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Measurement and analysis on distribution of radiation field dose inside thetreatment room of TaiChi Pro multimodal integrated digitalradiotherapy system

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radiation Medicine and Protection 2023年第4期4卷 236-243页

作者： Meinan Yao Zechen Feng Bin Bai Zhiqiang Xuan Yongzhong Ma Institute of radiation Health Protection Beijing Center for Disease Prevention and ControlBeijing 100013China Zhejiang Provincial Center for Disease Control and Prevention Hangzhou 310051China

Objective:To examine the leakage radiation dose from the accelerator module's primary beam self-shielding,aswell as stray radiation levels and distribution in the treatment room across various planes for the innovative X/γmultimodal radiotherapy system,TaiChi Pro,which is the world's first digitally integrated system that combines alinear accelerator,multi-source rotational focused gamma knife,and multi-modal image guidance,in order toformulate treatment room safety strategies and estimate additional radiation doses to patients.Methods:The TaiChi Pro multi-mode integrated radiotherapy system was utilized with a 6 MV X-ray accelerator inthe flatten-filter free(FFF)treatment mode.The system has a primary radiation beam self-shielding,and anisocenter dose rate of 800 cGy/min.For detection points in various planes,an x,y,z coordinate system wasestablished with the isocenter as the origin.To simulate the situation of patient,water-equivalent phantom wasemployed.The ambient dose equivalent and ambient dose equivalent rate at detection points in the radiation fieldwere measured using thermoluminescence dosimeters.Results:The self-shielding area achieved a maximum dose of 114.0 mGy at 1 m distance from the target point after3 min of cumulative irradiation.The leakage radiation ratios at all points remained below 0.5%,fulfilling the selfshielding design requirements.Regarding the couch,the highest radiation was observed in the opposite directionof the beam at the target point.The stray radiation on the treatment bed plane resulted in an ambient doseequivalent that did not exceed 0.5%of the ambient dose equivalent at the central point.Conclusion:The levels and distribution patterns of stray and leakage radiation inside the TaiChi Pro treatmentroom meet the requirements of the relevant national standard.The measured values of indoor radiation levels anddistribution are very useful for room shielding design and personnel protection.

关键词： TaiChi Pro Radiotherapy system Treatment room Leakage radiation Stray radiation radiation field

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Study on CYCIAE-100 radiation field and residual radioactivity

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Chinese Physics C 2009年第S2期33卷 47-49页

作者：毕远杰张天爵贾先禄周正和王峰魏素敏钟俊晴唐传祥 China Institute of Atomic Energy Department of Engineering Physics Tsinghua University

The accelerators should be properly designed to make the radiation field produced by beam loss satisfy the dose limits. The radiation field for high intensity H- cyclotron includes prompt radiation and residual radiation field. The induced radioactivity in accelerator components is the dominant source of occupational radiation exposure if the accelerator is well shielded. The source of radiation is the beam loss when cyclotron is operating. In this paper, the radiation field for CYCIAE-100 is calculated using Monte Carlo method and the radioactive contamination near stripping foil is studied. A method to reduce the dose equivalent rate of maintenance staff is also given.

关键词： cyclotron beam loss radiation field Monte Carlo

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Experimental research on vibrating objects and its radiation field by using nearfield acoustic holography

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Chinese Journal of Acoustics 1994年第4期13卷 323-330页

作者： ZHANG Dejun CHENG Jiaozheng WANG Qun ZHU Nianqiu XIA Xianhua and YAN Jin(Wuhan Institute of Physics. Chinese Academy of Sciences. Wuhan 430071)

In this paper, the nearfield acoustic holography (NAH) imaging system for airborne sound constructed in our own laboratory is presented. Using the system we have measured the mode of vibration and radiation field of a single loudspeaker, two loudspeakers and an unbaffled disk, and gotten interesting results. These results tally with theoretical analysis and computer simulations, and indicate that NAH can be used to research on the relation between the mode of vibration and its radiation field as an effective means.

关键词： radiation field Acoustic holography

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Effects of postselected von Neumann measurement on the properties of single-mode radiation fields

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Chinese Physics B 2020年第9期29卷 199-211页

作者：玉素甫·吐拉克 School of Physics and Electronic Engineering Xinjiang Normal UniversityUrumqi 830054China

Postselected von Neumann measurement characterized by postselection and weak value has been found to possess potential applications in quantum metrology and solved plenty of fundamental problems in quantum theory. As an application of this new measurement technique in quantum optics and quantum information processing, its effects on the features of single-mode radiation fields such as coherent state, squeezed vacuum state and Schrödinger cat sate are investigated by considering full-order effects of unitary evolution. The results show that the conditional probabilities of finding photons, second-order correlation functions, Qm-factors and squeezing effects of those states after the postselected measurement is significantly changed are comparable with the corresponding initial pointer states.

