最新刊期
      卷 39 ， 期 4 ， 2016
      • Yongmei WEN,Li WANG,Fei GAO,Sen SUN,Yuxi DONG
        Vol. 39, Issue 4, Article number: 040101(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040101
        摘要：Background:The high position accuracy of the key parts such as the quadrupole magnet relative to the beam center is very important for the Free Electron Laser(FEL) equipment, and will directly affect the quality of the beam.Purpose:This study aims to realize the precise beam-based aligment of the quadrupole by mechanical design of a remote-controlled quadrupole mover.Methods:Beam based alignment(BBA) technique was applied to adjusting the center position of quadrupole with a remote-controlledhigh accuracy mover and its control system. Experimental tests and analysis for the quadrupole mover by the different feedback control were carried out for the undulator segments of the soft X-ray FEL(SXFEL) in Shanghai and the Dalian Coherent Light Source(DCLS) project in China.Results:The positioning accuracy and repeatability error of the quadrupole mover is less than 3μm by the grating ruler feedback control, but it is more than 3μm by the rotary encoder feedback control.Conclusion:The mechanical design and experimental tests of the quadrupole mover areaccomplished. The positioning accuracy and repeatability of the quadrupole mover meet the design indices by the grating ruler feedback control.  
        关键词：BBA;Aremote-controlled quadrupole mover;Positioning accuracy;Repeatability   
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        发布时间：2021-05-25
      • Lianfa HUA,Wenyan ZHANG,Xingtao WANG,Zhen LI,Bo LIU
        Vol. 39, Issue 4, Article number: 040102(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040102
        摘要：Background:The longitudinal length of electron bunch is an important parameter in beam diagnostics. Electro-Optical Spectral Decoding(EOSD) is one of the few powerful approaches to accurately measure bunches down to sub-picosecond level.Purpose:This study aims to design and evaluate a complete system to measure the bunch length at Shanghai Deep Ultraviolet Free Electron Laser(SDUV-FEL).Methods:The EOSD with a probe used for coarse synchronization and a tunable grating pair used as laser stretcher was designed, and the processes of Electro-Optical modulation and detection were simulated in detail.Results:The bunch length varying from 1 ps to 10ps can be measured without beam destruction in the whole process. The time resolution(Root Mean Square, RMS) is expected up to 180 fs at best and signal broadening within 3%.Conclusion:The longitudinal bunch length can be measured with high quality utilizing our EOSD setup. The system can meet the demands of SDUV-FEL.  
        关键词：Bunch length;EOSD;Coulomb field;Broadening and distortion;Beam diagnostics   
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        发布时间：2021-05-25
      • Pan WANG,Jun XIAO,Yingying LI,Ziyue LI,Chao WANG
        Vol. 39, Issue 4, Article number: 040201(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040201
        摘要：Background:As a kind of important activating material, accurate measurement of115In neutron inelastic scattering cross section data of neutron flux monitoring is of great significance.Purpose:The purpose is to measure115In neutron inelastic scattering cross section, and compare the results with the existing data.Methods:The cross section at 2.95 MeV, 3.94 MeV and 5.24 MeV was measured using the activation technique at a 2.5 MeV electrostatic accelerator of Sichuan University, and the reaction of D(d, n)3He was used for neutron sources. The deflections which were caused by multiple scattering and self-shielding of the experiment were corrected with MCNPX.Results:115In neutron inelastic scattering cross section data at three energy values were obtained after Monte Carlo correction and the results fit well with the calculated values of Loevestam.Conclusion:The effect of multiple scattering effects and self-shielding effect can be reduced by reducing the thickness of the target tube, bottom lining, water layer and cladding material of the sample.  
