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Design Consideration of 650-MHz Circular Electron-Positron Collider Klystron and Simulation of Its Beam Tester

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Chinese Physics Letters 2017年第1期34卷 27-31页

作者： Un-Nisa Zaib shigeki fukuda 周祖圣董东王盛昌肖欧正陆志军裴国玺 Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049 University of Chinese Academy of Sciences Beijing 100049 Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049 High Energy Accelerator Research Organization KEKOhoIbaraki 305-0801Japan

We present the first phase R&D for the 800 kW cw, 650MHz klystron for the future circular electron-positron collider (CEPC) project in China. The CEPC requires 192 klystrons and it is desired to be designed in the Institute of High Energy Physics, CAS, and manufactured domestically. Therefore, we present the manufacturing schedule of this project; the three-stage development from the beam test tube to the klystron having a high efficiency structure. Design of the beam test tube that comprises electron gun and collector is presented. First, gun simulation having a modulating anode is performed using DGUN software. The uniform beam trajectories with a beam perveance of 0.64 mu A/V-3/2 are simulated. We employ a Ba-dispenser cathode of radius 35mm with phi 10 hole at the center and obtain a current density on cathode less than 0.45 A/cm(2). The beam trajectories are also simulated over beam test tube of length about 2m with a magnetic field of 213 Gauss. Thermal analysis of the collector is performed using the ANSIS-CFX code and hence the cooling structure is determined. Mechanical design is almost carried out and it is in manufacturing stage.

关键词： ELECTRON-positron interactions COLLIDERS (Nuclear physics) KLYSTRONS COMPUTER simulation COOLING CATHODES CURRENT density (Electromagnetism)

Design and high-power test of 800-kW UHF klystron for CEPC

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Chinese Physics B 2022年第8期31卷 154-159页

作者： Ou-Zheng Xiao shigeki fukuda Zu-Sheng Zhou Un-Nisa Zaib Sheng-Chang Wang Zhi-Jun Lu Guo-Xi Pei Munawar Iqbal Dong Dong Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China High Energy Accelerator Research Organization KEKOhoIbaraki 305-0801Japan

To reduce the energy demand and operation cost for circular electron positron collider(CEPC), the high efficiency klystrons are being developed at Institute of High Energy Physics, Chinese Academy of Sciences. A 800-k W continuous wave(CW) klystron operating at frequency of 650-MHz has been designed. The results of beam–wave interaction simulation with several different codes are presented. The efficiency is optimized to be 65% with a second harmonic cavity in three-dimensional(3D) particle-in-cell code CST. The effect of cavity frequency error and mismatch load on efficiency of klystron have been investigated. The design and cold test of reentrant cavities are described, which meet the requirements of RF section design. So far, the manufacturing and high-power test of the first klystron prototype have been *** the gun operated at DC voltage of 80 k V and current of 15.4 A, the klystron peak power reached 804 k W with output efficiency of about 65.3% at 40% duty cycle. The 1-d B bandwidth is ±0.8 MHZ. Due to the crack of ceramic window, the CW power achieved about 700 kW. The high-power test results are in good agreement with 3D simulation.

关键词： klystron cavity beam–wave interaction circular electron positron collider(CEPC) high-power test

Development of RF windows for 650 MHz multibeam klystron

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Nuclear Science and Techniques 2023年第9期34卷 58-68页

作者： Sheng-Chang Wang Zu-Sheng Zhou Zhi-Jun Lu Zhi-Qing Liu shigeki fukuda Yu Liu Jing-Yi Li Wei-Ming Li National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Kunshan Guo Li Electronic Technology Co. Ltd.Kunshan 215300China High Energy Accelerator Research Organization KEK 1-1 OhoTsukubaIbaraki 305-0801Japan

Radio frequency windows are developed and evaluated for a 650 MHz continuous-wave multibeam ***-pillbox windows with alumina and beryllia disks are designed with an average RF power of CW 400 *** of a cold test and tuning procedures are *** final measured S11 curves under the required bandwidth are less than-32.0 and-26.9 dB for alumina and beryllia windows,*** windows are tested up to CW 143 kW for traveling waves and CW 110 kW for standing waves using a solid-state amplifier as an RF power *** simulations for windows and benchmark studies for the thermal analysis of ceramic disks are introduced.

