Current status of the control system for J-PARC accelerator complex

Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.

Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10

J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.

Research on development of high-purity iron-based alloys; Manufacture, analysis of small amount of element and property tests

; ; ; ; Aoto, Kazumi;

JNC TN9400 2000-059, 43 Pages, 2000/05

JNC-TN9400-2000-059.pdf:2.08MB

The purpose of this study is to understand the material properties of manufacturable high-purity iron and high-purity iron-based alloy in present technology and to get an applicable prospect for the structural and functional material of the frontier fast reactor. Then the about 10kg high-purity iron and iron-based alloy were melted using a cold-crucible induction melting furnace under the ultra-high vacuum. Subsequent to that, the compatibility between the melted material and the high-temperature sodium environment which is a special feature of the fast reactor and tensile property at room and elevated temperatures were investigated using the melted materials. Also, the creep test using the high-purity 50%Cr-Fe alloy at 550C in air in order to understand the high temperature creep property. ln addition, the material properties such as thermal expansion coefficient, specific heat and electrical resistance were measured and to evaluate the outlook for the structural material for the fast reactor. The following results were obtained based on the property test and evaluation. (1)lt was possible to melt the about 10kg high-purity ingot and high-purity 50%Cr-Fe alloy ingot using a cold-crucible induction melting furnace under the ultra-high vacuum. (2)The tensile tests of the high-purity 50%Cr-Fe alloy were performed at room and elevated temperatures in order to understand the deformation behavior. From the experimental results, it was clear that the high-purity 50%Cr-Fe alloy possesses high strength and good ductility at elevated temperatures. (3)The physical properties (the thermal expansion coefficient and specific heat etc.) were measured using the high-purity 50%Cr-Fe alloy. lt was clear that the thermal expansion coefficient of high-purity 50%Cr-Fe alloy was smaller than that of SUS304. (4)From the corrosion test in liquid sodium, the ordinary-purity iron showed the weight loss after corrosion test. However the high-purity iron showed ...

Superimposition of a crystal structure over 2-D EM images

Iwasaki, Kenji*; Takagi, Junichi*; Matsumoto, Atsushi

no journal, , 

no abstracts in English

Atomic model building from low resolution electron microscopy images

Matsumoto, Atsushi; Takagi, Junichi*; Iwasaki, Kenji*

no journal, , 

2D hybrid analysis; An Approach to build 3D atomic model from 2D EM image

Matsumoto, Atsushi; Takagi, Junichi*; Iwasaki, Kenji*

no journal, , 

no abstracts in English

Snap residues for integrin activation identified by elastic network normal mode analysis

Matsumoto, Atsushi; Kamata, Tetsuji*; Iwasaki, Kenji*; Takagi, Junichi*; Yura, Kei

no journal, , 

Integrin, a membrane protein with a huge extracellular domain, participates in cell-cell and cell-extracellular matrix interactions for metazoan. A group of integrins are known to perform a large-scale structural change when they are activated, but their mechanism and generality of the conformational change in other integrins remain to be elucidated. We performed normal mode analysis based on the elastic network models of integrin in the bent form to identify key residues dominating the molecular motions toward activation. We simulated the large conformational change of integrin from the bent to the extended forms by iterative normal mode calculations and demonstrated that specific non-bonded interactions involving the key residues work as a snap to lock integrin in the bent form. The importance of the key residues for the conformational change was verified by mutation experiments.

Superimposition of a crystal structure over EM images

Iwasaki, Kenji*; Matsumoto, Atsushi; Takagi, Junichi*

no journal, ,