Engineering a spin-orbital magnetic insulator by tailoring superlattices

Matsuno, Jobu*; Ihara, Kota*; Yamamura, Shugen*; Wadachi, Hiroki*; Ishii, Kenji; Shankar, V.*; Kee, H.-Y.*; Takagi, Hidenori*

Physical Review Letters, 114(24), p.247209_1 - 247209_5, 2015/06

https://doi.org/10.1103/PhysRevLett.114.247209

Identified charged hadron production in collisions at = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

https://doi.org/10.1103/PhysRevC.83.064903

Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

diffusion in cubic -electron compounds observed by high transverse field SR

Ito, Takashi; Higemoto, Wataru; Oishi, Kazuki*; Nishida, Nobuhiko*; Heffner, R. H.; Aoki, Yuji*; Suzuki, Hiroyuki*; Onimaru, Takahiro*; Tanida, Hiroshi*; Takagi, Shigeru*

Journal of Physics; Conference Series, 225, p.012021_1 - 012021_6, 2010/06

https://doi.org/10.1088/1742-6596/225/1/012021

The diffusion of positive muon in condensed matter has been investigated for many years by using spin rotation/relaxation (SR) technique. The SR studies have provided deep insight into quantum diffusion at low temperatures as well as hopping process at high temperatures, which are closely related to hydrogen dynamics in the dilute limit. We here report transverse field (TF) SR studies of the diffusion in cubic -electron compounds PrPb and SmAgIn. The site splits into two magnetically labeled sites when high TF is applied to single-crystalline specimens along the [001] direction. The SR lines show drastic variation according to the motion between the magnetically labeled sites. From detailed analysis of the SR lines, we deduced hopping parameters for both compounds.

Frustrated minority spins in GeNiO

Matsuda, Masaaki; Chung, J.-H.*; Park, S.*; Sato, Taku*; Matsuno, Kenichiro*; Katori, Hiroko*; Takagi, Hidenori*; Kakurai, Kazuhisa; Kamazawa, Kazuya*; Tsunoda, Yorihiko*; et al.

Europhysics Letters, 82(3), p.37006_1 - 37006_5, 2008/05

https://doi.org/10.1209/0295-5075/82/37006

Recently, two consecutive phase transitions were observed, upon cooling, in an antiferromagnetic spinel GeNiO at K and K, respectively. Using unpolarized and polarized elastic neutron scattering we show that the two transitions are due to the existence of frustrated minority spins in this compound. Upon cooling, at the spins on the 111 kagom planes order ferromagnetically in the plane and antiferromagnetically between the planes (phase I), leaving the spins on the 111 triangular planes that separate the kagom planes frustrated and disordered. At the lower , the triangular spins also order in the 111 plane (phase II). We also present a scenario involving exchange interactions that qualitatively explains the origin of the two purely magnetic phase transitions.

Investigations of different kilovoltage X-ray energy for three-dimensional converging stereotactic radiotherapy system; Monte Carlo simulations with CT data

Deloar, H. M.*; Kunieda, Etsuo*; Kawase, Takatsugu*; Tsunoo, Takanori*; Saito, Hidetoshi*; Ozaki, Masahiro*; Saito, Kimiaki; Takagi, Shunji*; Sato, Osamu*; Fujisaki, Tatsuya*; et al.

Medical Physics, 33(12), p.4635 - 4642, 2006/12

https://doi.org/10.1118/1.2361080

We are investigating three-dimensional converging stereotactic radiotherapy for small lung tumors with better dose homogeneity at the target. A computed tomography radiotherapy was simulated with BEAMnrc X-ray energy of 147.5, 200, 300, and 500 kilovoltage system was validated by comparing calculated and measured percentage of depth dose in a water phantom for the energy of 120 and 147.5 kVp. A thorax phantom and CT data from lung tumors compare dose homogeneities of kVp energies with MV energies of 4, 6, and 10 MV. Three non-coplanar arcs of the target were employed. The Monte Carlo dose data format was converted to the XiO RTP format to compare dose homogeneity, differential, and integral dose volume histograms of kVp and MV energies. In terms of dose homogeneity and DVHs, dose distributions at the target of all kVp energies with the thorax phantom were better than MV energies, with mean dose absorption at the ribs of 100%, 85%, 50%, 30% for 147.5, 200, 300, and 500 kVp, respectively. Considering dose distributions and reduction of the enhanced dose absorption at the ribs, a minimum of 500 kVp is suitable for the lung kVp 3DCSRT system.

Benchmark experiment on LiAlO, LiTiO and LiZrO assemblies with D-T neutrons; Leakage neutron spectrum measurement

Murata, Isao*; Nishio, T.*; Kokooo*; Kondo, T.*; Takagi, H.*; Nakano, D.*; Takahashi, Akito*; Maekawa, Fujio; Ikeda, Yujiro; Takeuchi, Hiroshi

Fusion Engineering and Design, 51-52(Part.B), p.821 - 827, 2000/11

https://doi.org/10.1016/S0920-3796(00)00200-3

no abstracts in English

Detailed magnetic structure of a frustrated spinel CdCrO studied by polarized neutron techniques

Matsuda, Masaaki; Osawa, Akira*; Takeda, Masayasu; Kakurai, Kazuhisa; Chung, J.-H.*; Lee, S.-H.*; Ueda, Hiroaki*; Takagi, Hidenori*

no journal, , 

CdCrO has the spinel structure, in which geometrical frustration exists between the Cr moments located at the corners of the tetrahedron. It shows an incommensurate antiferromagnetic ordering below =7.8K with a characteristic wave vector of (). We first performed a 1D polarized neutron analysis and determined that the Cr moments has a planer anisotropy in the plane, indicating that the magnetic structure is spiral. Finally, the 3D polarized neutron analysis using a CRYOPAD on TAS-1 at JRR-3 determined that the magnetic structure is elliptical spiral in the plane with ellipsoid slightly elongated along the axis. The origin of the structure will be discussed.

Magnetic Structure of a Frustrated Spinel CdCrO

Matsuda, Masaaki; Osawa, Akira*; Takeda, Masayasu; Nakamura, Mitsutaka; Kakurai, Kazuhisa; Lelivre-Berna, E.*; Chung, J.-H.*; Lee, S.-H.*; Ueda, Hiroaki*; Takagi, Hidenori*

no journal, , 

no abstracts in English