最新刊期
卷 44 ， 期 5 ， 2021
- “在宇宙射线响应测量领域，专家利用辐射检验场测量计算辐射测量仪的宇宙射线响应和校准系数，为确定辐射测量仪的宇宙射线响应值和校准系数提供解决方案。”摘要：BackgroundMeasurement of radiation environment γ dose rate is greatly influenced by the high energy charged particles of cosmic rays which varies in different inspection sites. Different types of radiometers are affected differently due to the different cosmic ray response and calibration coefficient.PurposeThis study aims to verify the feasibility of the terrestrial measuring method for cosmic ray response and calibration coefficient of radiometer.MethodsFirst of all, calculation of cosmic ray response and calibration coefficient of radiometer by radiation test field measurement was proposed, then, two types of radiometer 6150AD and RSS-131 were employed to measure radiation field at two different γ dose rate levels. Repeat measurements were performed using the same radiometers at short intervals (4 days) to investigate the repeatability of measurement fitting results. Finally, four types of radiometer, i.e., RSS-131, 6150AD, BH3103 and RED-100, 14 sets in total γ radiometers, were used in both radiation inspection field and one test site of WanLv lake (in Guangdong province) for comparison and verification.ResultsMeasured results at radiation test field show that best cosmic ray response transfer effect is achievable between the same type of radiometers in the low dose rate with maximum dose rate less than 500 nGy·h-1. Experimental results of 11 radiometers of four types show that cosmic ray response values obtained by the calculation method determined by experiments, are basically consistent with the actual measured values of the same radiometer in Wanlv lake, and the relative deviation between the calibration coefficient determined by this method and the effective calibration coefficient of the radiometer is within 10%.ConclusionsThe terrestrial measurement method can replace the actual measurement to determine the cosmic ray response and calibration coefficient of the radiometer.关键词：Radiation inspection field;Radiation measuring instrument;Cosmic rays;Calibration coefficient
- 495
- |
- 45
- |
- 0
发布时间：2024-10-25
SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS
- “中国散裂中子源研制费米斩波器样机，模拟验证了三种狭缝包设计方案的可行性，为非弹性散射谱仪费米斩波器中子狭缝包设计提供参考。”摘要：BackgroundFermi chopper is the key equipment for monochromating the neutron beam in an inelastic neutron scattering spectrometer, and its performance will affect the resolution and counting rate of the spectrometer. The core component of Fermi chopper is neutron slit package, which is composed of neutron absorbing material and transparent material, and selects multiple single wavelength pulsed neutrons by high-speed rotation.PurposeThe study aims to design suitable slit packages for Fermi chopper prototype of China spallation neutron source (CSNS).MethodsAccording to the common experimental conditions of inelastic scattering, the development target of the Fermi chopper prototype was determined, then three typical slit packages were designed, and the feasibility of the design was verified by MCStas software simulation.ResultsThe simulation results show that: (1) the three kinds of slits can achieve a resolution of 2%~10% in the wavelength range of 0.02~0.50 nm, and the neutron decay rate and the slit packet transmittance meets the requirements; (2) the optimal incident wavelengths of the three kinds of slit packets at 600 Hz operating frequency are 0.165 nm, 0.040 nm and 0.023 nm respectively, which can be used in different wavelength ranges; (3) in the long wavelength band with better resolution, the slit packet can be used to reduce the velocity and improve the neutron pass rate.ConclusionsThe physical parameters for the prototype development of CSNS Fermi chopper are given by this study, it provides a reference for the slit package performance test of the future prototype, as well as the design of the neutron slit package of the Fermi chopper of the inelastic scattering spectrometer.关键词：Fermi chopper;Slit package;Monochromatic neutron;Resolution;Neutron pass rate
- 382
- |
- 37
- |
- 0
