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Oishi, Kazuki*; Igarashi, Daisuke*; Tatara, Ryoichi*; Kawamura, Yukihiko*; Hiroi, Kosuke; Suzuki, Junichi*; Umegaki, Izumi*; Nishimura, Shoichiro*; Koda, Akihiro*; Komaba, Shinichi*; et al.
Journal of Physics; Conference Series, 2462, p.012048_1 - 012048_5, 2023/03
Times Cited Count：0 Percentile：0.2(Physics, Applied)Toyama, Takeshi*; Arakawa, Dai*; Hiramatsu, Shigenori*; Igarashi, Susumu*; Lee, S.*; Matsumoto, Hiroshi*; Odagiri, Junichi*; Tejima, Masaki*; Tobiyama, Makoto*; Hashimoto, Yoshinori*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.981 - 983, 2010/05
Experiences of operating BPM's during beam commissioning at the J-PARC MR are reported. The subjects are: (1) bug report, statistics and especially the effect of a beam duct step, (2) position resolution estimation (
30 micrometers with 1 sec averaging), (3) beam based alignment.
Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Takeda, Osamu; Kanazawa, Kenichiro; Watanabe, Masao; Yamazaki, Yoshio; Kamiya, Junichiro; Takayanagi, Tomohiro; Kuramochi, Masaya; et al.
IEEE Transactions on Applied Superconductivity, 18(2), p.297 - 300, 2008/06
Times Cited Count：4 Percentile：30.89(Engineering, Electrical & Electronic)
edge in NiOTakahashi, Manabu*; Igarashi, Junichi*; Nomura, Takuji
Physical Review B, 75(23), p.235113_1 - 235113_9, 2007/06
Times Cited Count：18 Percentile：60.66(Materials Science, Multidisciplinary)Resonant inelastic X-ray scattering at the edge in NiO is analyzed theoretically. The antiferromagnetic groud state is described by the Hartree-Fock approximation, the core-hole potential is treated within the Born approximation, and the electron correlation effect is considered within the random-phase approximation. Consequently, the observed spectral shape and its dependence on the momentum transfer of scattered photons are explained quantitatively.
Nomura, Takuji; Igarashi, Junichi*; Takahashi, Manabu*
Hoshako, 20(3), p.171 - 179, 2007/05
Recently, electronic excitation spectra have been observed in strongly correlated electron systems such as transition-metal compounds, by utilizing the highly brilliant synchrotron radiation. Among them, momentum dependent excitation spectra are observed in resonant inelastic X-ray scattering (RIXS) experiments at the transition-metal absorption -edge in the hard X-ray regime. The microscopic theory of RIXS constructed recently by the present authors is explained. An essential point is that RIXS spectrum is closely related to the dynamical density correlation function of correlated transition-metal 
electrons. Spectral shapes and momentum dependence observed in several transition-metaloxides are semiquantitatively explained.
Watanabe, Masao; Irie, Yoshiro; Kamiya, Junichiro; Shimada, Taihei; Takayanagi, Tomohiro; Fujimori, Hiroshi*; Igarashi, Susumu*; Kawakubo, Toshimichi*; Nakayama, Hisayoshi*
IEEE Transactions on Applied Superconductivity, 16(2), p.1350 - 1353, 2006/06
Times Cited Count：2 Percentile：18.89(Engineering, Electrical & Electronic)Thick septa are used in the injection and extraction section of the 3 GeV rapid cycling synchrotron of the J-PARC. We have been designing seven thick septum magnets, two for injection, two for beam dump and three for extraction, respectively. These septa require low-loss operations. For the mechanical stability they are operated by direct current. The yoke is made of the soft-iron block. We have been designing them by using the three-dimensional magnet static field calculation code, TOSCA. In this presentation, we discuss about magnetic field flatness in the gap and effects of the leakage fields in the synchrotron.