        关键词：115In neutron inelastic scattering cross section;Activation method;Monte Carlo correction   
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        发布时间：2021-05-25
      • Jianxi LI,Yongdong SHAN,Jia GU
        Vol. 39, Issue 4, Article number: 040202(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040202
        摘要：Background:Ultra-high molecular weight polyethylene(UHMWPE) is a kind of widely used engineering plastics due to its excellent physical and chemical properties. But it has the poor creep resistance.Purpose:The aim is to improve its creep resistance, environmental stress cracking and shape stability.Methods:The UHMWPE sheets were irradiated inair, water, methanol and ethanol at the dose rate of 2.5kGy·h-1in the range of 0-200kGy. And the UHMWPE samples were tested and characterized by mechanical properties, gel content, differential scanning calorimetry(DSC) and infrared spectra.Results and Conclusion:The mechanical property test results revealed that the elongation at break of UHMWPE samples decreased obviously with the increasing of radiation dose. In water, methanol and ethanol, the elongation at break of UHMWPE samples also decreased with the increasing radiation dose, but the decrease degree was reduced, while the yield strength remained unchanged. DSC test results showed that the initial melting temperature, melting point and crystallinity of the UHMWPE samples decreased with the increasing absorbed dose in the air atmosphere, while increased in the atmosphere of water, methanol and ethanol. Infrared spectrum test results showed that the oxidation on the surface of the UHMWPE samples increased with the absorbed dose irradiated in the atmosphere of air, and in water, methanol and ethanol, the molecular chains of UHMWPE molecules generated double bond under radiation.  
        关键词：UHMWPE;γ-rays;Radiation environment;Mechanical properties;Crystallinity   
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        发布时间：2021-05-25
      • Yayun MIAO,Ming GU,Zhihao CHEN,Jin TONG
        Vol. 39, Issue 4, Article number: 040401(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040401
        摘要：Background:Proton therapy centers have been operated worldwide recently. The central rationale for proton therapy is its superior spatial dose distribution in the patient. Injection system of synchronous storage ring in Shanghai proton therapy equipment requires two bump magnets.Purpose:Two new pulsed power supplies of the same parameters used in the bump magnet have been proposed and developed.Methods:The principle of pulse forming circuit is thatLCseries resonance generates when thyristor is turned on by trigger signals. Energy storage capacitor is charged to the setting voltage which determines the amplitude of the pulse waveform based on constant current by charging power supply. The main circuit employs variable inductance to adjust the pulse width. Fast recovery diode in series of thyristor could compensate for the turn-off delay of the thyristor while the peak of reverse current decreases due to saturable inductor.Results:Test results showed that when the half-sineexcitation current peak was set to 3732 A, its trigger jitter and reproducibility were less than ±25 ns and 0.1%, respectively. Reverse current could be reduced to 3.75% of the peak current.Conclusion:Experimental results indicate that the pulse power supply reaches the design requirements and saturable inductor restrains reverse current effectively.  
        关键词：Proton therapy;Pulsed power supply;LC resonance;Saturable inductor   
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        发布时间：2021-05-25
      • Zhenwei SHI,Ran HAN,Yixue CHEN
        Vol. 39, Issue 4, Article number: 040402(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040402
        摘要：Background:Resistive Plate Counter(RPC), which is of good performance at low cost and is suitable for large area production, has been proposed as the veto detector for Jiangmen Underground Neutrino Observatory(JUNO). However, RPC made of float glass is fragile and susceptible to damp and corrosion in underground experiments.Purpose:This study aims to improve the performance of RPC to enhance its stability and lifetime.Methods:Three RPCs made of three different chemically strengthened glass are tested with cosmic ray. First of all, the properties of these glass were studied to show its high-strength, corrosion-resistant, high bulk resistivity. Then the variation of detection efficiency, single counting rate and dark current curves of RPCs are verified in avalanche mode.Results:The test results show that the chamber's efficiency is between 90% and 95% and the single counting rate is at a relatively low level.Conclusion:RPCs made of chemically strengthened glass works well due to the high bulk resistivity. In order to reach plateau operation, higher voltage is required for RPC to suitable working in a very low rate background experiment.  