发布时间：2024-10-25 - “CiADS加速器装置核物理实验终端提出单束团需求，通过计算与模拟，在低能传输段筛选出6.15 ns单束团，实现整体传输效率43.9%。”摘要：BackgroundThe nuclear physics experiment terminal of the China initiative accelerator driven system (CiADS) accelerator device requires a single bunch. The frequency of radio-frequency quadrupole (RFQ) accelerator of CiADS facitily is 162.5 MHz, so the pulse width of a single bunch is 6.15 ns. Due to the falling edge width of the conventional constant voltage Chopper is close to 20 ns, the 6.15 ns field-free area cannot be achieved.PurposeThis study aims to develop a new method to select a single bunch before RFQ to facilitate the superconducting linear accelerator of CiADS.MethodsUnder the premise of without changing the physical size of the deflector and the beam line layout in the low energy section of the beam chopper, a linearly alternating positive and negative voltage applied to the deflector plate of the chopper at CiADS prototype II was implemented to select a single bunch. The pulse alternating high voltage demand for 6.15 ns single bunch was calculated, and applied to the simulation software Tracewin to verify its performance.Results & ConclusionsSimulation results indicate that the voltage change slope needs to be 201.8 V·ns-1 for a 20 keV proton beam, so that a 6.15 ns single bunch can be selected. At the same time, the multi-particle simulation results show that the transmission of the low energy beam transport line (LEBT) is 80.7%, the RFQ transmission is 54.4%, and the overall transmission is 43.9%.关键词：Single bunch;Chopper;Transmission efficiency;Radio-frequency quadrupole
- 378
- |
- 29
- |
- 0
发布时间：2024-10-25 - “上海硬X射线自由电子激光装置的超导射频腔需高精度射频低电平系统稳定腔场幅度和相位。为解决腔体失谐问题，引入自激励控制系统，开发数字模拟腔验证设计算法，确保腔场幅度稳定，减少反射电压。”摘要：BackgroundA high precision low-level radio-frequency (LLRF) system for a superconducting radio-frequency (RF) cavity of Shanghai high-repetition-rate X-ray free-electron laser and extreme light facility (SHINE) is required to stabilize the electromagnetic field of cavities. However, due to the high loaded quality factor of the 1.3 GHz continuous-wave superconducting RF cavity, the RF cavity has a small electromagnetic bandwidth in the frequency domain. The small electromagnetic frequency mismatch between the RF power source and RF cavity can easily interlock in the generator driven resonator control system.PurposeThis study aims to develope a LLRF and a digital RF cavity simulator ensure stable electromagnetic field of 1.3 GHz continuous-wave superconducting RF cavities.MethodsA self-excited loop (SEL) control system was developed to prevent interlock, and a generator driven resonator (GDR) control system was developed to operate the RF cavity under normal working states. In addition, a digital RF cavity simulator was developed to verify the design algorithms of the LLRF system. The SEL/GDR system and RF cavity simulator were also implemented and tested based on MicroTCA.4 platform.ResultsIn the free SEL mode, the amplitude of the cavity RF field is stable at the set-point, even if the cavity is detuned for several half-bandwidths. In the locked mode, the stability of the cavity RF field in the amplitude and phase are 0.458 0% (Root Mean Square, RMS) and 0.058° (RMS) respectively, at the detuning frequency of 5 Hz.ConclusionsIt is verify that the SEL control system can stabilize the cavity RF field even when the cavity is detuning, and the cavity simulator proves to be a reliable platform for the evaluation of new algorithm.关键词：Digital RF cavity simulator;High-repetition X-ray free-electron laser;Low-level RF system;Self-excited loop;System generator
- 402
- |
- 30
- |
- 0
发布时间：2024-10-25
ACCELERATOR, RAY TECHNOLOGY AND APPLICATIONS
- “中国实验快堆放射性钠气溶胶监测仪校准方法研究，为监测仪量值溯源提供解决方案。”摘要：BackgroundLiquid metal sodium is used as coolant in China Experimental Fast Reactor (CEFR), the radioactive sodium aerosol in primary loop cold trap process needs to be monitored, so that the corresponding protective measures can be taken in time to ensure the health and safety of the staff. To ensure the accuracy of the monitoring results, it is necessary to calibrate the radioactive sodium aerosol monitor regularly.PurposeThis study aims to propose an effective method for the calibration of radioactive sodium aerosol monitor.MethodsA special radioactive aerosol membrane source was designed and applied to calibrating the radioactive sodium aerosol monitors. The response, relative error, and repeatability of the monitor were studied separately, and the uncertainty of the calibration factor was evaluated.ResultsThe results show that the uncertainty of response factor is 5% (k = 2).ConclusionsThis calibration method is suitable for the calibration of radioactive sodium aerosol monitors, and meets the requirements for traceability of the monitors.关键词：Sodium aerosol;Standard γ source;Calibration technology of monitor
- 368
- |
- 30
- |
- 0
