Dr Nakajima graduated and received his PhD at Tohoku University (Japan). After spending two years as a postdoctoral fellow at Tohoku University, he moved to Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo as an instrumental scientist of a triple-axis spectrometer PONTA at JRR-3. In 2003, he moved to JAERI (current JAEA) and engaged in construction of a disk-chopper spectrometer AMATERAS. From 2014, he has been section leader of Neutron Science Section of MLF, J-PARC. The scientific interests cover magnetism (quantum spin systems and magnetism in strongly correlated electron systems) and neutron scattering instruments (especially inelastic spectrometers).
Development of a chopper spectrometer with a pulse-shaping chopper at a pulsed source, The 11th JSNS Technology Prize, The Japanese Society for Neutron Science
Phys. Rev. Lett. 123 027206-1-027206-6 Jul 2019 [Refereed]
Magnetic excitations of the effective spin =1/2 dimerized magnet BaCoSiOCl have been probed directly via inelastic neutron scattering experiments. We observed five types of excitation, which are all dispersionless withi...
Details of the background, that is, “unwanted signals accumulated by the data acquisition system of neutron instruments,” observed by the cold-neutron chopper spectrometer AMATERAS installed at the Materials and Life Science Experimental Facility ...
Jinghui Wang, Kejing Ran, Shichao Li, Zhen Ma, Song Bao, Zhengwei Cai, Youtian Zhang, Kenji Nakajima, Seiko Ohira-Kawamura, Petr Cermak, Astrid Schneidewind, Sergey Savrasov, Xiangang Wan, and Jinsheng Wen
Nature Communications 10 28002-1-28002-6 Jun 2019 [Refereed]
Superconductivity mediated by phonons is typically conventional, exhibiting a momentum-independent -wave pairing function, due to the isotropic interactions between electrons and phonons along different crystalline directions. Here, by performi...
M. Teshigawara, Y. Tsuchikawa, G. Ichikawa, S. Takata, K. Mishima, M. Harada, M. Ooi, Y. Kawamura, T. Kai, S. Ohira-Kawamura, K. Nakajima, Y. Ikeda, Y. Kiyanagi
Nuclear Inst. and Methods in Physics Research, A 929 113-120 Jun 2019 [Refereed]
A nano-diamond is an attractive neutron reflection material below cold neutron energy. The total neutron cross section of a nano-diamond produced using the detonation explosive technique was derived from a neutron transmission measurement over the...
Seven time-of-flight quasielastic/inelastic neutron scattering instruments are installed on six beamlines in the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC). Four of these instru...
H. Wo, Q. Wang, Y. Shen, X. Zhang, Y. Hao, Y. Feng, S. Shen, Z. He, B. Pan, W. Wang, K. Nakajima, S. O.-Kawamura, P. Steffens, M. Boehm, K. Schmalzl, J. T. Park, T. R. Forrest, M. Matsuda, Y. Zhao, J. W. Lynn, Z. Yin, and J. Zhao
Phys. Rev. Lett. (122) 217003-1-217003-5 May 2019 [Refereed]
We report neutron scattering measurements of single-crystalline YFeGe in the normal state, which has the same crystal structure as the 122 family of iron pnictide superconductors. YFeGe does not exhibit long-range magnetic ...
Nature Communications 10 2096-(8 pages) May 2019 [Refereed]
Search for topological materials has been actively promoted in the field of condensed matter physics for their potential application in energy-efficient information transmission and processing. Recent studies have revealed that topologically invar...
Bing Li, Yukinobu Kawakita, Seiko Ohira-Kawamura, Takeshi Sugahara, Hui Wang, Jingfan Wang, Yanna Chen, Saori I. Kawaguchi, Koji Ohara, Shogo Kawaguchi, Kuo Li, Dehong Yu, Richard Mole, Takanori Hattori, Tatsuya Kikuchi, Shin-ichiro Yano, Zhao Zhang, Zhe Zhang, Weijun Ren, Shangchao Lin, Osami Sakata, Kenji Nakajima, and Zhidong Zhang
Nature 567 506-510 Mar 2019 [Refereed]
Refrigeration is of vital importance for modern society—for example, for food storage and air conditioning—and 25 to 30 per cent of the world’s electricity is consumed for refrigeration1. Current refrigeration technology mostly involves the conven...
Hiroaki Kadowaki, Mika Wakita, Björn Fåk, Jacques Ollivier, Seiko Ohira-Kawamura, Kenji Nakajima, and Jeffrey W. Lynn
Phys. Rev. B 99 014406-1-014406-12 Jan 2019 [Refereed]
Spin correlations of the frustrated pyrochlore oxide Tb2+xTi2−xO7+y have been investigated by using inelastic neutron scattering on single-crystalline samples (x = −0.007, 0.000, and 0.003), which have the putative quantum-spin-liquid (QSL) or ele...
We investigated magnetic excitations in lightly oxygen doped La2NiO4+d (d = 0.02 and 0.11) by inelastic neutron scattering over a wide energy range. It is known that two types of two-dimensional (2D) antiferromagnetic (AF) excitations coexist in t...
Anomaly of structural relaxation in complex liquid metal of bismuth - Dynamic correlation function of coherent quasi-elastic neutron scattering - 551 291-296 Dec 2018 [Refereed]
P. Wu, B. Zhang, K. L. Peng, M. Hagihala, Y. Ishikawa, M. Kofu, S. H. Lee, H. Kumigashira, C. S. Hu, Z. M. Qi, K. Nakajima, G. Y. Wang, Z. Sun, and T. Kamiyama
Phys. Rev. B 98(9) 094305-1-094305-7 Sep 2018 [Refereed]
SnSe has drawn considerable attention on a global scale due to its intrinsic low thermal conductivity and
large figure of merit along the b axis. In Na-doped SnSe, further enhancement of the thermoelectric performance
has been reported. Using angl...
