Development of a triplet magnetic lens system to focus a pulsed neutron beam

Oku, Takayuki; Kira, Hiroshi; Shinohara, Takenao; Takata, Shinichi; Arai, Masatoshi; Suzuki, Junichi; Shimizu, Hirohiko*

Journal of Physics; Conference Series, 251(1), p.012078_1 - 012078_4, 2010/12

https://doi.org/10.1088/1742-6596/251/1/012078

A magnetic neutron lens (MNL) based on a sextupole magnet functions as a focusing and defocusing lens for neutrons with positive and negative spin polarity, respectively. By combining the focusing and defocusing functions of the MNLs, we can control neutron beam shape and divergence with high degree of freedom. Adiabatic field connection and spin flipping device make it possible to realize such a multiplet-MNL system. As the MNL has neutron wavelength-dependent focusing property, namely chromatic aberration, it has been proposed that the chromatic aberration can be compensated in the pulsed neutron beam focusing by changing the focusing and defocusing functions of the MNLs of the multiplet-MNL system synchronously with time-of-flight (TOF) of neutrons. This idea was verified based on a numerical simulation. In this study, we designed and constructed a triplet magnetic lens system composed of 3 sextupole permanent magnets and two spin flippers, and performed a pulsed neutron beam focusing experiment with this system. A pulsed neutron beam focusing experiment with the triplet magnetic lens system was performed at the beamline C3-1-2-1 (NOP) of JRR-3 at JAEA. As the results, we nearly satisfied the focal condition with neutron wavelengths from 0.75 to 0.95 nm by changing the lens functions of focusing or defocusing synchronously with the time of flight of the neutrons.

Magnetic structure and local lattice distortion in giant negative thermal expansion material MnCuGeN

Iikubo, Satoshi*; Kodama, Katsuaki; Takenaka, Koshi*; Takagi, Hidenori*; Shamoto, Shinichi

Journal of Physics; Conference Series, 251, p.012014_1 - 012014_4, 2010/12

https://doi.org/10.1088/1742-6596/251/1/012014

Inelastic neutron scattering study of Fe-based superconductor LaFeAsOF

Wakimoto, Shuichi; Ishikado, Motoyuki; Kodama, Katsuaki; Shamoto, Shinichi; Matsuda, Masaaki; Kajimoto, Ryoichi; Iyo, Akira*; Kito, Hijiri*; Eisaki, Hiroshi*; Arai, Masatoshi; et al.

no journal, , 

Supermirror neutron guide installation in high intensity chopper spectrometor, 4SEASONS

Iwahashi, Takaaki; Kambara, Wataru; Ito, Yukihiro; Yoshida, Noboru; Soyama, Kazuhiko; Maruyama, Ryuji; Kajimoto, Ryoichi; Arai, Masatoshi

no journal, , 

4SEASONS is high intensity chopper specrometor for the study of solid state physics such as superconductivity and so on. To archive needed intensity, supermirror guide is selected as a key compornent and the allingment of it is one of key technology. So we install supermirror system in the beamline of 4SEASONS and set up precisery, and measure C-TOF signals. To compare them with calculated one, the allignmet is good enough to archive the needed efficiency of 4SEASONS.

A Feasibility study of neutron powder diffraction under high pressure with the Engineering Materials Diffractometer "TAKUMI" at J-PARC

Abe, Jun; Hattori, Takanori; Komatsu, Kazuki*; Arima, Hiroshi; Arakawa, Masashi*; Okuchi, Takuo*; Kagi, Hiroyuki; Yagi, Takehiko*; Uwatoko, Yoshiya*; Matsubayashi, Kazuyuki*; et al.

no journal, , 

We have examined the feasibility of in situ neutron powder diffraction under high pressure with the Engineering Materials Diffractometer "TAKUMI", which has been constructed at BL19 in the Materials and Life Science Facility (MLF) of J-PARC. We have tested two types of high pressure devices at TAKUMI, a Paris-Edinburgh press and a Palm cubic anvil cell. Neutron poder diffraction profiles of Pb placed in the high pressure devices as a standard material were collected. As results, diffraction peaks of Pb were clearly observed. In this study, it has been confirmed that in situ neutron powder diffraction under high pressure can be made with a combination of the high pressure devices and the TAKUMI at J-PARC.

Internal dynamics of actin detected by neutron scattering

Fujiwara, Satoru; Plazanet, M.*; Matsumoto, Fumiko; Oda, Toshiro*

no journal, , 

F-actin expresses a variety of functions related to cell motility. To understand how such multiple functions are possible, it is important to understand dynamical properties of F-actin at various levels from internal dynamics of the monomers through relative motions between the monomers to large-scale motions of F-actin. As a first step towards this ultimate purpose, we carried out elastic incoherent neutron scattering (EINS) experiments and quasi-elastic neutron scattering (QENS) experiments of F-actin and G-actin. It was shown from the EINS experiments that there are differences in the internal dynamics of F-actin and G-actin. Analysis of the QENS spectra on F-actin and G-actin showed that both in F-actin and G-actin, there are at least two populations of motions with distinct amplitudes and rates, that higher hydration ratios make these motions "faster", and that G-actin tends to have the motions with larger amplitudes and higher rates than those in F-actin.