Utsunomiya University

About: Utsunomiya University is a education organization based out in Utsunomiya, Japan. It is known for research contribution in the topics: Laser & Holography. The organization has 4139 authors who have published 6812 publications receiving 91975 citations. The organization is also known as: Utsunomiya daigaku.

Improvement of energy-conversion efficiency from laser to proton beam in a laser-foil interaction.

Abstract: Improvement of energy-conversion efficiency from laser to proton beam is demonstrated by particle simulations in a laser-foil interaction. When an intense short-pulse laser illuminates the thin-foil target, the foil electrons are accelerated around the target by the ponderomotive force. The hot electrons generate a strong electric field, which accelerates the foil protons, and the proton beam is generated. In this paper a multihole thin-foil target is proposed in order to increase the energy-conversion efficiency from laser to protons. The multiholes transpiercing the foil target help to enhance the laser-proton energy-conversion efficiency significantly. Particle-in-cell 2.5-dimensional ($x$, $y$, ${v}_{x}$, ${v}_{y}$, ${v}_{z}$) simulations present that the total laser-proton energy-conversion efficiency becomes 9.3% for the multihole target, though the energy-conversion efficiency is 1.5% for a plain thin-foil target. The maximum proton energy is $10.0\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ for the multihole target and is $3.14\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}$ for the plain target. The transpiercing multihole target serves as a new method to increase the energy-conversion efficiency from laser to ions.

Observations of TeV Gamma Ray Flares from Markarian 501 with the Telescope Array Prototype

Abstract: We report the observations of TeV gamma-ray flares from Markarian 501 using the Telescope Array Prototype. The observations were carried out continuously from the end of March to the end of July of 1997. The energy spectrum and the time variation of the gamma-ray intensities are shown. The intensity has been changed by an order of magnitude in this period, and the possible quasi-periodic oscillation of 12.7 days were discovered.

Effects of pH and Ferrous Ion on the Degradation of Glucosinolates by Myrosinase

Abstract: During the enzymatic degradation of sinigrin, the release of glucose and the formation of allyl isothiocyanate via subsequent cleavage of the aglucon were studied in the presence or absence of ferrous ion over a pH range of 3.5 ~ 7.5. The liberation of glucose increased linearly with the time of enzymatic cleavage of sinigrin for the first 20 min at the pHs used, and no inhibition of glucose liberation was caused by ferrous ion at the concentration tried.On the other hand, the effects of ferrous ion on the formation of isothiocyanate changed greatly with changes of pH of the reaction medium. At pH 4.5 and 5.5, formation of isothiocyanate was strongly inhibited by ferrous ion, while such an effect of ferrous ion was notably depressed at pH 6.5 and disappeared at pH 7.5. These results were also confirmed by gas chromatographic analysis of the volatile cleavage products of the glucosinolates prepared from the seed meal of hakuran (an artificial variety of Brassica napus). From these results, it was suggested...