定常プラズマ照射下の液体金属中での水素透過に関する研究

Hydrogen Plasma-driven Permeation (PDP) experiments through two different liquid metal membranes: lithium and GaInSn have been conducted in the temperature range from 300 to 500 ◦C. A technique employing a mesh sheet to hold a liquid metal for PDP has been utilized for the first time. It has been found that PDP is surface recombination limited for lithium and is diffusion limited for GaInSn. Hydrogen surface recombination coefficients for liquid lithium and hydrogen diffusivity in GaInSn have been obtained respectively

Evaluation of tritium production rate in a blanket mock-up using a compact fusion neutron source

We report a neutronics study of a blanket mock-up using a discharge-type compact fusion neutron source. Deuterium–deuterium fusion neutrons were irradiated to the mock-ups composed of tritium breeder and neutron reflector/moderator. The tritium production rate (TPR) per source neutron was measured by a single-crystal diamond detector with a 6Li-enriched lithium fluoride film convertor after the calibration process. Despite the low neutron yield, energetic alpha and triton particles via 6Li(n, t)α neutron capture as well as 12C via elastic scattering were successfully detected by the SDD with high signal to noise ratios. The TPRs were experimentally evaluated with errors of 8.4%–8.5% at the 1σ level at the positions with high thermal neutron fluxes where the errors were dominantly introduced by uncertainties in the monitoring of the neutron production rate. The calculated to experimental (C/E) values of TPR were evaluated to be 0.91–1.27 (FENDL-2.1) and 0.94–1.28 (FENDL-3.1). As the neutron source can generate 14 MeV neutrons using a mixed gas of deuterium and tritium, this approach provides more opportunities for blanket neutronics experiments

Novel repressor regulates insulin sensitivity through interaction with Foxo1

This study characterizes a novel Foxo1 CoRepressor (FCoR) that regulates insulin sensitivity and energy metabolism as revealed by whole-body knockout. As target of PKA phosphorylation, FCoR modulates Foxo's acetylation known to control Foxo's biological activity

A study on hydrogen isotopes transport in a liquid metal GaInSn by plasma-driven permeation method

The application of liquid metals such as gallium, tin and lithium as plasma-facing materials is a potential means to resolve the technical issues associated with power exhausting and particle handing in magnetic fusion devices. GaInSn alloy with melting point of 10.5°C, is employed as a modeling material to explore the plasma-driven permeation (PDP) method to study the hydrogen isotopes (hydrogen and deuterium) transport parameters in a liquid metal. Static liquid GaInSn membranes sitting on a mesh sheet are exposed to hydrogen/deuterium plasmas in the linear plasma device VEHICLE-1 with the temperature range of 280–496°C. Hydrogen/deuterium diffusivity are obtained by fitting the time evolutions of permeation fluxes. The dynamic hydrogen/deuterium retention in the liquid GaInSn are found to be low (∼1015D/cm3), which are consistent with the thermal desorption spectroscopy (TDS) measurement following plasma exposure. The hydrogen and deuterium transport parameters are found to be close to each other. Keywords: Liquid metal, Plasma-driven permeation, Diffusivity, Recombination coefficient, Retentio

Hydrogen Gas-Driven Permeation through F82H Steel Coated with Vacuum Plasma-Sprayed Tungsten

The subject of hydrogen isotopes transport through tungsten coated reduced activation ferritic steels such as F82H has attracted increasing interest in the fusion engineering research community. This paper reports on laboratory-scale studies that have been done to assess the hydrogen permeation properties of vacuum plasma-sprayed tungsten (VPS-W) coatings at the temperature range of 200 - 500 °C. W coatings with thicknesses of 46 μm and 90 μm have been investigated. It has been found that the observed permeation rates through composite VPS-W/F82H specimen are reduced to ∼7% compared to that of pure F82 H. VPS-W coating is porous and has an open system of connected pores, which density is evaluated to be ∼7%. The main effect of the W coating on hydrogen permeation is to reduce the incoming flux at the W/F82H interface owing to pore diffusion in the coating and to reduce the effective surface area for hydrogen dissolution in the substrate

Characterization of an ultra-compact neutron source based on an IEC fusion

Our group is developing an ultra-compact neutron source based on inertial electrostatic confinement (IEC) fusiondevice for various applications at Kyoto University. This IEC device is configured from a titanium anode and amolybdenum cathode with diameters of 17 and 6 cm, respectively. A high-intensity neutron source operated in astable pulse shape is mandatory to increase the system’s reliability. Applying a higher voltage is a straightforwardway to increase the neutron yield from the system. However, a contradiction between the increase of theapplied voltage and the reduction of the system size limits such a proposal. A three-stage feedthrough system isemployed in the developed compact IEC to address this contradiction. A feedback control system was developedand applied to the input and output parameters, such as the applied voltage and the neutron yield, to increase itsstability in long-term operation. Characterization of the developed system was performed by scanning theneutron yield as a function of applied voltage and cathode current. To date, a maximum neutron yield of 9.2 ×107n⋅s–1 at 6.4 kW (80 kV and 80 mA) has been obtained. A study of the feasibility of using the IEC system forneutron radiography was performed. Preliminary analysis of the resulting images showed there was goodcontrast between the sample and the background. The results suggest that optimization of the experimentalparameters is needed to perform higher accuracy neutron radiography

Hydrogen Solubility of the Molten Salt FLiNaK Mixed with Nano-Ti Powder

The hydrogen-release behavior of the molten salt FLiNaK containing directly synthesized 0.1 wt% nano-Ti powder was investigated. Hydrogen release was faster at higher temperatures, and the volume of released hydrogen from FLiNaK was significantly higher than that from pure FLiNaK. However, the ratio of released H/Ti in FLiNaK was smaller than that in μm-Ti powder