A5068098969- Magnetic confinement fusion research
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Graphite, nuclear technology, radiation studies
- Radiation Detection and Scintillator Technologies
- Nuclear and radioactivity studies
- Nuclear Materials and Properties
- Boron Compounds in Chemistry
- Grouting, Rheology, and Soil Mechanics
- Drilling and Well Engineering
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Shielding Materials Analysis
- Geotechnical and Mining Engineering
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
National Institutes for Quantum Science and Technology
2017-2020
Japan Atomic Energy Agency
2006-2016
A soft-type neutron-shielding resin has been developed by improving an existing hard-type neutronshielding material using the epoxy-based as additional shielding material. flexible heat-resistant developed, which consists of a new polymer-based with boron. The neutron performance 252Cf source is almost same that polyethylene. outgases H, H2, NH4, H2O, CO, O2, C4H10, and CO2 from have measured at high temperature (up to 250°C) thermal desorption spectroscopy methods. newly will be applied...
A line-integrated neutron emission profile is routinely measured using the radial collimator system in JT-60U tokamak. Stilbene neuron detectors (SNDs), which combine a stilbene organic crystal scintillation detector (SD) with an analog neutron-gamma pulse shape discrimination (PSD) circuit, have been used to measure collimated flux. Although SND has many advantages as detector, maximum count rate limited up ∼1×105counts∕s due PSD circuit. To overcome this issue, digital signal processing...
Flexible heat-resistant neutron and gamma-ray shielding resins have been successfully developed through the use of a polymer resin.The production process involves new mixing technique resin materials for absorber/gamma-ray attenuation using cold-setting method.The allows easy onsite fabrication.The are B 4 C powder shield, Colemanite neutron/gamma-ray shield FeW respectively.We assessed basic property penetration performance carried out irradiation test Japan Research Reactor 3. Gamma-ray...
A 3D neutron and photon transport analysis by Monte Carlo code system PHITS (Particle Heavy Ion Transport System) has been performed for superconducting tokamak fusion device such as JT-60 Super Advanced (JT-60SA).It is possible to make use of in the port streaming around devices device, duct building where installed, sky shine site boundary.The makes it clear that shielding performance with cryostat improved graphical results.From standpoint streaming, necessary estimate neutronics device.
A complete 3D neutronic analysis by PHITS (Particle and Heavy Ion Transport code System) has been performed for fusion tokamaku devices such as JT-60U device JT-60 Superconducting tokamak (JT-60 Super Advanced).The mono-energetic neutrons (E n =2.45 MeV) of the DD are used neutron source in analysis.The visual flux distribution estimation port streaming dose rate around calculated PHITS.The makes it clear that effect superconducting with cryostat is crucial spectrum results agree MCNP-4C2 results.
AbstractAbstractThree kinds of unique high-heat-resistant neutron shielding resins have been developed. One is an excellent resin in terms light weight. Another a high-neutron-shielding-performance with heat-proof temperature 200°C. The third improved up to 300°C. performance the was carried out using 252Cf source. results show that 200°C better than temperatures And, 300°C almost same as polyethylene. It can be concluded attractive material high-temperature environment.
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> At Japan Atomic Energy Agency (JAEA), the JT-60 is planned to be modified a full-superconducting tokamak referred as Super Advanced (JT-60SA) one of JA-EU broader approach projects. In JT-60SA, magnet system with 1400 ton consists 18 toroidal field (TF) coils, 4 stacks central solenoid (CS) and 7 plasma equilibrium (EF) coils. The TF coil using NbTi cable-in-conduit (CIC) conductor has maximum...
We have conducted calibrations of a microfission chamber, which was installed between the vacuum vessel and toroidal field coils, by both Cf-252 neutron source real deuterium plasmas in JT-60U. The detector employs pulse counting Campbell (mean square voltage) modes electronics to cover wide dynamic range strength. were calibrated plasmas, respectively. Point efficiencies, counts per from point at single angle, measured for 27 locations scan. efficiencies influenced various components such...
The inhomogeneous poloidal magnetic field of tokamak device, which is called error field, has to be reduced because the degrades plasma performance. There are 18 sets EFC coils installed inside vacuum vessel for JT-60SA compensate field. conceptual design been completed. water-cooled hollow copper conductor was selected reduce size since available space small. outer and diameter cooling channel were optimized in considering hydraulic thermal characteristics. validated by testing a mock-up...
This paper describes diagnostics for transport analysis of energetic ions in JT-60U. Line integrated neutron emission profiles are measured using Stilbene detectors, which installed as a profile monitor. The flux and energy distribution charge exchange neutral particles natural diamond detector (NDD). These measurements the presence bursting instabilities frequency range Alfvén Eigenmode induced by negative-ion-based beam injection, called Abrupt Large-amplitude Events, indicate that...
The radioactivities on the materials of JT-60U fusion device, which decommissioning is underway toward upgraded superconducting tokamak machine, have been evaluated by calculation and measurements specimens structure components. In induced activities those materials, highest activation material was stainless steel. essential nuclide ^<60>Co in steels. steel 316 about 35 tons constitutes base interiorities as a first wall vacuum vessel JT-60U. For management radioactive evaluation for steels...
A soft-type neutron-shielding resin has been developed by improving an existing hard-type neutronshielding material using the epoxy-based as additional shielding material. flexible heat-resistant developed, which consists of a new polymer-based with boron. The neutron performance 252Cf source is almost same that polyethylene. outgases H, H2, NH4, H2O, CO, O2, C4H10, and CO2 from have measured at high temperature (up to 250°C) thermal desorption spectroscopy methods. newly will be applied...
Materials and structures of a collimator for new neutron emission profile monitor in JT-60SA are examined through Monte Carlo simulations using the N-Particle transport code. First, shielding properties various material combinations compared order to determine combination with high performances against both neutrons gamma-rays. It is found that consisting borated polyethylene lead has performance neutrons. Moreover, gamma-rays obtained when pipe radial thickness 0.01 m inserted into...
In this study, a comparison between simulations using the Particle and Heavy Ion Transport code System (PHITS) activated material analysis of JT-60U have been performed. Neutron transport has simulated Monte Carlo method PHITS to determine neutron fluency at irradiation position. The complemented by foil-activation technique. preliminary accuracy assessment these confirmed comparing reaction rates gold, cobalt, nickel foil activation. simulation results consistent with measured rate each near device.
The upgrade of JT-60U to the superconducting tokamak "JT-60SA" has been carried out as a combined project JAEA's program for national use and Satellite Tokamak Program in collaboration with EU Japan fusion communities. torus was dismantled so install new JT-60SA at same position hall. used deuterium 18 years, neutron yield reached about 1.5×1020 (n) total. dismantling first decommissioning experience device radioactivity Japan. intended demonstrate technologies work activities, acquire data...
In the present study, a comparison between simulations using PHITS code and activated material analysis of JT-60U have been performed. Neutron transport has simulated Monte Carlo methods to determine neutron fluency at irradiation position. The complemented by foil-activation technique. preliminary accuracy assessment these confirmed comparing reaction rates gold, cobalt, nickel foil activation. simulation results consisted with measured rate each foils near device.