The impact-induced deposition of Al13 clusters with icosahedral structure on Ni(0 0 1) surface was studied by molecular dynamics (MD) simulation using Finnis–Sinclair potentials. The incident kinetic energy (Ein) ranged from 0.01 to 30 eV per atom. The structural and dynamical properties of Al clusters on Ni surfaces were found to be strongly dependent on the impact energy. At much lower energy, the Al cluster deposited on the surface as a bulk molecule. However, the original icosahedral structure was transformed to the fcc-like one due to the interaction and the structure mismatch between the Al cluster and Ni surface. With increasing the impinging energy, the cluster was deformed severely when it contacted the substrate, and then broken up due to dense collision cascade. The cluster atoms spread on the surface at last. When the impact energy was higher than 11 eV, the defects, such as Al substitutions and Ni ejections, were observed. The simulation indicated that there exists an optimum energy range, which is suitable for Al epitaxial growth in layer by layer. In addition, at higher impinging energy, the atomic exchange between Al and Ni atoms will be favourable to surface alloying.

Nuclear instruments and methods in physics research section B : beam interactions with materials and atoms

Associate Editors: Hiroshi Akie, Japan Atomic Energy Agency, Japan Miyuki Akiba, Toshiba Corporation, Japan Mariko Atarashi-Andoh, Japan Atomic Energy Agency, Japan Go Chiba, Hokkaido University, Japan Kenji Dohi, Central Research Institute of Electric Power Industry, Japan Tomohiro Endo, Nagoya University, Japan Kouji Hiraiwa, Toshiba Corporation, Japan Eiichi Hori,Mitsubishi Heavy Industries Ltd., Japan Tsutomu Ikeno, Nuclear Fuel Industries Ltd., Japan Tomoaki Inamura,Central Research Institute of Electric Power Industry, Japan Yasunori Iwai, Japan Atomic Energy Agency, Japan Takanori Kameyama, Tokai University, Japan Mamoru Kamoshida,Hitachi, Ltd., Hitachi Research Laboratory, Japan Yuko Kani, Hitachi, Ltd., Hitachi Research Laboratory, Japan Masato Kato, Japan Atomic Energy Agency, Japan Tatsuya Kato, Toshiba Corporation, Japan Hiroshi Kimura, Public Outreach, NPO, Japan Atsushi Kimura, Japan Atomic Energy Agency, Japan Akira Kitamura, Japan Atomic Energy Agency, Japan Kazuaki Kitou, Hitachi, Ltd, Hitachi Research Laboratory, Japan Akira Kirishima, IMRAM, Tohoku University, Japan Mitsuhiro Kodama, Nippon Nuclear Fuel Development Co., Ltd., Japan Shinya Kosaka,Mitsubishi Heavy Industries Ltd., Japan Masaki Kurata, Japan Atomic Energy Agency, Japan Ken Kurosaki, Osaka University, Japan Daekjung Lee, Ulsan National Institute of Science and Technology, Korea Wei Liu, Japan Atomic Energy Agency, Japan

日本原子力学会誌および欧文論文誌(Journal of Nuclear Science and Technology)の改革案

Nuclear Data Sheets for A = 26

The search for neutrinoless double-beta decay $(0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta})$ requires extremely low background and a good understanding of their sources and their influence on the rate in the region of parameter space relevant to the $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ signal. We report on studies of various $\ensuremath{\beta}$ and $\ensuremath{\gamma}$ backgrounds in the liquid-xenon-based EXO-$2000\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ experiment. With this work we try to better understand the location and strength of specific background sources and compare the conclusions to radioassay results taken before and during detector construction. Finally, we discuss the implications of these studies for EXO-200 as well as for the next-generation, tonne-scale nEXO detector.

/pdf/investigation-of-radioactivity-induced-backgrounds-in-exo-4auhi8cpt2.pdf

Investigation of radioactivity-induced backgrounds in EXO-200

Nuclear recoil backgrounds are one of the most dangerous backgrounds for many dark matter experiments. A primary source of nuclear recoils is radiogenic neutrons produced in the detector material itself. These neutrons result from fission and ( α , n ) reactions originating from uranium and thorium contamination. In this paper, we discuss neutron yields from these sources. We compile a list of ( α , n ) yields for many materials common in low-background detectors, calculated using NeuCBOT (Neutron Calculator Based On TALYS ), a new tool introduced in this paper, available at https://github.com/shawest/neucbot . These calculations are compared to computations made using data compilations and SOURCES-4C .

M. Shamsuzzoha Basunia

Papers

Nuclear Data Sheets for A = 210

Nuclear Data Sheets for A = 28

Nuclear Data Sheets for A = 22

Nuclear Data Sheets for A = 27

Nuclear Data Sheets for A = 30