Japan Atomic Energy Agency

About: Japan Atomic Energy Agency is a government organization based out in Tōkai-mura, Japan. It is known for research contribution in the topics: Neutron & Laser. The organization has 7151 authors who have published 17791 publications receiving 259118 citations. The organization is also known as: JAEA & Nihon genshiryoku kenkyū kaihatsu kikō.

Improving cesium removal to clean-up the contaminated water using modified conjugate material

Abstract: Crown ether based conjugate material was enabling the high functionality for stable complexation mechanism with cesium (Cs) and attracted the scientific community for potential real radioactive contaminated water treatment. This study was focused on ligand anchored conjugate material for radioactive Cs disposal based on adsorption techniques from nuclear liquid waste in Fukushima with high selectivity. A macrocyclic ligand of acetyl dibenzo-20-crown-6-ethers (AcDB20C6) was synthesized and directly embedded onto mesoporous inorganic silica. The Cs adsorption behavior was carried out with batch equilibrium techniques. The affecting experimental parameters such as solution pH, contact time, initial Cs concentration and competitive adsorption of Na and K ion concentrations were measured and optimized systematically. The sensitive pH range for high Cs removal was with broad range of 5.5–9.0, and the maximum adsorption capacity was 65.06 mg/g by the material at pH 7.0. The results clarified that conjugate material was high selectivity towards Cs even in the presence of a high level of Na and K ions rather than inorganic adsorbent because of the possible Cs-π interaction of the benzene ring from the crown ether ligand. The material was successfully investigated for radioactive Cs disposal for the potential treatment in Fukushima in the connection of in nuclear contaminated water treatment. The adsorbed Cs was desorbed with the eluent of 0.20 M HCl and then simultaneously regenerated at the same into the initial form for the next disposal operation after washing with water. The conjugate material was kept high functionality even in several cycles during adsorption–elution–regeneration processes. Then the proposed material could be used as promising material for selective radioactive Cs disposal from contaminated water in Fukushima, Japan.

Evolution of shell structure in exotic nuclei

Abstract: The atomic nucleus is a quantum many-body system whose constituent nucleons (protons and neutrons) are subject to complex nucleon-nucleon interactions that include spin- and isospin-dependent components. For stable nuclei, several decades ago, emerging seemingly regular patterns in some observables could already be described successfully within a shell-model picture that results in particularly stable nuclei at certain magic fillings of the shells with protons and/or neutrons: N, Z=8, 20, 28, 50, 82, 126. However, in short-lived, so-called exotic nuclei or rare isotopes, characterized by a large N/Z asymmetry and located far from the valley of β stability on the nuclear chart, these magic numbers, viewed through observables, were shown to change. These changes in the regime of exotic nuclei offer an unprecedented view at the roles of the various components of the nuclear force when theoretical descriptions are confronted with experimental data on exotic nuclei where certain effects are enhanced. This article reviews the driving forces behind shell evolution from a theoretical point of view and connects this to experimental signatures.