        关键词：RPC;Cosmic ray;Veto;Neutrino experiment   
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        发布时间：2021-05-25
      • Wenjing CHENG,Zhao ZHANG,Han YI,Liming LYU,Zhigang XIAO
        Vol. 39, Issue 4, Article number: 040403(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040403
        摘要：Background:Multi Wire Drift Chamber(MWDC) array is the tracking detector at Cooling storage ring External-target Experiment(CEE) under design at Heavy Ion Research Facility at Lanzhou-Cooling Storage Ring(HIRFL-CSR). The physical goal of CEE aims at the studies of the equation of state of nuclear matter at low temperature but high baryon density. The MWDC array needs a large amount of front end electronics followed by a scalable data acquisition system, which are all costly.Purpose:The aim is to design a readout scheme which can lower the cost but keep the performance of the array rarely degraded, and to test the system and demonstrate the feasibility of the design.Methods:Based on the Flash Analog-to-Digital Converter(ADC) acquisition scheme, a fan-in and delay module has been designed in order to record three signals from X, U and V sense wires simultaneously in each Flash-ADC channel.Results:By this means the total number of channels for MWDC is reduced by 60%. The performance of this fan-in and delay module is tested with a MWDC detector using55Fe X-ray source. The amplitude signal and the timing signal are smeared by less than 1% and 500 ps, respectively.Conclusion:Both specifications show that the fan-in and delay module can be used in MWDC with the event rate ranging in 1-10kHz.  
        关键词：MWDC;Flash-ADC;Fan-in and delay;Time resolution;Energy resolution   
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        发布时间：2021-05-25
      • Wending FAN,Guangyao SUN,Binhang ZHANG,Rui CHEN,Lijuan HAO
        Vol. 39, Issue 4, Article number: 040501(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040501
        摘要：Background:Burnup calculation is the key point of reactor design and analysis. It's significant to calculate the burnup situation and isotopic atom density accurately while a reactor is being designed.Purpose:Based on the Monte Carlo particle simulation code SuperMC(Super Monte Carlo Simulation Program for Nuclear and Radiation Process), this paper aimed to conduct preliminary study and verification on Monte Carlo burnup calculations.Methods:For the characteristics of accuracy, this paper adopted Chebyshev rational approximation method(CRAM) as the point-burnup algorithm. Moreover, instead of the union energy grids method, this paper adopted an energy searching method based on bucket sort algorithm, which reduced the memory overhead on the condition that the calculation efficiency is ensured.Results:By calculating the fuel rod burnup problem and the IAEA-ADS(International Atomic Energy Agency-Accelerator Driven Systems) international benchmark, the simulation results were basically consistent with Serpent and other counties' results, respectively. In addition, the bucket sort energy searching method reduced about 95% storage space compared with union energy grids method for IAEA-ADS benchmark.Conclusion:Depending on these results, the correctness of burnup calculations method implemented by this paper has been verified.  
        关键词：Burnup;Monte Carlo;CRAM;Bucket sort   
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        发布时间：2021-05-25
      • Bicheng LI,Danhui HE,Yun GUO
        Vol. 39, Issue 4, Article number: 040502(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040502
        摘要：Background:The predicted superheat degree of the onset of boiling point is always lower than that of experiment. Hence, a new model is necessary for the accuracy prediction in engineering calculation.Purpose:This study aims to investigate the reason of deviation and bring out a new prediction model, which can be used in engineering analysis directly and simply.Methods:Based on the vapor growth model and the viewpoint of force balance, the onset of fluid vaporization(OFV) and onset of nucleate boiling(ONB) points are separated. Thereby a new analysis model is built and combined with phenomenological analysis method.Results:The formulas to predict the bubble radius and the relationship of the wall superheat degree and heat flux at OFV and ONB are obtained. Compared with the existing experimental data, the error distribution is more rational.Conclusion:The presented model can improve predicted results for distinguishing OFV and ONB under the limitation of experimental measuring equipment. However, more experimental data validation is necessary.  
