Japan Atomic Energy Research Institute

About: Japan Atomic Energy Research Institute is a based out in . It is known for research contribution in the topics: Neutron & Irradiation. The organization has 7707 authors who have published 14471 publications receiving 207688 citations.

Adsorption of metal ions by carboxymethylchitin and carboxymethylchitosan hydrogels

Abstract: Radiation cross-linking of CM-chitin and CM-chitosan has been investigated. Such parameters of radiation cross-linking as gelation doses, cross-linking and degradation radiation yields and ratios of scission to cross-linking has been determined for both polymers. The absorption ability of various metal ions into EB-radiation cross-linked carboxymethylchitin and carboxymethylchitosan has been investigated. The highest adsorption of scandium and gold has been obtained for carboxymethylchitin (CMCht) and carboxymethylchitosan (CMChts), respectively. Kinetic studies showed that adsorption of most of the metal ions occur in a relatively short period of time (2 h). Detail investigation of adsorption of gold ions has been carried out for both hydrogels. The maximum uptake of Au cations, based on Langmuir equation was determined to be 37.59 for CM-chitosan and 11.86 for CM-chitin. Both hydrogels indicate favorable adsorption of gold cations.

Stabilization effect of early ECCD on a neoclassical tearing mode in the JT-60U tokamak

Abstract: Stabilization of an m = 3/n = 2 neoclassical tearing mode (NTM) has been studied experimentally by applying a local electron cyclotron current drive (ECCD) in the JT-60U tokamak. The EC power is injected before the mode onset, and its effect is compared with the ECCD applied at the saturation phase. The experimental results show that the ECCD applied at the growth phase is more effective than that applied at the saturation phase. The necessary EC power for the suppression is reduced and the mode onset is delayed, indicating the hysterisis characteristics of the NTM on the ECCD stabilization. The dependence on the EC power and injection angle is also shown.

3D computer simulation of the primary electron orbits in a magnetic multipole plasma source

Abstract: Performance characteristics of the magnetic multipole plasma source depend strongly on the structure of the line‐cusp magnetic fields and the behavior of the primary electrons. In order to design and improve the plasma source efficiently, we developed a computer code which can simulate primary electron orbits in the three‐dimensional magnetic field generated in the source. Using this code, we compared the orbits of the primary electrons in the arc discharges with and without the mode‐flip phenomenon. The result indicates that the trapping of the primary electrons in a local magnetic mirror fields causes the mode flip due to the reduction of the effective anode area. Trapping also degrades the spatial uniformity of the source plasma density, due to local arc discharge. The structure of the magnetic field can be optimized so that the primary electrons fill the center region of the source. The 3D simulation of the electron orbits turned out to be effective and useful in designing a multipole source.