Fuchimukai, Junichi*; Yamaguchi, Hitoshi*; Meguro, Yoshihiro; Kubota, Toshio*; Igarashi, Shukuro*
Solvent Extraction Research and Development, Japan, 13, p.139 - 146, 2006/00
no abstracts in English
CuO
Nomura, Takuji; Igarashi, Junichi*
Physical Review B, 71(3), p.035110_1 - 035110_5, 2005/01
Times Cited Count：47 Percentile：82.48(Materials Science, Multidisciplinary)The experimental result of resonant inelastic X-ray scattering in LaCuO is theoretically analyzed. The ground state of the system is described within the Hartree-Fock approximation, and the electronic excitation processes are taken account of within the random phase approximation. In the experiment, the spectral shape shows a strong dependence on the transferred momentum of the photon. We have succeeded in reproducing theoretically this dependence quantitatively.
edge of Si; Theoretical analysisNishikawa, Yunori; Usuda, Manabu; Igarashi, Junichi*
Journal of the Physical Society of Japan, 73(11), p.3171 - 3176, 2004/11
Times Cited Count：3 Percentile：26.46(Physics, Multidisciplinary)no abstracts in English
Tomisawa, Tetsuo; Kishiro, Junichi; Hiroki, Fumio; Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Nigorikawa, Kazuyuki*; Toyama, Takeshi*
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.165 - 167, 2004/08
It proceeds with the beam monitor production of the beam diagnosis system with J-PARC. In this paper, the present status of beam position monitors (BPM) for the SDTL is described. The impedance of strip line monitor have been adjusted in the construction of housing and electrodes of the BPM. The 4-stripline BPM has already been examined in the medium energy beam transport (MEBT) line. Preliminary results of beam position measurement for various beam conditions are reported.
Sato, Susumu; Tomisawa, Tetsuo; Hiroki, Fumio; Lee, S.*; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Kondo, Yasuhiro; Hasegawa, Kazuo; Toyama, Takeshi*; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.467 - 469, 2004/08
As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction. For this accelerator, it is required to minimize the beam loss (typically, lower than0.1
1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 
m. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 stripline pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.
Nomura, Takuji; Igarashi, Junichi*
Journal of the Physical Society of Japan, 73(7), p.1677 - 1680, 2004/07
Times Cited Count：26 Percentile：73.65(Physics, Multidisciplinary)We study theoretically the resonant inelastic X-ray scattering in quasi-one-dimensional insulating copper oxides, where the incident photon energy is tuned to the Cu1
-4
absorption energy. Our attention is focused particularly on the strong momentum-transfer dependence of the spectral shape observed in recent experiments. We describe the antiferromagnetic ground state within the Hartree-Fock theory, and consider charge excitations from the ground state within the random phase approximation. By taking account of the electron correlation effects perturbatively, we obtain detailed momentum-transfer dependence of the spectra in a semiquantitative agreement with the experiments.
Tani, Norio; Adachi, Toshikazu*; Igarashi, Susumu*; Watanabe, Yasuhiro; Someya, Hirohiko*; Sato, Hikaru*; Kishiro, Junichi
IEEE Transactions on Applied Superconductivity, 14(2), p.409 - 412, 2004/06
Times Cited Count：17 Percentile：61.57The 3-GeV synchrotron proposed in the JAERI/KEK Joint Project (J-PARC) is a rapid-cycling synchrotron (RCS), which accelerates a high-intensity proton beam from 400-MeV to 3-GeV at a repetition rate of 25-Hz. The 3-GeV synchrotron is used to produce pulsed spallation neutrons and muons. It also works as an injector for a 50-GeV synchrotron. The 3-GeV synchrotron consists of 24 dipole magnets, 60 quadrupole magnets, 18 sextupole magnets and 52 steering magnets. Since the magnets for the 3-GeV synchrotron are required to have a large aperture in order to realize the large beam power of 1 MW, there is a larger fringe field at a pole end than a usual synchrotron magnet. Therefore, it is important to estimate the magnetic field and the effect of multipole component at the fringe field. In this paper, we report the results of the field calculation and mechanical design of RCS magnets.
edge in UGa
; A Band theoretical approachUsuda, Manabu; Igarashi, Junichi*; Kodama, Akio*
Physical Review B, 69(22), p.224402_1 - 224402_5, 2004/06
Times Cited Count：20 Percentile：65.76(Materials Science, Multidisciplinary)Magnetic resonant X-ray scattering (MRXS) at the edge of Ga in an antiferromagnetic phase of UGa is studied on the basis of a band-structure calculation. We find that a relatively large orbital polarization in the unoccupied states of the Ga 
band is induced by the 
orbital polarizations at neighboring U atoms through the Ga and U hybridization, and thereby leading to the large MRXS intensity.