        关键词：Bubble radius;ONB;OFV   
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        发布时间：2021-05-25
      • Jie HE,Xiaobin XIA,Jun CAI,Deng PAN,Yu PENG,Jianping HUANG,Guoqing ZHANG
        Vol. 39, Issue 4, Article number: 040601(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040601
        摘要：Background:Molten salt reactor is a fourth generation advanced reactor. The concrete wall is the key part of this high-temperature reactor shielding, so temperature field analysis is important.Purpose:This study attempts to calculate the temperature field of the TMSR-LF1(2-MW liquid-fueled molten salt experimental reactor) shielding, and judge if it meets the design requirements.Methods:In accordance with the problem that MCNP(Monte Carlo N Particle Transport Code) results cannot be directly imported into Fluent, a program which converts MCNP results to the spatial distribution of power density, and imports the spatial distribution of power density into the Fluent in the form of User-Defined Function(UDF) was developed by using Python programming language to realize the coupling of the two. According to TMSR-LF1 design parameters, a one-eight physical and thermal model of the whole reactor is established, using code MCNP and Fluent. Reactor radiation shielding thermal analysis adopts the assumptions that the different environment temperatures are 5℃, 18℃, 25℃, 30℃, 35℃ and 40℃, respectively.Results:The maximal values of temperature and temperature gradient in the radiation shielding concrete wall are 67.42℃ and 78.40℃·m-1, which are lower than limit values.Conclusion:The radiation shielding concrete wall can meet the design requirements.  
        关键词：MCNP;Fluent numerical analyses;Molten salt reactor   
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        发布时间：2021-05-25
      • Shuangyuan FENG,Yingying LI,Yi YU,Xianghui YIN,Jia FU,Bo LYU,Huajie WANG,Jun CHEN,Ruijie HU,Minyou YE
        Vol. 39, Issue 4, Article number: 040602(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040602
        摘要：Background:Charge-exchange spectroscopy is a powerful diagnostic tool for determining ion temperatures and rotational velocities in tokamak plasmas. This technique depends on detailed understanding of the atomic physics processes that affect the measured apparent velocities with respect to the true ion rotational velocities.Purpose:The study aims to give correction to Charge eXchange Recombination Spectroscopy(CXRS) measurement with Experimental Advanced Superconducting Tokamak(EAST) because of energy dependence of the charge-exchange cross-sections.Methods:Kinetic theory and numerical approximation of cross-section effects are usually used to evaluate the associated corrections. On EAST, kinetic theory and numerical approximation of cross-section effects will be applied to calculate the corrections.Results:A direct comparison between kinetic theory and numerical approximation of cross-section effects will be given. And kinetic theory is applied to give correction to the CXRS measure data in 2015.Conclusion:The correction results showed that two ways are feasible and charge-exchange cross-section effect has more influence on rotational velocity. It gives a possible way for the CXRS data correction because of charge-exchange cross-section effect.  
        关键词：Tokamak;CXRS;Ion temperature;Rotation velocity;Cross-section effect   
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        发布时间：2021-05-25
      • Shiwei SHAO,Kai WANG,Shixiang QU,Zhaozhong HE,Kun CHEN
        Vol. 39, Issue 4, Article number: 040603(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040603
        摘要：Background:The driving force and resistance in nitrate natural circulation loop(NNCL) are almost in the same magnitude. The system performance of NNCL can be influenced by lots of parameters, such as environment, material, structural and operation condition, thus selection of key parameters affecting NNCL is very important.Purpose:The aim is toidentify the key parameters affecting NNCL reliability.Methods:The analytic hierarchy process(AHP) is an effective method to analyze the importance of each parameter to the NNCL reliability using experts' judgment to structure judgment matrix and calculate the parameters' weight. In this paper, an AHP model and judgment matrix is established for the 40 parameters.Results:12key parameters are selected including physical parameters, structural parameters and operating parameters.Conclusion:The results show that the most important parameters affecting NNCL reliability are air temperature, heating power and air flow rate in the NNCL operational phase.  
