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monte carlo simulation of the property of a scintillation bar in the multi-neutron correlation spectrometer

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Chinese Physics C 2009年第10期33卷 860-865页

作者：宋玉收叶沿林葛愉成吕林辉曲乐实江栋兴华辉郑涛李智焕李湘庆楼建玲卢飞范凤英曹中鑫李奇特肖军 School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University

To perform a kinematically complete measurement of the dissociation reaction for neutron-rich nuclei, a multi-neutron correlation spectrometer is proposed at Peking University. A monte carlo simulation code based on GEANT4 is developed for a single scintillation bar which processes not only the energy deposition but also the light propagation in the scintillator and the light collection and conversion to signal at the end of the bar in a realistic way. The simulating method is described in detail in this paper, and the timing and position resolutions and detector efficiency are studied based on the simulation and compared with the experimental results. A new method of crosstalk rejection has been demonstrated to be important for the design of the whole spectrometer.

关键词： neutron wall monte carlo simulation neutron halo

monte carlo simulation of stage separation dynamics of a multistage launch vehicle

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Applied Mathematics and Mechanics(English Edition) 2008年第11期29卷 1411-1426页

作者： J.Roshanian M.Talebi Department of Aerospace Engineering K.N.Toosi University of TechnologyP.O.Box 16765-3381TehranIran

This paper provides the formulation used for studing the cold and hot separating stages of a multistage launch vehicle. monte carlo simulation is employed to account for the off nominal design parameters of the bodies undergoing separation to evaluate the risk of failure for the separation event. All disturbances, effect of dynamic unbalance, residual thrust, separation disturbance caused by the separation mechanism and misalignment in cold and hot separation are analyzed to find out nonoccurrence of collision between the separation bodies. The results indicate that the current design satisfies the separation requirements.

关键词： ullage-rocket retro-rocket launch vehicle monte carlo simulation hot separation cold separation

monte carlo simulation of glandular dose in a dedicated breast CT system

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Chinese Physics C 2012年第7期36卷 675-680页

作者：唐晓赵维王燕芳舒航孙翠丽魏存峰曹大泉阙介民史戎坚魏龙 Key Laboratory of Nuclear Analytical Techniques Institute of High Energy PhysicsChinese Academy of Sciences Beijing Engineering Research Center of Radiographic Techniques and Equipment Graduate University of Chinese Academy of Sciences

A dedicated breast CT system （DBCT） is a new method for breast cancer detection proposed in recent years. In this paper, the glandular dose in the DBCT is simulated using the monte carlo method. The phantom shape is half ellipsoid, and a series of phantoms with different sizes, shapes and compositions were constructed. In order to optimize the spectra, monoenergy X-ray beams of 5-80 keV were used in simulation. The dose distribution of a breast phantom was studied： a higher energy beam generated more uniform distribution, and the outer parts got more dose than the inner parts. For polyenergtic spectra, four spectra of A1 filters with different thicknesses were simulated, and the polyenergtic glandular dose was calculated as a spectral weighted combination of the monoenergetic dose.

关键词： dedicated breast CT monte carlo simulation glandular dose

monte carlo simulation of Electron Velocity Distribution and Gas Phase Process in Electron-Assisted Chemical Vapor Deposition

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Plasma Science and Technology 2005年第3期7卷 2845-2848页

作者：董丽芳马博琴尚勇王志军 College of Physics Science and Technology Hebei University Baoding 071002 China

The gas phase process of diamond film deposition from CH4/H2 gas mixture by electron-assisted chemical vapor deposition is simulated by the monte-carlo method. The electron velocity distribution under different E/P (the ratio of the electric field to gas pressure) is obtained, and the velocity profile is asymmetric. The variation of the number density of CH3 and H with different CH4 concentrations and gas pressure is investigated, and the optimal experimental parameters are obtained: the gas pressure is in the range of 2.5 kPa - 15 kPa and the CH4 concentration is in the range of 0.5% - 1%. The energy carried by the fragment CH3 as the function of the experiment parameters is investigated to explain the diamond growth at low temperature. These results will be helpful to the selection of optimum experimental conditions for high quality diamond films deposition in EACVD and the modeling of plasma chemical vapor deposition.

关键词： gas phase reactions electron-assisted chemical vapor deposition monte carlo simulation diamond film

monte carlo simulation of Electron Swarm in the Diamond Film Growth via EACVD

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Plasma Science and Technology 2003年第2期5卷 1729-1734页

作者：赵庆勋文钦若杨景发张靖辛红丽 College of Physics Science and Technology Hebei University

monte carlo simulations are adopted to study the electron transport process in the non-uniform electric field. Some important parameters of electrons in diamond films dynamic process at low temperature via EACVD such as angle distribution, energy distribution, average energy of electrons are given. The results indicate that the electron scattering near the substrate is mainly of a large-angle scattering, exhibiting a double-peaking distribution. All of the conclusions provide some theoretical data referential to the vapor dynamic model of diamond film growth at low temperature via EACVD.