Nishikawa, Yunori; Usuda, Manabu; Igarashi, Junichi*; Shoji, Hironobu*; Iwazumi, Toshiaki*
Journal of the Physical Society of Japan, 73(4), p.970 - 975, 2004/04
Times Cited Count：6 Percentile：41.19(Physics, Multidisciplinary)no abstracts in English
CNagao, Tatsuya*; Igarashi, Junichi
Physica B; Condensed Matter, 345(1-4), p.70 - 73, 2004/03
Times Cited Count：1 Percentile：7.12(Physics, Condensed Matter)To investigate the effect of the lattice distortion on the resonant X-ray scattering (RXS) spectra in DyBC, we study the crystal electric field Hamiltonian to fit the low-lying level scheme. By using the quasi-quartet ground states of the Hamiltonian, we analyze the cooperative Jahn-Teller effect at absolute zero. We find that a certain type of buckling of sheets of B and C atoms is an energetically favored state. This naturally leads to a canted quadrupole ordering phase consistent with the experiment. We show that the obtained lattice distortion gives rise to large intensities on RXS spectra around the Dy L
edge by modulating 5d bands.
calculation of magnetic resonant X-ray scattering spectra in NiOUsuda, Manabu; Takahashi, Manabu*; Igarashi, Junichi
Physical Review B, 69(1), p.014408_1 - 014408_7, 2004/01
Times Cited Count：11 Percentile：49.52(Materials Science, Multidisciplinary)We have investigated the magnetic X-ray scattering spectra around the edge of Ni in antiferromagnetic NiO on the basis of an calculation. By taking account of orbital polarization through the spin-orbit interaction, we reproduce well the spectra obtained experimentally. We have analyzed the contributions of the resonant dipolar, quadrupolar, and non-resonant scattering processes and clarified the mechanism of the resonant magnetic X-ray scattering.
Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Tomisawa, Tetsuo; Hiroki, Fumio; Kishiro, Junichi; Ikegami, Masanori*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira; et al.
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.429 - 431, 2004/00
As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction at Tokai, Japan. For this accelerator, it is required to minimize the beam loss (typically, lower than 0.11 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 micro-meter. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 strip-line pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.
Nagao, Tatsuya*; Igarashi, Junichi
Journal of the Physical Society of Japan, 72(9), p.2381 - 2384, 2003/09
Times Cited Count：10 Percentile：55.03(Physics, Multidisciplinary)We examine the mechanism of the X-ray diffraction process by including the Thomson scattering (TS) term in addition to the resonant X-ray scattering (RXS) term near the Ce L absorption edge in the antiferroquadrupole (AFQ) ordering phase of CeB. Assuming the AFQ order in the 4f states but without any lattice distortion, we obtain the TS intensity comparable to the RXS intensity, owing to the anisotropic charge distribution of 4f states. The present calculation reproduces well the interference pattern between the TS and RXS terms for the (5/2,3/2,3/2) spot observed in the recent experiment. The result suggests that the TS signal as well as the main peak of the RXS signal are a direct reflection of the AFQ order in CeB.
Tomisawa, Tetsuo; Kishiro, Junichi; Igarashi, Zenei*; Lee, S.*; Hiroki, Fumio
Proceedings of 28th Linear Accelerator Meeting in Japan, p.428 - 430, 2003/08
It is an important factor whether to have a beam loss held how, and the part of the beam diagnosis is important with the accurate beam transport, the occurrence of the high quality beam to accelerate a high intensity proton beam to handle with J-PARC linac accelerator safely. It responds to the purpose, and the beam monitor used for this beam diagnosis has it variously. There are an electric current monitor, a phase monitor, a beam position monitor, a profile monitor, a beam size monitor, a screen monitor, a beam loss monitor, and so on. Report it about these beam monitors in the present condition.
