Beam test of a new radio frequency quadrupole linac for the Japan Proton Accelerator Research Complex

Kondo, Yasuhiro; Morishita, Takatoshi; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Chishiro, Etsuji; Fukuda, Shimpei; Hasegawa, Kazuo; Hirano, Koichiro; Kikuzawa, Nobuhiro; et al.

Physical Review Special Topics; Accelerators and Beams, 17(12), p.120101_1 - 120101_8, 2014/12

https://doi.org/10.1103/PhysRevSTAB.17.120101

We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.

High-power test and thermal characteristics of a new radio-frequency quadrupole cavity for the Japan Proton Accelerator Research Complex linac

Kondo, Yasuhiro; Morishita, Takatoshi; Hasegawa, Kazuo; Chishiro, Etsuji; Hirano, Koichiro; Hori, Toshihiko; Oguri, Hidetomo; Sato, Fumiaki; Shinozaki, Shinichi; Sugimura, Takashi*; et al.

Physical Review Special Topics; Accelerators and Beams, 16(4), p.040102_1 - 040102_8, 2013/04

https://doi.org/10.1103/PhysRevSTAB.16.040102

We performed a high-power test of a new radio-frequency quadrupole (RFQ II) for the J-PARC linac. RFQ II was developed as a spare RFQ because the operating J-PARC RFQ has suffered from a sparking problem. First, the conditioning of RFQ II was carried out; after 50 h of conditioning, RFQ II became very stable with a nominal power and duty of 330 kW and 3%, respectively. Next the thermal properties were measured because the resonant frequency of RFQ II is tuned by changing the temperature of the cooling water. The frequency response was measured and compared to finite-element method simulation results, confirming that the simple two-dimensional model reproduces the experimental data well. The differences in the field distribution with changes in the rf loading and the cooling-water temperature were also measured, and no serious field distortion was observed. Therefore, we conclude that RFQ II can perform well as a high-power rf cavity.

High pressure and high temperature EXAFS and diffraction study of AgI (MS35)

Yoshiasa, Akira*; Arima, Hiroshi; Fukui, Hiroshi*; Okube, Maki*; Katayama, Yoshinori; Otaka, Osamu*

Nihon Kessho Gakkai-Shi, 51(1), p.66 - 69, 2009/02

We have determined a precise P-T phase diagram of AgI by high-temperature high-pressure synchrotron experiments. X-ray diffraction and X-ray absorption measurements were performed using a multi-anvil high pressure apparatus at SPring-8 synchrotron radiation facility. In a disordered rock-salt phase, Ag ions occupy both octahedral and tetrahedral sites. The occupancy of tetrahedral site has a maximum value, 20%, at 2 GPa. A change from rock-salt structure to disordered rock-salt structure is gradual in the X-ray diffraction measurements while it is clearly observed in the X-ray absorption measurements. Analysis of EXAFS Debye-Waller factor is useful because the force constant can be decided directly even at high pressure and high temperature. Pressure influences greatly the effective potential and anharmonicity decreases with increasing pressure.

Comprehensive study on layout dependence of soft errors in CMOS latch circuits and its scaling trend for 65 nm technology node and beyond

Fukui, Hironobu*; Hamaguchi, Masafumi*; Yoshimura, Hisao*; Oyamatsu, Hisato*; Matsuoka, Fumitomo*; Noguchi, Tatsuo*; Hirao, Toshio; Abe, Hiroshi; Onoda, Shinobu; Yamakawa, Takeshi; et al.

Proceedings of 2005 Symposia on VLSI Technology and Circuits, p.222 - 223, 2005/00

no abstracts in English

Pressure-induced sharp coordination change in liquid germanate

Otaka, Osamu*; Arima, Hiroshi*; Fukui, Hiroyuki*; Utsumi, Wataru; Katayama, Yoshinori; Yoshiasa, Akira*

Physical Review Letters, 92(15), p.155506_1 - 155506_4, 2004/04

https://doi.org/10.1103/PhysRevLett.92.155506

Local structures around germanium in liquid germanate have been investigated by means of in situ X-ray absorption measurements up to 9 GPa at 1273 K. Liquid germanate consisting of tetrahedrally coordinated germanium contracts with increasing pressure without significant changes in the local structure up to 2.5 GPa and then shows an abrupt fourfold-to-sixfold coordination change around 3 GPa. The coordination change is completed below 4 GPa where upon a high-density liquid consisting of octahedrally coordinated germanium becomes stable. The GeO octahedron in the high-density liquid is more compressible than that in solids.