发布时间：2024-10-25 - “在X射线天文望远镜领域，中国科学院高能物理研究所设计了一种X射线二次多靶源装置，为软X射线探测器的前期电子学联调和测试提供解决方案。”摘要：BackgroundEinstein Probe (EP) and enhanced X-ray Timing and Polarimetry (eXTP) are two kinds of X-ray focusing telescopes recently proposed. Calibration and the joint test with back-end electronics of the Follow-up X-ray Telescope (FXT) onboard EP satellite and the Spectroscopy Focusing Array (SFA) onboard eXTP satellite, use high-purity n-type silicon CCD (pnCCD) detector and Silicon Drift Detector (SDD), respectively. The joint debugging of electronics and calibration are carried out at the calibration hall of the Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, where the X-ray target sources are indispensable part of the work.PurposeThis study aims to design a X-ray secondary multi-target (XSMT) as the soft X-ray source for joint debugging and calibration of above work.MethodsThe bremsstrahlung photons produced by the electronic shooting of the X-ray machine to hit the secondary target was made use of to emit the X-ray fluorescence lines with the interaction of bremsstrahlung photons and target atoms. The parameters such as diameter of the collimator, high voltage of X-ray machine and material of the inner wall were simulated by Geant4. Then, the spectrum was measured by pnCCD and SDD, and the spot size of XSMT was analyzed by pnCCD.Results & ConclusionsThe spectrum of XSMT shows that the device can produce X-ray signals with high signal-to-noise ratio, and several fluorescence lines are obtained by changing the various targets. It can meet the requirements of the detector and back-end electronics test. Furthermore, it can be widely used in the pretest of soft X-ray detector.关键词：Einstein probe;Enhanced X-ray timing and polarimetry;Electronic joint debugging;Calibration;X-ray secondary multi-target source
- 735
- |
- 38
- |
- 0
发布时间：2024-10-25 - “康普顿相机技术在天文观测、医学成像等领域取得新进展，为相关研究提供新方向。”摘要：Compton camera (CC) is a new type gamma-ray imaging modality. Because CC has no mechanical collimation structure, it has unique advantages in detection efficiency compared with other gamma-ray imaging modalities. Due to these advantages, Compton camera system is well applied in many fields, such as astronomical observation, medical imaging, environmental radiation monitoring, proton therapy and so on. With the development of emerging detector technology and electronics technology, Compton camera systems have been continuously optimized from scintillator detectors to high-performance semiconductor detectors. Moreover, except for traditional dual-layer detector structure Compton camera, new structures have also been proposed, such as "separate" structure and "integrated" structure. In this paper, the imaging principle, reconstruction algorithm and key factors affecting the performance of Compton camera, as well as the latest development of Compton cameras worldwide, are investigated and summarized. The imaging angular resolution of state-of-the-art Compton cameras generally reaches several degrees, and the spatial resolution reaches the order of 1 mm.关键词：Compton camera;Medical imaging;Angular resolution
- 432
- |
- 151
- |
- 0
发布时间：2024-10-25
NUCLEAR ELECTRONICS AND INSTRUMENTATION
- “在材料科学领域，研究人员采用多种表征技术，分析了低能氢离子辐照对多晶钨材料表面损伤的影响，为理解其表面刻蚀机制提供了重要参考。”摘要：BackgroundMetal tungsten (W) has a high melting point, low hydrogen solubility and high thermal conductivity. Therefore, it has been selected as one of the most promising plasma-facing materials for the future international thermonuclear experimental reactor (ITER).PurposeThis study aims to investigate the etching process of polycrystalline W induced by low energy hydrogen ion irradiation.MethodsPolycrystalline W materials were irradiated with 130 eV hydrogen ions. The irradiation damage behavior of W was researched by scanning electron microscopy (SEM), conductive atomic force microscopy (CAFM), Energy Dispersive Spectrometer (EDS) and nano indentation.ResultsThe investigates show that when the irradiation dose of H ions increases from 1.0×1024 ions∙m-2 to 1.5×1025 ions∙m-2, the surface of W material experiences a periodic evolution process from forming bubbles with H aggregation, the bubbles becoming bigger at grain boundaries, and gradually diffusing to the grain surface, until the W surface layer falls off due to the rupture of H bubbles. The irradiation dose required for one period of evolution is about (6.0~8.0)×1024 ions∙m-2. Nano indentation measurements show that the surface hardness of W material decreases after H ion irradiation. No impurities, especially elements of C and O, are detected on the W surface by EDS.ConclusionsIt is verified that the evolution of the unstable damage layer on the W surface induced by irradiations of low energy H ion is the main reason for the etching of W material. This work is very important for further understanding of the etching mechanism of W surface induced by H ion irradiation under the condition that the energy of irradiated H ion is lower than the sputtering threshold energy.关键词：Plasma;Tungsten;H ions irradiation;H bubble;Erosion
- 370
- |
- 29
- |
- 0
