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Low emittance lattice design with Robinson wiggler in the arc section

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Nuclear Science and Techniques 2017年第1期28卷 57-63页

作者： Shun-Qiang Tian Qing-Lei zhang man-zhou zhang Kun Wang Bo-Cheng Jiang Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China

Beam emittance reduction is an effective method to increase the brightness of a synchrotron light *** wiggler can play a role in the beam emittance reduction by increasing the horizontal damping partition number.A replacement of the quadrupoles in the arc section with short combined function dipoles will construct a single-periodic Robinson wiggler in the SSRF storage *** scheme provides a lower beam emittance,without occupying any straight *** analysis is presented in this paper.

关键词： Emittance reduction Damping partition number Synchrotron light source

Improving Touschek lifetime and synchrotron frequency spread by passive harmonic cavity in the storage ring of SSRF

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Nuclear Science and Techniques 2017年第8期28卷 41-46页

作者： Thanapong Phimsen Bo-Cheng Jiang Hong-Tao Hou Shun-Qiang Tian man-zhou zhang Qing-Lei zhang Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of Sciences Zhangjiang Campus Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

Beam lifetime of a synchrotron is dominated by Touschek *** the beamline Phase II project of Shanghai synchrotron radiation facility,a passive third harmonic cavity is to be installed for bunch lengthening and instability *** this paper,the beam dynamics of the cavity is *** parameters of passive operation are optimized to cancel the slope of RF voltage and lengthen the *** Touschek lifetime increases are estimated for optimum and non-optimum voltage flattening.A tolerance of the operation is studied in case that there is a shift on detuning *** effect caused by reduction in harmonic voltage generated by lengthened bunch distribution is also estimated using iteration *** increase in synchrotron frequency spread due to nonlinearity of the voltage giving to the bunch is found by using tracking *** spread can help in damping coupled bunch instability through Landau damping.

关键词：同步加速器束流寿命谐波上海储存环同步辐射光束线电压降低扩频

Design of a rapid-cycling synchrotron for flash proton therapy

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Nuclear Science and Techniques 2023年第10期34卷 1-11页

作者： Ying Shi man-zhou zhang Lian-Hua Ou-Yang Zhi-Ling Chen Xiu-Fang Li De-Ming Li 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

The purpose of this study was to design a rapid-cycling synchrotron, making it capable of proton beam ultrahigh dose rate irradiation, inspired by laser accelerators. The design had to be cheap and simple. We consider our design from six aspects: the lattice, injection, extraction, space charge effects, eddy current effects and energy switching. Efficiency and particle quantity must be addressed when injected. The space charge effects at the injection could affect particles' number. The eddy current effects in the vacuum chambers would affect the magnetic field itself and generate heat, all of which need to be taken into account. Fast extraction can obtain 10^(10) protons/pulse, equal to instantaneous dose rate up to 10~7 Gy/s in a very short time, while changing various extraction energies rapidly and easily to various deposition depths. In the further research, we expect to combine a delivery system with this accelerator to realize the FLASH irradiation.

关键词： FLASH Rapid-cycling synchrotron Proton therapy

Effect of operational and geometric parameters on the hydrodynamics of a Wurster coater:A CFD-DEM study

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Particuology 2024年第2期85卷 62-76页

作者： Yinqiang Song Tuo zhou Ruiqi Bai man zhang Hairui Yang Department of Energy and Power Engineering Tsinghua UniversityBeijing100084China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua UniversityBeijing100084China State Key Laboratory of Power System and Generation Equipment Tsinghua UniversityBeijing100084China

A coupled CFD-DEM method was used to study the hydrodynamics of a Wurster ***,the CFD part of the model was validated by the accurate prediction of the pressure drops over a pseudo-2D fluidized bed under various gas *** effect of gas velocity,gap height,tube length and batch volume of the particles on the cycle time and the residence time of the particles was thoroughly *** central jet gas velocity ui was found to speed up the particle cycle but undermine the coating *** gas velocity at the horizontal transport zone u2 was able to promote the horizontal transport of the particles but should not be too high,otherwise,it would obstruct the normal falling back of the particles in the downward *** gap heights would decrease the coating efficiency but tube length had little impact on *** increment of batch volume would commonly abase the cycle time and the working efficiency under a given *** de-fluidization problem arose when the batch volume increased to 550 ***,this problem could be swept out by the optimization of u1 and *** a mixture of different sizes,the coarse particles enjoyed higher coating efficiency and could travel closer to the *** may shield the fine particles from getting enough coating liquids,and thus coarse particles and fine particles were not recommended to get coated in the same batch.

