The Fermi chopper spectrometer 4SEASONS at J-PARC

Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Kawamura, Seiko; Yokoo, Tetsuya*; Nakatani, Takeshi; Maruyama, Ryuji; Soyama, Kazuhiko; et al.

Journal of the Physical Society of Japan, 80(Suppl.B), p.SB025_1 - SB025_6, 2011/01

https://doi.org/10.1143/JPSJS.80SB.SB025

First demonstration of novel method for inelastic neutron scattering measurement utilizing multiple incident energies

Nakamura, Mitsutaka; Kajimoto, Ryoichi; Inamura, Yasuhiro; Mizuno, Fumio; Fujita, Masaki*; Yokoo, Tetsuya*; Arai, Masatoshi

Journal of the Physical Society of Japan, 78(9), p.093002_1 - 093002_4, 2009/09

https://doi.org/10.1143/JPSJ.78.093002

We succeeded in experimentally demonstrating that a series of two-dimensional maps of a dynamical structure factor in momentum-energy space with multiple incident energies can be simultaneously obtained by one measurement. This method reduces the dead time of time-of-flight measurement, and thus it markedly increases the measurement efficiency. Our achievement realized using the Fermi chopper spectrometer 4SEASONS in J-PARC is expected to open up new possibilities of inelastic neutron scattering measurements.

4SEASONS; A High-intensity chopper spectrometer for inelastic neutron scattering at J-PARC/MLF

Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Nakajima, Kenji; Inamura, Yasuhiro; Takahashi, Nobuaki; Maruyama, Ryuji; Soyama, Kazuhiko; Shibata, Kaoru; Suzuya, Kentaro; et al.

no journal, , 

4SEASONS is one of the neutron chopper spectrometers in J-PARC/MLF. It is intended to provide very high counting rate up to 300 meV neutron energy with medium resolution (% at ) to efficiently collect weak inelastic signals from novel spin and lattice dynamics especially in high- superconductors and related materials. To achieve this goal, the spectrometer equips advanced instrumental design such as an elliptic-shaped converging neutron guide coated with high- (-4) supermirror, long-length (2.5 m) He PSDs arranged cylindrically inside the vacuum scattering chamber. Furthermore, the spectrometer is ready for multi-incident-energy measurements by the repetition rate multiplication method with a special Fermi chopper, and polarization analysis with He spin filters. 4SEASONS is now under construction and will be ready to use in December 2008. In this paper, we show the design of 4SEASONS and current status of its construction.

Fermi-chopper neutron spectrometer 4SEASONS

Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Takahashi, Nobuaki; Kawamura, Seiko; Maruyama, Ryuji; Soyama, Kazuhiko; et al.

no journal, , 

no abstracts in English

Spin fluctuation in iron-based superconductors observed by inelastic neutron scattering

Ishikado, Motoyuki; Kodama, Katsuaki; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Mizuno, Fumio; Wakimoto, Shuichi; Iyo, Akira*; Eisaki, Hiroshi*; Arai, Masatoshi; et al.

no journal, , 

no abstracts in English

CuGeO magnetic excitations temperature dependence by neutron inelastic scattering

Mizuno, Fumio; Kajimoto, Ryoichi*; Nakamura, Mitsutaka; Inamura, Yasuhiro; Ikeuchi, Kazuhiko*; Fujita, Masaki*; Nakajima, Kenji; Aizawa, Kazuya; Arai, Masatoshi

no journal, , 

no abstracts in English

The Magnetic phase diagram and field induced ordered phase in NpIn

Metoki, Naoto; Kaneko, Koji; Haga, Yoshinori; Mizuno, Fumio; Sugai, Takashi; Aoki, Dai*; Homma, Yoshiya*; Shiokawa, Yoshinobu

no journal, , 

no abstracts in English

Starting-up of the chopper spectrometer 4SEASONS in J-PARC

Kajimoto, Ryoichi; Nakamura, Mitsutaka; Yokoo, Tetsuya*; Inamura, Yasuhiro; Mizuno, Fumio; Nakajima, Kenji; Takahashi, Nobuaki; Kawamura, Seiko; Maruyama, Ryuji; Soyama, Kazuhiko; et al.

no journal, , 

no abstracts in English

NpIn study by neutron scattering under magnetic field

Mizuno, Fumio; Sugai, Takashi; Kaneko, Koji; Metoki, Naoto; Haga, Yoshinori; Aoki, Dai*; Homma, Yoshiya*; Shiokawa, Yoshinobu*

no journal, , 

NpIn has the AuCu-type cubic structure. The structure is the same as the pressure-induced superconductor CeIn. It was reported that NpIn orders ferromagnetcally below T = 14 K and antiferromagnetically at T = 10 K, and a new field-induced phase (AF+FM) is found by the magnetization measurement. We reported the (0.5 0.5 0) and (0.5 0.5 1) magnetic reflections the last time. But we was not be able to determine the magnetic structure. This time, we study Q = (0.5 0.5 0) by the horizontal magnet. In the case of QH, the magnetic peak is observed, while in the case of QH, the magnetic peak is not observed. Using the relation of Q sin, where is the angle between Q and a magnetic moment, we find that antiferromagnetic modulation component and the external field are parallel. That is, we come to a conclusion that the structure in which the magnetic moments expand and contract along the external field is stable.

Inelastic neutron scattering on iron-based superconductors

Ishikado, Motoyuki; Nagai, Yuki; Kodama, Katsuaki; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Inamura, Yasuhiro; Mizuno, Fumio; Wakimoto, Shuichi; Nakamura, Hiroki; Machida, Masahiko; et al.

no journal, , 

Three years have passed since the discovery of iron-based superconductors, its maximum superconducting transition temperature () is 55 K, resulting in second highest material system next to cuprate high- superconductors. Among various material systems in iron-based superconductors, we have systematically studied on LaFeAsOF (=28 K) of first discovered system and BaFe(As,P) which have recently attracted tremendous attention by the discovery of line nodes in its order parameter. In the session, we present recent results on "spin fluctuation and superconductivity on LaFePO", and "symmetry of order parameter on BaFe(As,P) by inelastic neutron scattering" studied by the chopper spectrometer 4SEASONS (J-PARC).