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Metoki, Naoto; Yamauchi, Hiroki; Matsuda, Masaaki*; Fernandez Baca, J.*; Yoshida, Masahiro*; Yoshizawa, Hideki*; Hagihara, Masato*; Watanuki, Ryuta*
no journal, ,
We report the magnetic structures and propose the mechanism of the successive transition based on the 
-electron state revealed by CEF excitation. We confirmed the non-collinear `all-in all-out' structure (
) of the in-plane moment. We found that the magnetic moment along the 
-axis 
showed diagonally antiferromagnetic structure (
). The unusual magnetic ordering is phenomenologically understood via Landau theory. We also found that a long-period incommensurate modulation of the (
) antiferromagnetic structure of with the propagation 
= (0.14, 0.14, 0.1) and 
= (0.2, 0, 0.1) in phase III and IV, respectively. We found pseudo-quartet -electron state based on 
and 
. We can propose the intermediated phase as the magnetically ordered phase of 
while 
and 
coupling phase tabilized in low temperatures.
SiKambe, Shinsaku; Hattori, Taisuke; Sakai, Hironori; Tokunaga, Yo; Matsuda, Tatsuma*; Haga, Yoshinori; Walstedt, R. E.*
no journal, ,
High quality YbRh
Si was prepared by concentrating the 
Si isotope which is the NMR nucleus by 52%. Since the natural abundance ratio of Si isotope is about 4%, this concentration can shorten the measured integrated time to about one hundredth. Using this single crystal sample, NMR spin echo attenuation was measured. In the decay curve, in addition to ordinary Gauss type and Lorentz type attenuation, clear vibration term appeared. This is thought to be due to RK interaction and quasi-dipolar interaction. A large temperature change was also observed in this frequency at low temperature. This means that the Fermi surface is temperature dependent. Discuss these behaviors.
Onishi, Hiroaki
no journal, ,
no abstracts in English
Matsubara, Akihiro*; Fujita, Natsuko; Ishii, Kunikazu*
no journal, ,
no abstracts in English
Kai, Takeshi; Yonetani, Yoshiteru*; Yokoya, Akinari*
no journal, ,
Deeply study for radiation DNA damage is very important to understand initial factors for mutation and cancer inductions. Recently, photolysis techniques have revealed that pre-hydrated electrons can induce DNA damage through dissociative electron transfer (DET). The contributions to DNA damage by DET have not been fully investigated in previous theoretical studies. Thus a dynamic Monte Carlo code (DMCC) was developed to consider effect of the DET. From the analysis used by the DMCC, we revealed that pre-hydrated electrons contribute to formation of complex DNA damage. Thus we also have developed a newly calculation method combined with the DMCC and molecular dynamics method. The method makes it possible to predict formation of pre-hydrated electrons. In this presentation, we will report current states of development for the newly method.
Ge, 2Haga, Yoshinori; Matsumoto, Yuji*; Tateiwa, Naoyuki; Yamamoto, Etsuji; Nakamura, Ai*; Honda, Fuminori*; Aoki, Dai*; Yamagami, Hiroshi*
no journal, ,
no abstracts in English
Np isomerKamada, Hiroki*; Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Toyoshima, Atsushi; Nagame, Yuichiro; Mitsukai, Akina; Tomitsuka, Tomohiro*; Andreyev, A. N.; Nishio, Katsuhisa; et al.
no journal, ,
Existence of the previously unknown isomer Np was discovered for the first time. Np was produced by using the JAEA tandem accelerator. Short-lived reaction products were mass-separated by the on-line isotope separator ISOL, and 
and X rays originating from the decay of Np were observed. The half-life of Np was determined to be approximately 9 min, and Np was found to decay via the EC decay as well as the isomeric transition. On the basis of the observed and X rays and the half-life value, we have evaluated level energy, spin-parity, and proton-neutron configuration of Np.
Al
studied by three dimensional ARPESFujimori, Shinichi; Kobata, Masaaki; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika*
no journal, ,
no abstracts in English
Kumada, Takayuki; Akutsu, Kazuhiro*; Oishi, Kazuki*; Morikawa, Toshiaki*; Kawamura, Yukihiko*; Sahara, Masae*; Suzuki, Junichi*; Torikai, Naoya*
no journal, ,
We have developed a technique of spin contrast variation neutron reflectometry (SCV-NR). The reflectivity curve of the polarized neutrons nonsimilarly varies as a function of proton polarization PH of a polymer thin film on silicon substrate. The PH-dependent reflectivity curve determines the roughnesses of the surface and interface of the polymer thin film, whereas single reflection curve of non-polarized neutrons cannot determine uniquely. We consider that the SCV-NR would be a promising technique to determine surface and interface structure of thin films of soft materials.