关键词： RF window High-power test MBK

Design and development of radio frequency output window for circular electron–positron collider klystron

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Chinese Physics B 2018年第11期27卷 620-625页

作者： Zhijun Lu shigeki fukuda Zusheng Zhou Shilun Pei Shengchang Wang Ouzheng Xiao UnNisa Zaib Bowen Bai Guoxi Pei Dong Dong Ningchuang Zhou Shaozhe Wang Yunlong Chi Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China High Energy Accelerator Research Organization KEK Oho Ibaraki 305-0801 Japan GLVAC Industrial Technology Research Institute of High Power Devices Kunshan 215300 China

This paper presents the first phase of design, analysis, and simulation for the klystron coaxial radio frequency（RF）output window. This study is motivated by 800 kW continuous wave（CW）, 650 MHz klystrons for the future plan of circular electron–positron collider（CEPC） project. The RF window which is used in the klystron output section has a function to separate the klystron from the inner vacuum side to the outside, and high RF power propagates through the window with small power dissipation. Therefore, the window is a key component for the high power klystron. However, it is vulnerable to the high thermal stress and multipacting, so this paper presents the window design and analysis for these problems. The microwave design has been performed by using the computer simulation technology（CST） microwave studio and the return loss of the window has been established to be less than-90 d B. The multipacting simulation of the window has been carried out using MultiPac and CST particles studio. Through the multipacting analysis, it is shown that with thin coating of TiN, the multipacting effect has been suppressed effectively on the ceramic surface. The thermal analysis is carried out using ANSYS code and the temperature of alumina ceramic is lower than 310 K with water *** design result successfully meets the requirement of the CEPC 650 MHz klystron. The manufacturing and high power test plan are also described in this paper.

关键词： klystron coaxial radio frequency window thermal stress multipacting

Erratum:Design Consideration of 650-MHz Circular Electron-Positron Collider Klystron and Simulation of Its Beam Tester[***.34(2017)012902]

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Chinese Physics Letters 2018年第6期35卷 111-111页

作者： Un-Nisa Zaib shigeki fukuda Zu-Sheng Zhou Dong Dong Sheng-Chang Wang Ou-Zheng Xiao Zhi-Jun Lu Guo-Xi Pei Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049 University of Chinese Academy of Sciences Beifing 100049 Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049 a High Energy Accelerator Research OrganizationKEKOhoIbaraki 305-0801Japan

We found an error in our previous report [Chin. Phys. Lett. 34 （2017） 012902] concerning about the value of voltage on the modulating anode （MA）. This mistake occurs when we shifted calculating positive scale to actual negative voltage scale in the DGUN simulation. The value of voltage on the MA is VMA = -33.5 kV as displayed in Table 1. Also Figs. 2（a）, 2（b） and 4（a） should be as follows. We note that the error does not affect the conclusion of our report at all, and we apologize for inconvenience of readers brought by our oversight.

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Recent trends in bone metastasis treatments:A historical comparison using the new Katagiri score system

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World Journal of Clinical Cases 2024年第15期12卷 2499-2505页

作者： Kenji Matsuda Kazuhiro Shimazu Hanae Shinozaki Koji fukuda Taichi Yoshida Daiki Taguchi Kyoko Nomura Hiroyuki Shibata Department of Clinical Oncology Akita University Graduate School of MedicineAkita 010-8543Japan Department of Environmental Health Science and Public Health Akita University Graduate School of MedicineAkita 010-8543Japan Department of Comprehensive Cancer Control Akita University Graduate School of MedicineAkita 010-8543Japan

BACKGROUND Bone metastasis has various negative *** of daily living(ADL)and quality of life(QOL)can be significantly decreased,survival may be impacted,and medical expenses may *** is estimated that at least 5%cancer patients might be suffering from bone *** 2016,we published the Comprehensive Guidelines for the Diagnosis and Treatment of Bone *** then,the therapeutic outcomes for patients have gradually *** life expectancy is a major determinant of surgical intervention,the strategy should be modified if the prolongation of survival is to be *** To monitor how bone metastasis treatment has changed before and after launch of our guidelines for bone *** For advanced cancer patients with bone metastasis who visited the Department of Clinical Oncology at Akita University hospital between 2012 and 2023,parameters including the site and number of bone metastases,laboratory data,and survival time,were extracted from electronic medical records and the Katagiri score was *** association with survival was determined for each *** Data from 136 patients were *** 1-year survival rate for the poor prognosis group with a higher Katagiri score was 20.0%in this study,which was 6%and an apparent improvement from 2014 when the scoring system was *** factors significantly affecting survival included five or more bone metastases than less(P=0.0080),and treatment with chemotherapy(P<0.001),bone modifying agents(P=0.0175)and immune checkpoint inhibitors(P=0.0128).In recent years,advances in various treatment methods have extended the survival period for patients with advanced *** is necessary not only to simply extend survival time,but also to maintain ADL and improve *** Various therapeutic interventions including surgical approach for bone metastasis,which is a disorder of locomotor organs,are increasingly *** and scoring system for p

