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古株 弘樹*; Yoon, S.*; Lee, H.*; 中嶋 薫*; 松田 誠; 左高 正雄*; 辻本 将彦*; Toulemonde, M.*; 木村 健二*
Nuclear Instruments and Methods in Physics Research B, 460, p.34 - 37, 2019/12
被引用回数：0 パーセンタイル：0.00(Instruments & Instrumentation)Gold and platinum nanoparticles of few-nm size were deposited on amorphous silicon nitride (a-SiN) films. These samples were irradiated with 380 MeV Au ions at grazing incident angles (
=2
-5) to a fluence of ~1
10
ions/cm
. The irradiated samples were observed using transmission electron microscopy (TEM). Ion tracks were clearly observed as long bright lines. Nanoparticles were found to be desorbed from long and narrow regions along the ion tracks. The surface temperature at the thermal spike produced by the ion impact was evaluated from the observed nanoparticle desorption. The observed temperature distribution is qualitatively explained by a one-dimensional two temperature model (1D-TTM) although there are some discrepancies which may be attributed to the surface effects which are not taken into account in 1D-TTM.
Zr
N irradiated by 200 MeV Xe ions高木 聖也; 高野 公秀; 石川 法人
Progress in Nuclear Science and Technology (Internet), 5, p.204 - 207, 2018/00
ZrNやTiNは燃料としての熱的な特性に優れており、マイナーアクチノイド(MA)の核変換用の不活性母材燃料として研究開発が進められている。このような燃料は様々な放射線が存在する環境下で使用されるため、種々の放射線照射下での微細構造安定性を評価することは重要である。特に核分裂片により誘起される高密度電子励起損傷に関する理解は燃料の安全裕度を評価する上で不可欠であるが、窒化物燃料に関してそのような損傷に関する知見はほとんどない。そこで本研究ではZrN不活性母材とMA核変換用窒化物燃料の模擬物質としてDyZrNを用い、高速重イオン照射することで、窒化物燃料に関する高密度電子励起損傷の知見を得ることを目的とした。照射した窒化物試料のX線回折測定から、ZrNおよびDyZrNにおいて照射量の増加に伴い、格子定数が増加することや、回折図形のプロファイルフィッティングから結晶中の格子歪みが増加していることが明らかとなった。
松崎 勝太*; 林 宏明*; 中嶋 薫*; 松田 誠; 左高 正雄*; 辻本 将彦*; Toulemonde, M.*; 木村 健二*
Nuclear Instruments and Methods in Physics Research B, 406(Part B), p.456 - 459, 2017/09
被引用回数：5 パーセンタイル：37.92(Instruments & Instrumentation)Few-nm sized gold, platinum and palladium nanoparticles were deposited on amorphous silicon nitride films. These films were irradiated with 420 MeV Au and 100 MeV Xe ions. Temperature distributions of thermal spikes produced by these ions were evaluated by observing desorption of the nanoparticles from the target surfaces upon ion impact. It was found that the temperature of the thermal spike produced by 420 MeV Au is higher than 100 MeV Xe. The observed temperature of the thermal spike at the entrance surface is slightly lower than that at the exit surface both for 420 MeV Au and 100 MeV Xe ions. These results can be well explained by the inelastic thermal spike model.
中嶋 薫*; 北山 巧*; 林 宏明*; 松田 誠; 左高 正雄*; 辻本 将彦*; Toulemonde, M.*; Bouffard, S.*; 木村 健二*
Scientific Reports (Internet), 5, p.13363_1 - 13363_8, 2015/08
被引用回数：5 パーセンタイル：39.75(Multidisciplinary Sciences)Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.
