Isotope effect in transient electron thermal transport property and its impact on the electron internal transport barrier formation in LHD

In this study, we perform a comprehensive comparison of the transport hysteresis width in deuterium (D) plasmas, hydrogen (H) plasmas, and D-H mixed plasmas. The core focused modulation electron cyclotron resonance heating (MECH) is applied as the heat source perturbation, and the heat flux is evaluated using the energy conservation equation with the measured electron temperature response and the ECH deposition profile calculated by the ray-tracing scheme. Systematic density scan in plasmas with different ion mass reveals that there is no significant isotope effect in their hysteresis width. It is found that plasmas with heavier isotope mass can easily form the electron internal transport barrier. As the hysteresis width is insensitive to the isotope mass, the classical part of the diffusivity is considered to be responsible for the isotope effect in the transport barrier formation

Kidney- and Site-Selective Delivery of 5-Fluorouracil Utilizing the Absorption on the Kidney Surface in Rats

The present study was undertaken to elucidate the kidney- and site-selective delivery of 5-fluorouracil (5-FU) utilizing the absorption on the kidney surface in rats. An experimental system utilizing a cylindrical diffusion cell attached to the right kidney surface was established. After intravenous administration of 5-FU, the concentration of 5-FU in the right and left kidneys was almost the same and was rapidly eliminated. After right kidney surface application of 5-FU, however, the concentration of 5-FU in the right kidney was significantly higher than in the left kidney and other tissues. The 5-FU concentration in four sites of the right kidney after intravenous administration was almost the same. In contrast, 5-FU was site selectively delivered in the kidney after kidney surface application. The blood concentration of 5-FU was low (<1.7 μg/ml) until 120 min after kidney surface application. The maximum blood concentration of 5-FU after kidney surface application was much lower than after intravenous administration

Observation of the inward propagation of spontaneous toroidal flow from the plasma boundary in LHD

Spontaneous generation of toroidal flow from the separatrix and its inward radial propagation in association with the change in the electron temperature gradient have been observed near the plasma boundary in the modulated electron cyclotron heating (MECH) experiment in the Large Helical Device. The observations presented in this paper provide strongly the supports of the hypothesis for the conversion of the poloidal flow to the toroidal one at the plasma peripheral region, exhibiting a clear delay response on MECH in the time derivation of the toroidal flow (????̇ ϕ≡∂????ϕ/∂????) to the poloidal one (????̇ θ≡∂????θ/∂????) at a normalized radius of ρ≈ 0.97. The ratio of order unity for |????̇ ϕ/????̇ θ| during a conversion phase from poloidal flow into toroidal one is consistent with that predicted by a quasi-stationary theoretical model based on the turbulent instability, regardless of its sign and spatial structure. The present work demonstrates a new dynamic response in the plasma momentum transport and represents a significant confirmation of its non-local nature

Effect of Electron Cyclotron Current Drive on the Ion Temperature in the Plasma Core Region of the Large Helical Device

An indirect effect of the electron cyclotron current drive (ECCD) on the ion temperature in the plasma core region was observed in the Large Helical Device. The reference (no ECCD) discharge with a central ion temperature Ti0 of ∼3.0 keV is operated by a standard high ion temperature discharge procedure. To investigate the ECCD effect, a co- or counter-ECCD was applied to the reference discharge, and was turned off immediately before the Ti0 peaked in the reference discharge. In the co-ECCD and counter-ECCD applications, the Ti0 temporarily increased and decreased by ∼0.5 keV from Ti0 in the reference discharge, respectively. The mechanism of this phenomenon is presently unclear, but may be exploited as a practical knob for controlling the central ion temperature