关键词： radiation field postselection weak value statistical properties squeezing parameter

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Molecular Structure and Electronic Spectra of CoS under the radiation fields

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Computers, Materials & Continua 2018年第6期55卷 393-403页

作者： Qijun Wu Limin Han Lingxuan Wang Xun Gong School of Chemical Engineering Guizhou Institute of TechnologyGuiyang550003P.R.China Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics Tsinghua UniversityBeijing100084P.R.China School of Food and Pharmaceutical Engineering Guizhou Institute of TechnologyGuiyang550003P.R.China

We optimized the ground-state stable configuration of CoS molecule in different external radiation fields(0-0.04 atomic units(a.u.))at the basis set level of 6-311G++(d,p)using the B3LYP density functional theory.On this basis,the molecular structure,total energy,energy gap,and the intensities of infrared ray(IR)spectra,Raman spectra,and ultraviolet-visible(UV-Vis)absorption spectra of CoS molecule were computed using the same method.The results showed that the molecular structure changed greatly under the effect of the external radiation fields and had significant dependency on the radiation fields.The total energy of CoS molecule grew slightly at first and then significantly decreased in a monotonous manner.The bond length,dipole moment,and energy gap of the molecule all reduced at first and then increased,with the turning point all at F=0.025 a.***.of the radiation field.The absorption peak of IR spectra and Raman optical activity both had maximums at F=0.03 a.***.with significant red shift.In the external radiation field of F=0.030 a.u.,the absorption wavelength of the UV-Vis absorption spectra showed large blue shift,and a strong absorption peak was observed.

关键词： CoS density functional theory molecular structure radiation field spectra

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Asymptotics for null-timelike boundary problems for general linear wave equations

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Science China Mathematics 2021年第1期64卷 111-128页

作者： Qing Han Lin Zhang Department of Mathematics University of Notre DameNotre DameIN46556USA Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China

We study the linear wave equation□gu=0 in Bondi-Sachs coordinates,for an asymptotically flat Lorentz metric g.We consider the null-timelike boundary problem,where an initial value is given on the null surfaceτ=0 and a boundary value on the timelike surface r=r0.We obtain spacetime Hp-estimates of ru for r>r0 and derive an asymptotic expansion of ru in terms of 1/r as r→∞.

关键词： wave equations radiation field energy estimates asymptotic expansion

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THE SIMULATION ANALYSIS OPTIMIZATION DESIGN OF SPACE-FED PILL-BOX OF PHASED ARRAY ANTENNA

THE SIMULATION ANALYSIS OPTIMIZATION DESIGN OF SPACE-FED PIL...

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1996 CIE International Conference of Radar(ICR’96)

作者： GONG ZHENGJUN LIANG CHANGHONG RADAR INSTITUTE OF THE HUANGHE MACHINE BUILDING FACTORY XIDIAN UNIVERSITY

ISBN: (纸本)0780329147

＜正＞A numerical method for analyzing pill-box feeding system of phased array antenna is presented on the basis of function analysis under ideal condition. The method introduces the environment correction factor of the radiation field by means of using data fitting process and miniaturization measurement technique to execute the system simulation so as to acquire the analysis express of aperture field of space-fed pill-box system in phased array antenna.Then,the optimum design is carried out.The last part of this papers gives a set of optimum design parameters of an actual space feeding system.The experiment results show that the method described is useful for engineering design.

关键词： antenna phased arrays antenna feeds optimisation numerical analysis simulation analysis optimization optimum design parameters pill-box feeding system phased array antenna space-fed pill-box system space feeding system numerical method function analysis environment correction factor radiation field data fitting process aperture field

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The radiation Emission Model of Twisted-Pairs

The Radiation Emission Model of Twisted-Pairs

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1998 International Conference on Microwave and Millimeter Wave Technology

作者： Zhang You Shi Changsheng Electronic Department Tsinghua University

ISBN: (纸本)0780343085

＜正＞This paper establishes the emission model and formulas of the radiation field of twisted-pairs by applying the theory of helix Antenna.Afler considering the existence of the common mode current,we designed an experimental method of measuring the radiation field of the differential mode current on single-segment twisted-pairs terminated with open circuit.The results match calculating results.

关键词： twisted pair cables antenna theory electromagnetic field theory radiation emission model twisted-pairs radiation field helix antenna theory common mode current differential mode current measurement open circuit termination single-segment type

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