关键词： Numerical simulation CFD-DEM Wurster coater Hydrodynamics Cycle time Residence time

Eddy current effects in a high field dipole

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Nuclear Science and Techniques 2017年第12期28卷 198-203页

作者： man-zhou zhang zhang Miao zhang Xiu-Cui Xie Song-Qing Tan Ji-Dong zhang Lian-Hua Ouyang Rui Li De-Ming Li Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China

Eddy currents produced by a time-varying magnetic field will introduce time delay and thus affect field quality. This effect leads to drifting of the beam position over time, especially for a compact *** and measurements of different dipoles have been performed, to investigate the time delay and field quality. The simulations are conducted using OPERA software. The measurements are conducted using a long coil and Hall sensor. All results show that the magnetic field deviation is up to 0.4% for the dipole with stainless steel endplates. The simulations show that the main sources of eddy current are the field saturation effect and the field component Bz, introduced by the bedstead-type coil. Field correction using a power supply is adopted to reduce the deviation to less than 0.02%.

关键词： Eddy current Time delay Magnetic field measurement Dipole Field control

Surface wave inversion with unknown number of soil layers based on a hybrid learning procedure of deep learning and genetic algorithm

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 345-358页

作者： Zan zhou Thomas man-Hoi Lok Wan-Huan zhou Department of Civil and Environmental Engineering Faculty of Science and TechnologyUniversity of MacaoMacaoChina

Surface wave inversion is a key step in the application of surface waves to soil velocity ***,a common practice for the process of inversion is that the number of soil layers is assumed to be known before using heuristic search algorithms to compute the shear wave velocity profile or the number of soil layers is considered as an optimization ***,an improper selection of the number of layers may lead to an incorrect shear wave velocity *** this study,a deep learning and genetic algorithm hybrid learning procedure is proposed to perform the surface wave inversion without the need to assume the number of soil ***,a deep neural network is adapted to learn from a large number of synthetic dispersion curves for inferring the layer ***,the shear-wave velocity profile is determined by a genetic algorithm with the known layer *** applying this procedure to both simulated and real-world cases,the results indicate that the proposed method is reliable and efficient for surface wave inversion.

关键词： surface wave inversion analysis shear-wave velocity profile deep neural network genetic algorithm

Reformatted method for two-dimensional detector arrays measurement data in proton pencil beam scanning

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Nuclear Science and Techniques 2021年第6期32卷 83-93页

作者： Meng-Ya Guo Xiu-Fang Li Jie Wang Qi Liu Xiu-Zhen Deng man-zhou zhang Li-Ren Shen Yue-Hu Pu Zhi-Ling Chen Shanghai Institute of Applied Physics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Shanghai APACTRON Particle Equipment Co.Ltd Shanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

The spatial resolution of a commercial two-dimensional(2D)ionization chamber(IC)array is limited by the size of the individual detector and the center-to-center distance between *** dose distributions with areas of steep dose gradients,inter-detector dose values are derived by the interpolation of nearby detector readings in the conventional mathematical interpolation of 2D IC array *** may introduce significant errors,particularly in proton spot scanning *** this study,by combining logfile-based reconstructed dose values and detector measurements with the Laplacian pyramid image blending method,a novel method is proposed to obtain a reformatted dose distribution that provides an improved estimation of the delivered dose distribution with high spatial ***,the similarity between the measured original data and the downsampled logfilebased reconstructed dose is regarded as the confidence of the reformatted dose ***,we quantify the performance benefits of this new approach by directly comparing the reformatted dose distributions with 2D IC array detector mathematically interpolated measurements and original low-resolution *** result shows that this new method is better than the mathematical interpolation and achieves gamma pass rates similar to those of the original low-resolution *** reformatted dose distributions generally yield a confidence exceeding 95%.

关键词： 2D ion chamber array detectors Laplacian pyramid image blending High-resolution reformatted methods Pencil beam scanning Proton therapy

Optimizing mechanical properties of HIPS fabricated with low-cost desktop 3D printers:investigating the impact of process parameters

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Advances in manufacturing 2024年第2期12卷 379-395页

作者： Jin-Ting Xu Guang-Wei zhang man-man Chen School of Automotive Engineering Dalian University of TechnologyDalian116024People’s Republic of China

Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread ***,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D *** this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were *** experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed *** prediction models of the process parameters were regressed to produce the optimal combination of process *** experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile *** an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer *** addition,they all increased with an increase of infill *** was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were *** results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.

关键词： Desktop three-dimensional(3D)printers Fused deposition modeling(FDM) High-impact polystyrene(HIPS) Process parameters

Longitudinal injection scheme for an ultra-low-emittance storage ring light source with a sine wave kicker

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Radiation Detection Technology and Methods 2019年第4期3卷 29-37页

作者： Kun Wang Chang-Liang Li Zheng-He Bai man-zhou zhang Qing-Lei zhang Bo-Cheng Jiang Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China National Synchrotron Radiation Laboratory USTCHefei 230029China

Methods The method of longitudinal injection to an ultra-low emittance storage ring by a sine wave kicker is investigated in this *** dynamics of the injected and stored beams are both *** a third-harmonic kicker,the ... 详细信息

关键词： Longitudinal injection Storage ring Sine wave kicker