        关键词：Nitrate salt;Natural circulation;Analytic hierarchy process;Key parameters   
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        发布时间：2021-05-25
      • Hongfei LIU,Binhang ZHANG,Shu ZHANG,Guangyao SUN,Lijuan HAO,Jing SONG,Pengcheng LONG
        Vol. 39, Issue 4, Article number: 040604(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040604
        摘要：Background:A full core Hoogenboom benchmark reactor model was proposed by Hoogenboom and Martin to monitor the increase in performance of Monte Carlo calculations of a full-size power reactor core over the coming years.Purpose:The correctness and computing performance of SuperMC(Super Monte Carlo Simulation Program for Nuclear and Radiation Process) was tested.Methods:Thekeffand power distribution were calculated and compared with MCNP(Monte Carlo N Particle Transport Code), and parallel efficiency was analyzed.Results:The SuperMC calculation results agreed well with those of MCNP, with the parallel efficiency reaching up to 98.7% by using 640 processors.Conclusion:Testing results validated the accuracy and efficiency of SuperMC in full reactor core calculation.  
        关键词：SuperMC;Monte Carlo;Hoogenboom benchmark;Full reactor core   
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        发布时间：2021-05-25
      • Jianping ZHU,Feng XIAO,Xilong GAO,Huanwen LYU,Lan LI
        Vol. 39, Issue 4, Article number: 040605(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040605
        摘要：Background:Currently, the computational model used to airborne radioactive source terms is too simple to applying to all cases.Purpose:The aim is to build a computational model for airborne radioactive concentration in fuel handling area and to study the influence factor of airborne radioactive source term thus to decrease occupational exposure dose.Methods:This paper constructed a computational model of airborne radioactive concentration in fuel handling area. Variations of typical radionuclide were analyzed. Then, we studied the effluences of radionuclide types, ventilation flow on airborne radioactive concentration and the main sources of radioactivity.Results:The maximum values of airborne radioactive concentration for all radionuclides during refueling should be treated as design values instead of the values at a certain moment or at the end of refueling. There is an inverse relation between the ratio of ventilation flow to net volume of fuel handling areaλhand airborne radioactivity concentration, the radioactivity in reactor coolant is the main source of airborne radioactivity.Conclusion:Adjusting ventilation flow, reducing radioactivity in coolant and decreasing evaporation are the main ways to reduce airborne radioactivity.  
        关键词：Airborne radioactivity;Calculation model;Ventilation flow;Radioactivity sources   
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        发布时间：2021-05-25
      • Linyuan KUANG,Liangang ZHENG,Dongchuan SU,Donghui WANG,Yingxue SUN
        Vol. 39, Issue 4, Article number: 040606(2016) DOI: 10.11889/j.0253-3219.2016.hjs.39.040606
        摘要：Background:The appearance of smooth pit defect brings considerable difficulties to the prediction of fatigue life of structure whilst the traditional approach of fatigue analysis hardly meets the requirements of engineering applications.Purpose:This study aims to find a fast approach for fatigue life estimation of structure with pit defeat for engineering applications.Methods:Based on Miner linear cumulative damage rule, the quantitative relation between usage factor of structure with pit defect and that of structure without pit defect is determined. Based on the data fitting of theS-Ncurve, the expressions of ratio of the permissible number of cycles are deduced, and the range of application is given for common materials of nuclear pressure vessel.Results:Computional results using above mentioned approach provide the codomain of undetermined constants and sphere of application.Conclusion:The approach for fatigue life estimation of structure with pit defect meets the requirements of engineering applications, thus is suitable to fast estimation of fatigue life for nuclear pressure vessel.  
        关键词：Pit defect;Fatigue life;S-N curve;Power function;Three parameter function   
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