Study on Advanced Systematic Function of the JNC Geological Disposal Technical Information Integration System -Research Document-

Ishihara, Yoshinao*; Fukui, Hiroshi*; Sagawa, Hiroshi*; Matsunaga, Kenichi*; Ito, Takaya*

JNC TJ8400 2004-002, 99 Pages, 2004/02

JNC-TJ8400-2004-002.pdf:10.91MB

In this study, while attaining systematization about the technical know-how mutually utilized between geology environmental field, disposal technology (design) field and safety assessment field, the share function of general information in which the formation of an information share and the use promotion between the technical information management databases built for every field were aimed at as an advancement of the function of JNC Geological Disposal Technical Information Integration System considered, and the system function for realizing considered in integration of technical information. (1) Since the concrete information about geology environment which is gradually updated with progress of stratum disposal research, or increases is reflected suitable for research of design and safety assessment, After arranging the form suitable for systematizing technical information, while arranging the technical information in both the fields of design and safety assessment with the form of two classes based on tasks/works, it systematized planning adjustment about delivery of technical information with geology environmental field. (2) In order to aim at integration of 3-fields technical information of geological disposal, based on the examination result of systematization of technical information, the function of mutual use of the information managed in two or more databases was considered. Moreover, while considering system functions, such as management of the use history of technical information, connection of information use, and a notice of common information, the system operation windows in consideration of the ease of operation was examined.

Study on Systematic Integration Technology of design and Safety Assessment for HLW geological Disposal(II)

Ishihara, Yoshinao*; Fukui, Hiroshi*; Sagawa, Hiroshi*; Ito, Takaya*; Matsunaga, Kenichi*; Kohanawa, Osamu*; Kuwayama, Yuki*

JNC TJ8400 2003-038, 41 Pages, 2003/02

JNC-TJ8400-2003-038.pdf:0.48MB

The present study was carried out relating to basic design of the "Geological Disposal Technology Integration System" that will be systematized as knowledge base for design analysis and safety assesment of HLW geological disposal system by integrating organically and hierarchically various technical information in three study field.

Phase relations of AgI under high pressure and high temperature

Otaka, Osamu*; Takebe, Hitoshi*; Yoshiasa, Akira*; Fukui, Hiroshi*; Katayama, Yoshinori

Solid State Communications, 123(5), p.213 - 216, 2002/08

https://doi.org/10.1016/S0038-1098(02)00290-9

Using a multi-anvil high-pressure device and synchrotron radiation, X-ray observations of AgI high pressure and high temperature up to 6.0 GPa and 1000 K have been performed to investigate the phase relations between -AgI, rocksalt-type, disordered rocksalt-type, and liquid phases. The three phases of -AgI, disordered rocksalt-type, and liquid meet in a triple point in the vicinity of 823 K and 1.3 GPa. The melting curve of the disordered rocksalt phase is linear with a positive slope. The transition between rocksalt and the disordered rocksalt phases is a broad and diffuse disordering type within the same structure. The formation of the disordered rocksalt phase has been hence estimated with the variation of a relative intensity ratio of (111) and (200) diffraction from the rocksalt phase. With increasing pressure the rocksalt phase becomes stabel at high temperature. At 6.0 GPa the rocksalt phase directly melts without the transition to the disordered rocksalt phase.

Study on systematic integration technology of design and safety assessment for HLW geological disposal

Ishihara, Yoshinao*; Fukui, Hiroshi*; Sagawa, Hiroshi*; Ito, Takaya*; Matsunaga, Kenichi*; Kohanawa, Osamu*; Kuwayama, Yuki*

JNC TJ8400 2002-042, 247 Pages, 2002/03

JNC-TJ8400-2002-042.pdf:7.48MB

The present study was carried out relating to basic design of the "Geological Disposal Technology Integration System" that will be systematized as knowledge base for analysis and assessment of geological disposal by integrating organically and hierarchically analysis and evaluation method in three study field. The key conclusions are summarized as follows: (1)The examination to construct the virtual geological disposal system which contained the geological environment on the computer was executed aiming at the development of integration and the analysis systems which became working common basic to execute the design and the performance assessment of the geological disposal system. (2) Technological information (I/O information) which became the base was associated with work (evaluation) item of "Disposal technology (design)" and "Performance assessment" in the Second Progress Report by JNC, and the evaluation flow by which a series of work concerning the design and the safety assessment of the geological disposal system was brought together was made. (3) The subject concerning the detailed model development in the R&D activity of the geological disposal system in the future was extracted aiming at the systematization of the performance and safety assessment, and was arranged as information to take these detailed models into the "Geological Disposal Technology Integration System".

Anharmonicity of gold under high-pressure and high-temperature

Okube, Maki*; Yoshiasa, Akira*; Otaka, Osamu*; Fukui, Hiroshi*; Katayama, Yoshinori; Utsumi, Wataru

Solid State Communications, 121(5), p.235 - 239, 2002/02

https://doi.org/10.1016/S0038-1098(01)00494-X

In order to examine the pressure effect on the anharmonicity of Au, EXAFS spectra near Au -edge were measured at the temperature range from 300 to 1000K under pressure up to 14GPa using large volume high-pressure devices and synchrotron radiation. The values of EXAFS Debye-Waller factors, and , become smaller with increase of pressure, which indicates that the potential width become narrower with pressure. The anharmonic effective pair potentials of Au, , at 0.1MPa, 6 and 14GPa have been calculated. The pressure dependence of the coefficient of thermal expansion has also been evaluated.