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.

Direct simulation of the time-dependent Ginzburg-Landau equation for type-II superconducting thin film: Vortex dynamics and V-I characteristics.

Abstract: We obtain the V-I characteristics of the type-II superconductors for thin film by numerically solving the time-dependent Ginzburg-Landau equation coupled with the Maxwell equation in the two-dimensional region. We observe a sequence of pulses in the time development of the measured voltage, leading to intense energy dissipation in superconductors. We show that these voltage pulses are related to the penetration and annihilation of vortices at the boundary and the annihilation of two merging vortices with opposite sign.

Graft polymerization of acrylic acid onto polyethylene film by preirradiation method. I. Effects of preirradiation dose, monomer concentration, reaction temperature, and film thickness

Abstract: Low- and high-density polyethylenes were irradiated by electron beams with dose of 2 to 50 Mrad and then immersed in aqueous solution of acrylic acid (monomer concentration from 30 to 100 wt %) for 10 min to 5h at a temperature of 25 to 40/sup 0/C. The degree of grafting increases with time and levels off. High density polyethylene shows lower grafting rate and higher final % grafting in compared with low-density polyethylene. Both grafting rate and final % grafting increase with total dose of preirradiation, but show some saturation at high doses. The highest grafting rate was observed at 60 wt % of monomer concentration where the grafted polyethylene swells to the largest extent in the monomer mixture. Apparent activation energies for the grafting are 19.6 and 27.3 kcal/mol for low- and high-density polyethylenes, respectively, reflecting the process of monomer diffusion in the film. Grafting rate decreases with increasing film thickness. Graft polymerization starts on the surface of the film and proceeds to the inner part with monomer diffusion through the grafted layer.

Characterization of a 40–90 MeV 7Li(p,n) neutron source at TIARA using a proton recoil telescope and a TOF method

Abstract: The intensity and energy spectra of a quasi-monoenergetic 7 Li(p,n) neutron source at TIARA of Japan Atomic Energy Research Institute (JAERI) have been measured for eight incident proton energies between 43 and 87 MeV, using a proton recoil telescope (PRT) of annular geometry and a time-of-flight (TOF) method employing organic scintillators (BC501A, NE213) calibrated prior to the experiment. By combining the two data, we deduced energy spectra of the source neutrons absolutely down to a few MeV, and the cross section of the peak neutron production reaction, 7 Li ( p , n 0,1 ) 7 Be . The continuum component of the energy spectrum in the source proved to be described consistently by assuming a three-body phase-space distribution corresponding to the 7 Li ( p , n 3 He )α reaction as a main component. The annular PRT achieved a good compromise between energy resolution and detection efficiency with a good signal-to-noise ratio.

Disruption of the AtREV3 Gene Causes Hypersensitivity to Ultraviolet B Light and γ-Rays in Arabidopsis: Implication of the Presence of a Translesion Synthesis Mechanism in Plants

Abstract: To investigate UV light response mechanisms in higher plants, we isolated a UV light–sensitive mutant, rev3-1, in Arabidopsis. The root growth of rev3-1 was inhibited after UV-B irradiation under both light and dark conditions. We found that chromosome 1 of rev3-1 was broken at a minimum of three points, causing chromosome inversion and translocation. A gene disrupted by this rearrangement encoded the catalytic subunit of DNA polymerase ζ (AtREV3), which is thought to be involved in translesion synthesis. The rev3-1 seedlings also were sensitive to γ-rays and mitomycin C, which are known to inhibit DNA replication. Incorporation of bromodeoxyuridine after UV-B irradiation was less in rev3-1 than in the wild type. These results indicate that UV light–damaged DNA interrupted DNA replication in the rev3-1 mutant, leading to the inhibition of cell division and root elongation.