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Nuclear Science and Techniques 2017年第6期28卷 154-160页

作者： Bin-Qing zhao ming-hua zhao ming Liu Chong-Xian Yin Hang Shu Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

A front-end electronics of dose monitor has been developed for measuring irradiation dose to the patient in Shanghai Advanced Proton Therapy *** parallel plate ionization chamber is used for the dose *** the traditional method of recycling capacitor integration and voltage-to-frequency conversion,this dose monitor electronics uses the trans-impedance amplifier and analog-to-digital conversion *** performs satisfactorily,with the integral nonlinearity of less than ±0.04 nA in the range of-400 to 50 nA and the resolution of about±0.6 nA.

关键词： Front-end electronics Dose monitor Proton therapy

Transverse phase space reconstruction study in Shanghai soft X-ray FEL facility

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Nuclear Science and Techniques 2018年第1期29卷 9-15页

作者： Qing-Lin Yu Duan Gu Meng Zhang ming-hua zhao Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

Phase space is one of the most important parameters used to describe beam properties. Computer tomography, as a method for reconstructing phase space and measuring beam emittance, has been used in many accelerators over the past few decades. In this paper, we demonstrate a transverse phase space reconstruction study in the Shanghai soft X-ray free electron laser facility. First,we discuss the basic principles of phase space reconstruction and the advantage of reconstructing beam distribution in normalized phase space. Then, the phase space reconstruction results by different computer tomography methods based on the maximum entropy(MENT) algorithm and the filtered back projection algorithm in normalized phase space are presented. The simulation results indicate that,with proper configuration of the phase advance between adjacent screens, the MENT algorithm is feasible and has good efficiency. The beam emittance and Twiss parameters are also calculated using the reconstructed phase space.

关键词： Emittance Phase space reconstruction MENT algorithm SXFEL

Multi-port cavity model and low-level RF systems design for VHF gun

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Nuclear Science and Techniques 2020年第1期31卷 80-87页

作者： Kui Liu Lin Li Cheng Wang Qiang Gu ming-hua zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

Very high frequency(VHF) photocathode guns have excellent performance and are being increasingly selected as electron sources for high-repetition-rate X-ray free-electron lasers. As a highly loaded quality factor cavity, the VHF gun requires high stability in the amplitude and phase of the cavity field. However, the gun is microwave powered by two solid-state power sources through two separate power couplers. The input difference between the two power couplers will influence the stability of the cavity field. To systematically study this influence and obtain measurement formulae, a multi-port VHF gun LCR circuit model is built and analyzed. During the warm-up condition, the cavity structure will be deformed due to the large-scale change in the cavity temperature. Then, the deformation will result in cavity resonant frequency changes. To prevent the mechanic tuner from suffering damages due to the frequent and long-distance movement for correcting the cavity resonant frequency, a self-excited loop(SEL) control system is considered for changing the loop phase and make the loop frequency follow the resonant frequency. In this study, a steady-state model of the VHF gun cavity is built for obtaining the optimal input coupler coefficient and the stability requirement of the forward voltage. Then, the generator-driven resonator and SEL control system, which combine with the VHF multiport modeling, are modeled and simulated. The simulated results show that the SEL system can perfectly operate in the process of condition and warm-up.

关键词： VHF photocathode gun Multi-port modeling Self-excited loop LLRF control

Beam performance of the SHINE dechirper

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Nuclear Science and Techniques 2021年第3期32卷 72-81页

作者： You-Wei Gong Meng Zhang Wei-Jie Fan Duan Gu ming-hua zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

A corrugated structure is built and tested on many FEL facilities,providing a'dechirper'mechanism for eliminating energy spread upstream of the undulator section of X-ray *** wakefield effects are here studied for the beam dechirper at the Shanghai high repetition rate XFEL and extreme light facility(SHINE),and compared with analytical *** properly optimized,the energy spread is well *** transverse wakefield effects are also studied,including the dipole and quadrupole *** using two orthogonal dechirpers,we confirm the feasibility of restraining the emittance growth caused by the quadrupole wakefield.A more efficient method is thus proposed involving another pair of orthogonal dechirpers.

关键词： Corrugated structure Energy spread Wakefield Shanghai high repetition rate XFEL and extreme light facility

An S-band solid-state radio frequency power amplifier used at Shanghai soft X-ray FEL facility

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Nuclear Science and Techniques 2016年第6期27卷 86-92页

作者： Hong-Li Ding ming-hua zhao Cheng-Cheng Xiao Shao-Peng Zhong Jun-Qiang Zhang Shanghai Institute of Applied Physics Chinese Academy of SciencesZhangjiangShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

In this paper,we present the general design methods and parameter measurements of a 1-k W solidstate radio frequency(RF) power amplifier at 2856 MHz,for the soft X-ray free electron laser ***-stage amplification with a 4-way combination is *** RF switch module is integrated with the solid-state RF power amplifier to convert the continuous wave(CW) signal into pulse signal,with adjustable pulse *** power gain is measured at 57.7 d B at 60 d Bm *** RF phase noise,which is measured by the low-level RF system,is\0.015 degree(RMS),while the pulse frontier jitter is\5 ns.