Bymeans of inelastic neutron scattering,we measured magnetic excitations in a sizable single crystal of La1.7Sr0.3Cu0.95Al0.05O4, which is an Al-substituted system of the heavily hole-doped cuprate system La2-xSrxCuO4 (LSCO) with an effective conc...
Hiroaki Kadowaki, Mika Wakita, Bjorn Fak, Jacques Ollivier, Seiko Ohira-Kawamura, Kenji Nakajima, Hiroshi Takatsu, Mototake Tamai
Journal of the Physical Society of Japan 87(6) 064704-1-064704-6 Jun 2018 [Refereed]
The ground states of the frustrated pyrochlore oxide Tb2+xTi2-xO7+y have been studied by inelastic neutron scattering experiments. Three single-crystal samples are investigated; one shows no phase transition (x = -0.007 < xc < ~ -0.0025), being a ...
IOP Conf. Series: Journal of Physics: Conf. Series 1021 012031-1-012031-5 Jun 2018 [Refereed]
We report recent issues that have been encountered by AMATERAS, which is a cold neutron disk-chopper spectrometer installed at the Materials & Life Science Experimenta Facility at J-PARC. After the last ICANS meeting held in 2014, AMATERAS has con...
To examine the detailed structure of low-energy magnetic excitations in a high-transition-temperature superconducting cuprate with heavily hole-doping, we performed inelastic neutron scattering experiments on La1.75Sr0.25CuO4. We observed clear di...
IOP Conf. Series: Journal of Physics: Conf. Series 969 012024 Apr 2018 [Refereed]
Inelastic neutron scattering experiments were performed to investigate the effect of
Fe substitution on the magnetic excitation spectra in a heavily hole-doped cuprate system
La1.7Sr0.3Cu0.95Fe0.05O4, with an effective concentration of holes of xe...
C. H. Lee, A. Nishida, T. Hasegawa, H. Nishiate, H. Kunioka, S. Ohira-Kawamura, M. Nakamura, K. Nakajima, and Y. Mizuguchi
Applied Physics Letters 112 023903 Jan 2018 [Refereed]
Low energy phonons in LaOBiS2-xSex are studied using inelastic neutron scattering. Dispersionless
flat phonon branches that are mainly associated with a large vibration of Bi atoms are observed at a
relatively low energy of E=6–6.7meV. The phonon ...
A series of meetings to discuss future neutron/muon sources and instruments at Materials and Life Science Experimental Facility (MLF) in Japan Proton Accelerator Research Complex (J-PARC) has been held since 2017. Each of the neutron instrument gr...
RADIOISOTOPES 66(2) 101-115 Feb 2017 [Refereed][Invited]
AMATERAS is a cold-neutron disk-chopper spectrometer
installed at Materials and Life science Facility (MLF)
in J-PARC. The spectrometer is designed to realize both
high-resolution and high-intensity with high flexibility in
inelastic and quasielas...
The Materials and Life Science Division in J-PARC Center has been conducting "JAEA Project Researches", which consists of a several research projects utilizing neutron scattering instruments developed by JAEA in the Materials and Life Science Expe...
Introduction to Modern Chopper Spectrometers at Pulsed Neutron Sources
Kenji Nakajima, Ryoichi Kajimoto
Hamon 25(1) 39-46 Feb 2015 [Refereed][Invited]
Development of a chopper spectrometer with a pulse-shaping chopper at a pulsed source
K. Nakajima, S. Ohira-Kawamura, M. Nakamura, R. Kajimoto, M. Arai
ANBUG-AINSE Neutron Scattering Symposium 2018 20 Nov 2018 ANBUG&AINSE
Materials and Life Science Experimental Facility (MLF) at J-PARC is a user facility providing the world highest class neutron and muon pulsed beam. As a neutron part of MLF, we are serving 20 neutron instruments to user program, which are covering...
AMATERAS is a cold-neutron disk-chopper spectrometer installed at BL14 port of the Materials & Life Science Experimental Facility (MLF) at J-PARC. AMATERAS is one of the first generation disk-chopper spectrometers with pulse-shaping operation as w...
Present and Future of Neutron Scattering Research on Condensed Matter Physics -Future Perspective of US-Japan Cooperative Program on Neutron Scattering- 5 Jun 2018
Materials & Life Science Experimental Facility (MLF) at J-PARC provides the world's highest class of neutron and muon beams as one of the most modern facilities in the world. MLF started its user program in 2008. Currently, 20 neutron instruments ...
Instrument technology and experiences Performance of instruments[Invited]
Kenji Nakajima
The 2nd ESS–J-PARC Collaboration Workshop 19 Jan 2018 The European Spallation Source
Japan Society for the Promotion of Science: Grants-in-Aid for Scientific Research (C)
Project Year: Apr 2012 - Mar 2016 Investigator(s): Kenji Nakajima
Japan Society for the Promotion of Science: Grants-in-Aid for Scientific Research (B)
Project Year: Apr 2008 - Mar 2011 Investigator(s): Kenji Nakajima
Layered transition-metal oxides show interesting phenomena such as high-temperature superconducting. These materials have often have inhomogeneous charge distribution inside. By combing preparing effective sample preparation environment and the hi...