关键词： diamond film EACVD monte carlo simulation

monte carlo simulation of B2-L2_1 Ordering Transitions in Au-Cu-Al Alloy Systems

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Journal of Shanghai Jiaotong university(Science) 2011年第2期16卷 186-189页

作者：丁洪徐斌倪昶王京阳金学军 Department of Materials Science and Engineering Shanghai Jiaotong University Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

The B2-L21 ordering transitions in Au-Cu-Al shape-memory alloys are studied by the monte carlo exchange simulations,where a set of the first,the second and the third nearest-neighbor mixing potentials for CuAl in the Au-Cu-Al alloys are calculated from first principals using the Connolly-Williams *** ensure the phase stability of the β-Au-Cu-Al,the investigation includes the range of compositions Au2Cu1-xAl1+x (0.15≤x≤0.15).The B2-L21 transition temperatures are predicted,and are in agreement with the experimental *** atomic ordering around vacancy of the L21 structure is further discussed.

关键词： Au-Cu-Al alloys B2-L21 transitons monte carlo simulation vacancy

monte carlo simulation of in situ Gamma-Spectra Recorded by Na I(Tl) Detector in the Marine Environment

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Journal of Ocean University of China 2015年第3期14卷 471-474页

作者： WANG Yiming ZHANG Yingying WU Ning WU Bingwei LIU Yan CAO Xuan WANG Qian The First Institute of Oceanography SOA Shandong Provincial Key Laboratory of Ocean Environment Monitoring Technology Shandong Academy of Sciences Institute of Oceanographic Instrumentation

To develop a NaI （T1） detector for in situ radioactivity monitoring in the marine environment and enhance the confidence of the probability of the gamma-spectrum analysis, monte carlo simulations using the monte carlo N-Particle （ MNCP ） code were performed to provide the response spectra of some interested radionuclides and the background spectra originating from the natural radionuclides in seawater recorded by a NaI （T1） detector. A newly developed 75 mm × 75 mm NaI （T1） detector was calibrated using four reference radioactive sources 137Cs, 60Co, 40K and 54Mn in the laboratory before the field measurements in seawater. A simulation model was established for the detector immersed in seawater. The simulated spectra were all broadened with Gaussian pulses to reflect the statistical fluctuations and electrical noise in the real measurement. The simulated spectra show that the single-energy photons into the detector are mostly scattering low-energy photons and the high background in the low energy region mainly originates from the Compton effect of the high energy y-rays of natural radionuclides in seawater. The simulated background spectrum was compared with the experimental one recorded in field measurement and they seem to be in good agreement. The simulation method and spectra can be used for the accurate analysis of the filed measurement results of low concentration radioactivity in seawater.

关键词： monte carlo simulation marine radioactivity monitoring NaI (T1) detector response spectra background spectra

monte carlo simulation of Band Texture Formation in Macroscopically Oriented Semirigid Polymer System

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Chemical Research in Chinese Universities 1994年第2期10卷 144-145页

作者： Zhang Hong-dong YAN Dong and YANG Yu-liang (Department of Macromolecular Science, Fudan University, Shanghai, 200433 )

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关键词： Band Texture monte carlo simulation Main-chain liquid crystal poly- mer

monte carlo simulation of a cone-beam CT system for lightweight casts

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Radiation Detection Technology and Methods 2021年第4期5卷 504-512页

作者： Thuy Duong Tran Ngoc Ha Bui Kim Tuan Tran Ngoc Toan Tran Department of Nuclear Engineering and Environmental Physics School of Engineering PhysicsHanoi University of Science and Technology01 Dai Co VietHai Ba TrungHanoiVietnam Vietnam Atomic Energy Institute 59 Ly Thuong KietHoan KiemHanoiVietnam

Cone-beam computed tomography(CBCT),a modern technique with many applications,is becoming increasingly important and essential in many areas of economics and *** equipment has been commercialized in both hardware and ***,having a device system suitable for a specific group of objects will be the *** work used monte carlo simulation to optimize the design of a Cone-beam Computed Tomography(CBCT)for lightweight and small-size *** affecting image quality such as radiation-source,flat-panel detector,and geometrical distance were *** results indicate that an X-ray generator with a focal spot size of 4×4µm^(2),high voltage of 240 kV,and a radiation intensity of 10^(13) photon/s with a flat panel CsI(Tl)detector of 0.3 mm thickness and a pixel size of 0.1–0.2 mm,is suitable for a CBCT to inspect small objects in *** monte carlo model was validated against experiments and to evaluate some characteristics of the existing system.

关键词： Cone-beam computed technology monte carlo simulation Lightweight casts in industry Applied radiation