED because both theoretical experimental values can be precisely determined. Previous were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At J-PARC Muon Science...
Muonium spectroscopy experiment using microwave and J-PARC E34 (J-PARC muon g-2/EDM) experiments aim to measure the hyperfine structure of muonium anomalous magnetic moment muon, respectively. Both require homogeneous fields better than 1 ppm. Therefore, we developed a standard probe calibrate field measurement probes, with resolution 1.92±0.18 ppb. Moreover, shift nuclear resonance frequency was also evaluated, total uncertainty is ±17.7
Magnetic field shimming using low saturation magnetization material was tested to realize spatial magnetic homogeneity of less than 1 ppm. The moment per unit mass were measured for three candidates, that is, Nickel, fluid and putty, it verified those have moments suitable precise below test performed MRI magnet MuSEUM experiment at 1.2 T with iron plates, Ni thin plates putty. conducted employing the two step scheme, could be reached 0.29 ppm peak-to-peak (ppm <inline-formula...
We present a novel non-stochastic method for optimizing the shapes of ferromagnetic materials to generate target static magnetic field. A magnetizing current corresponding an error field is calculated as inverse problem and then replaced with equivalent material. Iteration this process leads almost zero. It should be noted that initial condition material shape critical convergence. Consequently, we propose combined method: generated stochastic optimization algorithm, updated using explicit...
A design technique to calculate winding patterns of active shield gradient coils has been developed with the tool using current potential and singular value decomposition (SVD) (DUCAS), which is a computer code construct sheet distributions on arbitrary surfaces (CP), triangular finite elements, regularization truncated SVD. The DUCAS calculates currents carrying (CCSs) CCS1 for main coil CCS2 coil, so as reconstruct field magnetic shielding iteratively. iterative calculation converged in...
This paper describes a new method to determine the current and coil block placements with good homogeneity for magnetic resonance imaging (MRI) magnets, discusses relationships between homogeneity, using regularization of truncated singular value decomposition (SVD). In first step, main (MC) is modeled as filament loop currents (FLCs) on solenoid shield (SC) by blocks. The FLCs are determined so get homogeneous field superposition eigenmodes obtained SVD. second replaced MC findings follows....
A new shimming calculation method for a static magnetic field in cylindrical magnets has been developed and the feasibility was confirmed by test shimming. The is based on truncated singular value decomposition regularization to solve linear system of equations with response matrix from iron piece volumes shim-pockets distribution. Singular obtains eigenmodes which are numbered descending sequence singular. Low-ordered (large value) chosen summed get placements, considering number main coil...
DUCAS is a computer code using an arbitrary magnetic field distribution as input and producing sheet current output. The was improved for application to the resonance imaging (MRI) gradient coil (GC) design. computes potential (CP) distribution, conductors are placed along contours, which flow lines. An algorithm with weights on node CPs initial described use DUCAS. obtains CP by summing singular value decomposition (SVD) eigendistributions distribution. modify eigendistributions. used get...
A magnetic field design for a superconducting (SC) wiggler system, which has been installed in the Saga light source storage ring, was described. The is three-pole type, consisting of 4.0-T SC center magnet and two normal-conducting side magnets; thus, each pole forms magnet. Since consists isolated magnets, reduction first integral important from viewpoint suppression orbit displacement. For this purpose, designed to have separated iron core with clamps no transverse return yoke. This...
To examine the effects of ferritic steel on error field, ripple reduction and plasma properties (especially for improved confinements), Advanced Material Tokamak EXperiment (AMTEX) is planned JFT-2M. The AMTEX program consists test toroidal field with inserts that compatibility between tokamak plasma. reduce fast ion losses due to ripple, amplitude its mode number have be reduced. guideline design in (δ) by inserting Ferritic Boards (FB) as follows; wider thicker FB should positioned far...
A hybrid three-pole wiggler for generating hard X-rays in the range 4-40 keV was designed 1.4-GeV storage ring of a synchrotron radiation facility, i.e., Saga Light Source. The consists superconducting main pole with peak field 4 T and two normal-conducting side poles fields 1 T. were used to reduce heat load on cryogenic system wiggler. cryogen-free ensure long-term operational stability system. coil iron are cooled by Gifford-McMahon cryocooler via mechanical contact. To suppress first...
To develop a new shimming calculation method, which can calculate iron piece placements rapidly to make the magnetic field homogeneous at intended homogeneity and then working time short.The yields moment (MM) distribution, is calculated by truncated singular value decomposition (SVD) from measured field. The MM distribution described superposition of eigenmodes obtained SVD response matrix distributions fields view (FOV). regulated truncation number superposed eigenmodes. moments are...
This paper describes an improved method to determine coil block (CB) placements with good homogeneities for magnetic resonance imaging magnets. Each magnet has a main (MC) strong fields in volume of interest and shield (SC) make the weak outside magnet. The CB are done three steps at every step, SC moments tuned. In step 1, approximate axially distributed circular filament loop currents. According distribution, rough CBs MC. 2, cross-sectional shapes positions optimized get homogeneity real...
A new technique to calculate the optimum modular coil winding path for a helical plasma confinement system has been developed. The is based on current potential an arbitrary surface with finite elements and singular value decomposition (SVD). No function assumed distribution, then, little error occurs from modeling. SVD applied response matrix magnetic field surface. distribution constructed eigen obtained through so that normal component small. determined along flow lines or equi-contour of...