关键词： Bone metastasis New Katagiri scoring system Prognosis Immune check point inhibitors Survival

Shot lining of magnesium alloy with hard powders

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Transactions of Nonferrous Metals Society of China 2010年第B07期20卷 708-712页

作者： Y.HARADA I.fukuda Graduate School of Engineering University of Hyogo Yatsushiro National College of Technology

To improve the surface properties,lining of magnesium alloys with hard powders by shot peening was carried out in order. The hard powders were tried to bond to the workpiece surface due to the collision of many *** order to fix the hard powders to the surface of the workpiece,the powders were set on an uneven *** easily facilitate fixing of powders,lining of the workpiece with the powder sandwiched between two aluminum foil sheets was also *** this experiment,a centrifugal shot peening machine with an electrical heater was *** workpieces were magnesium alloys AZ31B and AZ91D,and the hard powders were commercial cemented carbide,alumina,and *** joinability of hard powders near the lined surface was observed by a optical *** wear resistance was also evaluated by a wear *** hard powders were successfully bonded to the surface of workpieces by the shot lining *** results show that the present method is effective in wear resistance of the magnesium alloys.

关键词： shot peening surface treatment lining joining joinability magnesium alloy hardness wear resistance cemented carbide ceramic

Regulation of Vascular Development by CLE Peptide-receptor Systems

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Journal of Integrative Plant Biology 2010年第1期52卷 8-16页

作者： Yuki Hirakawa Yuki Kondo Hiroo fukuda Department of Biological Sciences Graduate School of ScienceThe University of Tokyo

Cell division and differentiation of stem cells are controlled by non- cell-autonomous signals in higher organisms. The plant vascular meristem is a stem-cell tissue comprising procambial cells that produce xylem cells on one side and phloem cells on the other side. Recent studies have revealed that TDIF （tracheary element differentiation inhibitory factor）/CLE41/CLE44 peptide signal controls the procambial cell fate in a non-cell-autonomous manner. TDIF produced in and secreted from phloem cells is perceived by TDR/PXY, a leucine-rich repeat receptor kinase located in the plasma membrane of procambial cells. This signal suppresses xylem cell differentiation of procambial cells and promotes their proliferation. In addition to TDIF, some other CLE peptides play roles in vascular development. Here, we summarize recent advances in CLE signaling governing vascular development.

关键词： TDIF Regulation of Vascular Development by CLE Peptide-receptor Systems

Prediction of Aerodynamic Noise in a Ring Fan Based on Wake Characteristics

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Journal of Thermal Science 2011年第2期20卷 144-149页

作者： Soichi Sasaki Masaharu fukuda Masao Tsujino Haruhiro Tsubota Faculty of Engineering Nagasaki University 1-14 Bunkyo-machi Nagasaki 852-8521 Japan Graduate School of Science and Technology Nagasaki University 1-14 Bunkyo-machi Nagasaki 852-8521 Japan Research Division Komatsu Ltd.1200 Manda Hiratsuka-shi Kanagawa 254-8567 Japan

A ring fan is a propeller fan that applies an axial-flow impeller with a ring-shaped shroud on the blade tip side. In this study, the entire flow field of the ring fan is simulated using computational fluid dynamics (CFD); the accuracy of the CFD is verified through a comparison with the aerodynamic characteristics of a propeller fan of current model. Moreover, the aerodynamic noise generated by the fan is predicted on the basis of the wake characteristics. The aerodynamic characteristic of the ring fan based on CFD can represent qualitatively the variation in the measured value. The main flow domain of the ring fan is formed at the tip side of the blade because blade tip vortex is not formed at that location. Therefore, the relative velocity of the ring fan is increased by the circumferential velocity. The sound pressure levels of the ring fan within the frequency band of less than 200 Hz are larger than that of the propeller fan. In the analysis of the wake characteristics, it revealed that Karman vortex shedding occurred in the main flow domain in the frequency domain lower than 200 Hz ; the aerodynamic noise of the ring fan in the vortex shedding frequency enlarges due to increase in the relative velocity and the velocity fluctuation.

关键词： Fan Vortex Aerodynamic Noise Wake Internal Flow