Yokota, Terufumi
no journal, ,
no abstracts in English
Imai, Masaki; Ogata, Yudai; Chudo, Hiroyuki; Ono, Masao; Harii, Kazuya; Matsuo, Mamoru*; Onuma, Yuichi; Maekawa, Sadamichi; Saito, Eiji
no journal, ,
no abstracts in English
using soft X-ray magnetic circular dichroismTakeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Yamagami, Hiroshi; Yamamoto, Etsuji; Haga, Yoshinori
no journal, ,
no abstracts in English
Fe
O
Shamoto, Shinichi; Ito, Takashi; Onishi, Hiroaki; Matsuura, Masato*; Akatsu, Mitsuhiro*; Nakamura, Mitsutaka; Inamura, Yasuhiro; Kodama, Katsuaki; Kawamura, Seiko; Nemoto, Yuichi*; et al.
no journal, ,
no abstracts in English
Koura, Hiroyuki
no journal, ,
no abstracts in English
O (R: rare earths)Yoshii, Kenji; Nomura, Takuji*; Ikeda, Naoshi*
no journal, ,
The rare-earth iron system RFeO shows ferroelectricity due to charge ordering of iron ions below 330 K. Also, the iron spins shows ferrimagnetism below 250 K and thus becomes multiferroic. Although this system was discovered almost a decade ago, its detailed properties remain unclear. In this study, we have calculated its ground state based on mean-field approximation. Various charge-ordered states have been observed. However, a ferroelectric state was not most stable. This suggests that the ferroelectricity is governed by the other factors such as lattice distortion.
Miura, Akihiko; Miyao, Tomoaki*
no journal, ,
no abstracts in English
Moriya, Katsuhiro; Harada, Hiroyuki; Miura, Akihiko; Futatsukawa, Kenta*
no journal, ,
no abstracts in English
Harada, Hiroyuki; Saha, P. K.; Tamura, Fumihiko; Meigo, Shinichiro
no journal, ,
The 3-GeV rapid cycling synchrotron (RCS) of the J-PARC is a high intensity proton accelerator of 1 MW. The accelerated proton beams in the RCS are extracted by eight pulsed kicker magnets and are delivered to a materials and life science experimental facility and main ring synchrotron. However, the fields of the magnets experience ringing that displaces the position of the extracted beam. This is a major issue from the viewpoint of target integrity and large beam loss. The ringing was directly measured as the displacement of the extracted beams by using a shorter pulsed beam and scanning the entire trigger timing of the kickers. We managed to cancel out the ringing by optimizing trigger timing and achieved the beam extraction with high accuracy. We developed automatic correction system of the timing and now have a higher stability. In this paper, we report our procedure and experimental results for ringing compensation.
Hayashi, Naoki
no journal, ,
In order to realize stable accelerator operation, it is necessary to understand various interlocked events and take countermeasures. In the J-PARC Linac, many interlocked events which include waveform data of current monitors and beam loss monitors, were recorded and classified to the various pattern. Their counter measures are under consideration. In the RCS (Rapid-Cycling Synchrotron), new processing unit is prepared to record beam current and position date of interlocked event and its future perspective will be reported.
Yoshimoto, Masahiro; Okabe, Kota; Harada, Hiroyuki; Kinsho, Michikazu; Kato, Shinichi*
no journal, ,
The charge exchange multi-turn beam injection scheme is adopted in the J-PARC 3GeV Rapid Cycling Synchrotron Accelerator (RCS) due to achieve 1MW beam power operation. In the conventional multi-turn beam injection scheme, which is provided by only the septum and bump magnets, injecting turn numbers are limited by the beam losses at the septum. On the other hand, charge exchange multi-turn beam injection does not cause the beam losses at the septum; there is no restriction in principle on the injecting turn number. However, high residual doses are observed around the stripper foil. During the charge exchange multi-turn beam injection, not only the injecting beam but also circulating beam hit the foil, and then a large number of secondary particles, namely protons and neutrons, are generated. PHITS simulation results indicate that the secondary particles cause the high residual doses around the foil. To verify this examination, secondary particles measurement is key issue. But injection system is too complex to detect the pure signals of the secondary particles from the stripper foil. Thus, a new independent type foil introducing device is installed in the 100
dump beam transport line in order to construct a simple experimental system for secondary particle measurements. We plan the two experiments by using this system; one is a directly secondary particle detecting method, and the other is a radioactivation analysis method with metal sample pieces. Now, we started the study of how the identification of species and energies of the secondary particles with PHITS code. In this presentation, we report the simulation results of the utility of the radioactivation analysis method.