关键词：射频功率放大器激光装置自由电子软X射线固态 S波段上海参数测量

边坡中单桩横向受力的试验与理论研究（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2019年第11期20卷 838-851页

作者： ming-hui YANG Bo DENG ming-hua zhao College of Civil Engineering Hunan University

目的:研究边坡段基桩的水平承载特性,以期指导工程实践。创新点:提出一种新的p-y曲线,以考虑边坡坡角和桩在边坡中位置的影响。方法:1.针对平地桩基和坡地桩基两种工况开展两组室内模型对比试验;2.采用ABAQUS建立数值模型,并研究桩径、... 详细信息

目的:研究边坡段基桩的水平承载特性,以期指导工程实践。创新点:提出一种新的p-y曲线,以考虑边坡坡角和桩在边坡中位置的影响。方法:1.针对平地桩基和坡地桩基两种工况开展两组室内模型对比试验;2.采用ABAQUS建立数值模型,并研究桩径、桩长和土体的弹性模量对桩基水平受荷性能的影响;3.对室内模型试验结果和数值模拟结果进行对比分析,并得出坡地桩基的p-y曲线。结论:1.边坡中侧向受力桩的侧向挠度和弯矩沿桩长的分布与水平埋置桩的分布相似;然而,边坡倾角对单桩的侧向荷载特性有着重要的影响;在相同的荷载条件下,较高的倾斜角度会引起较大的桩身变形和弯矩。2.对于埋置长度不变的桩,桩的极限侧向承载力与坡趾距桩截面中心的距离近似呈双线性关系。3.对于埋置长度不同的桩,其极限承载力随坡脚至桩截面中心距离的增加呈线性增加。

关键词：桩基边坡模型试验有限元水平荷载 p-y曲线

SYNTHESIS OF FUNCTIONALIZED CALIX[4]ARENE BEARING [M]DAZOLE MOIETY TO SERVE AS CATALYTIC FUNCTION

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Chinese Chemical Letters 1991年第11期2卷 841-842页

作者： Li hua YUAN zhao Hui ZHEN Shu hua CHEN hua ming zhao Department of Chemistry Sichuan UniversityChengdu 610064

Synthesis of catix[4]arene with one imidazolyl group on the upper rim is presented.

关键词： AS M]DAZOLE MOIETY TO SERVE AS CATALYTIC FUNCTION SYNTHESIS OF FUNCTIONALIZED CALIXARENE BEARING CHC

A STUDY OF THE SURFACE EMERGING PALAEOCHANNELS ON THE SOUTH COAST PLAIN OF LAIZHOU BAY

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Chinese Geographical Science 2000年第3期10卷 54-62页

作者： Mei Han Dao-gao Li ming-hua zhao Ai-xia Jiang Department of Geography Shandong Normal University Jinan P. R. China

By employing many methods including distinguishing the land maps, interpreting the aerophotoes and Satellite photographes, consulting historical documents, investigating ancient cultural relics, making investigations in the field, analysing the names and features of the place, and analysing the characteristics of the deposit, etc., a systematic study of the surface emerging palaeochannels on the South Coast Plain of Laizhou Bay has been made. Twenty five surface emerging palaeochannels were discovered and verified. According to the formation age, these palaeochannels were divided into two stages: six palaeochannels were formed in the Early and Middle Holocene, and nineteen palaeochannels were formed in the Late Holocene(the historical period). According to the landform features, the palaeochannels are divided into four categories: upland palaeochannel belts, strip shaped upland palaeochannels, trough shaped depression palaeochannels and ancient riverbeds. Among the four categories, the strip shaped upland palaeochannels are the main types. The swinging and movement of the channels helped the alluvial plains expand and cause the coastal ancient lakes to vanish in succession.

关键词： the South Coast Plain of Laizhou Bay surface emerging palaeochannels Holocene

RF design and study of a 325 MHz 7 Me V APF IH-DTL for an injector of a proton medical accelerator

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Nuclear Science and Techniques 2019年第9期30卷 34-46页

作者： Xuan Li Yue-Hu Pu Fan Yang Xiu-Cui Xie Qiang Gu Jian Qiao ming-hua zhao Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201210 China Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China Shanghai APACTRON Particle Equipment Co. Ltd Shanghai 201800 China

A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (radio frequency) power, the DTL cavity could establish the corresponding electromagnetic field to accelerate the ‘‘proton bunches’’ from an input energy of 3 MeV to an output energy of 7 MeV successfully, without any additional radial focusing elements. The gap-voltage distribution which was obtained from the CST■ Microwave Studio software simulations of the axial electric field was compared with that from the beam dynamics, and the errors met the requirements within ± 5%. In this paper, the RF design procedure and key results of the APF IH-DTL, which include the main RF characteristics of the cavity, frequency sensitivities of the tuners, and coupling factor of the RF power input coupler are presented.

关键词： Proton therapy Proton medical accelerator Injector Drift-tube linac (DTL) Interdigital H-mode (IH) Alternating-phase-focusing (APF)

Preliminary Systematic Study of the Temperature Effect on the K—Cs—Sb Photocathode Performance Based on the K and Cs Co-Evaporation

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Chinese Physics Letters 2020年第1期37卷 6-9页

作者： Xu-Dong Li Zeng-Gong Jiang Qiang Gu ming-hua zhao Li Guo Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210 Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800

It is very important to increase the quantum efficiency(QE)and prolong the lifetime of the photocathode in a variety of *** have succeeded in preparing a high QE cesium potassium antimonide(K-Cs-Sb)photocathode by K and Cs co-evaporation in the photocathode preparation *** order to better understand the effect of the substrate(photocathode)temperature on the photocathode performance,the photocathode preparation,photocathode performance degradation,photocathode performance recovery and photocathode removal are studied in detail.

关键词： preparing preparation lifetime