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.

Improvement of SiO2/4H-SiC Interface Using High-Temperature Hydrogen Annealing at Low Pressure and Vacuum Annealing

Abstract: The influences of high-temperature H2 annealing at low pressure (8.5×102 Pa at 1273 K) and vacuum (1× 10-4 Pa at 1273 K) annealing on capacitance-voltage (C-V) characteristics of 4H-SiC MOS structures have been investigated. H2 annealing more effectively reduced the flat band voltage shift of the 4H-SiC MOS structure than vacuum annealing. The interface state density of the 4H-SiC MOS structure after H2 annealing at 1273 K was reduced to approximately one-fifth that of the sample without H2 annealing. Secondary ion mass spectroscopy (SIMS) revealed that hydrogen accumulated at the SiO2/4H-SiC interface, and its density increased with H2 annealing temperature.

TIARA electrostatic accelerators for multiple ion beam application

Abstract: A unique electrostatic accelerators facility has been constructed mainly for application of multiple beam and microbeam to materials science research at JAERI Takasaki. The facility consists of a 3 MV single-ended accelerator with an extremely high voltage-stability of ± 1 × 10 −5 , a 3 MV tandem accelerator and a 0.4 MV ion implanter, which cover various ion particles in an energy range of 10 keV to 20 MeV. A voltage ripple of ± 1 × 10 −5 (60 V pp ) at 3 MV has been achieved for the single-ended machine. The performance of accelerators, beam lines and their applications to various research activities are outlined.

LET dependence of lethality in Arabidopsis thaliana irradiated by heavy ions.

Abstract: To clarify the effect of heavy ions in plants, dry seeds of Arabidopsis were irradiated with carbon, neon, and argon ions with various linear energy transfer (LET) values. The relative biological effectiveness (RBE) for lethality peaked at LET values over 350 keV/µm for neon and argon ions. This LET giving the peak RBE was higher than the LET of 100–200 keV/µm which was reported to have a maximum RBE for other types of cells, such as mammalian cells. Furthermore, sterility showed a higher RBE at an LET of 354 keV/µm with neon ions than that at an LET of 113 keV/µm with carbon ions. Lethality and sterility are both considered to be caused by damage to DNA. The results indicate that the LET having a maximum of RBE for lethality is higher in Arabidopsis seeds than in other unicellular systems. The most likely explanation for this shift of LET is that the DNA in dry seeds has a different chemical environment and/or hydration state than the DNA in cells in culture.