发布时间：2024-10-25 - “在辐射效应领域，研究了双极运算放大器电离总剂量与单粒子瞬态的协同效应，为提高其抗辐射性能提供解决方案。”摘要：BackgroundBipolar devices used in space radiation environment for a long time are simultaneously threatened by the total ionization dose (TID) effect and single event transient (SET), and there is a synergistic effect between TID and SET. The enhanced low dose rate sensitivity (ELDRS) effect unique to bipolar devices may affect the synergistic effect.PurposeThis study aims to investigate the physical mechanism of TID's impact on the SET in bipolar operational amplifier LM158.MethodsFirst of all, the LM158 samples were irradiated by 60Co γ-ray of a high dose rate of 0.1 Gy·s-1(Si) and a low dose rate of 1×10-4 Gy·s-1(Si). Then, the heavy ion (Tantalum) irradiation test was performed after the total dose was accumulated to 1 000 Gy(Si). The output single event transients of irradiated LM158 were observed by oscilloscope, and all the collected SETs were saved in computer and processed by MATLAB programming.ResultsThe experimental results show that the TID of bipolar operational amplifier LM158 causes the SET pulse amplitude to decrease and pulse width to expand. At the same time, compared with the high dose rate irradiation condition, the SET pulse width of LM158 is expanded by 50% under the low dose rate irradiation condition.ConclusionsThe study indicates that the interface trap charge accumulated in the bipolar transistor is the fundamental reason for the synergistic effect of TID and SET.关键词：Bipolar operational amplifier;Total ionization dose;Single event transient;Synergistic effect
- 364
- |
- 27
- |
- 0
发布时间：2024-10-25
NUCLEAR PHYSICS, INTERDISCIPLINARY RESEARCH
- “在核能领域，研究人员开发了ARES-MACXS模块，用于精确计算多群截面，为聚变和裂变装置屏蔽提供可靠数据。”摘要：BackgroundDeterministic method is widely used in shielding calculation for fusion and fission devices. The data accuracy of multi-group cross section has significant influence on the deterministic calculation results.PurposeThis study aims to obtain a multi-group cross-section library suitable for various shielding problems by developing a multi-group cross-section processing code ARES-MACXS based on Bondarenko resonance processing method with functionalities of resonance processing, temperature interpolation, transport correction, up-scattering processing, collapse group, and so on, and uses the exponential interpolation method to obtain more accurate multi-group cross sections.MethodFirst of all, KASHIL_E70 library and FENDLL-3.1d library were respectively processed by ARES-MACXS for single nuclide calculation to verify the correctness of the code, and the results were compared with continuous energy Monte Carlo code. Then, the ill-Fe, OKTAVIAN-Al and other benchmarks were calculated to verify the applicability of the code to different nuclides, and the results were compared with the continuous energy Monte Carlo code. Finally, the ill-Fe, OKTAVIAN-Al and other benchmarks calculated by ARES-MACXS were compared with experimental measurements.ResultsThe error between the deterministic transport calculation result and the Monte Carlo calculation result is less than 1%, the error between the deterministic transport calculation result and experimental measurement values is less than 20%.ConclusionsThe results show that the multi-group cross sections calculated by ARES-MACXS have reliable accuracy and can be applied to the verification of benchmarks, hence can be applied to the calculation of engineering problems.关键词：Shielding calculation;Multi-group cross-section;MATXS;Resonance self-shielding
- 356
- |
- 31
- |
- 0
发布时间：2024-10-25 - “在核能领域，专家通过实验研究了矩形通道局部变形堵塞下的对流传热现象，修正齐德-泰特公式，提高了传热计算精度。”摘要：BackgroundThe surface bubbles of the plate-type fuel assembly can cause particle blockage accident in rectangular channel.PurposeThis study aims to investigate the convective heat transfer in a partially blockage rectangular channel by experiments.MethodsIn the range of Reynolds number 470~3 300, the convective heat transfer experiments were carried out under the conditions of case 1 with no bubble, case 2 with one bubble, case 3 with transverse three bubbles and case 4 with longitudinal three bubbles respectively. The average Nusselt number of the calculated results by the Sieder-Tate formula was compared with the experimental results. On the one hand, there was little calculation error between the calculated results and the experimental results in the cases with no bubble. On the other hand, there were large errors in the cases with local blockage of bubbling. Hence the Sieder-Tate formula was modified to re-calculate the average Nusselt number in above four cases.ResultsThe maximum error of prediction on convective heat transfer of the modified formula in case 2 is reduced from 35.4% to 19.8%. The maximum error of prediction on convective heat transfer of the modified formula in case 3 is reduced from 38.5% to 21.3%. The maximum error of prediction on convective heat transfer of the modified formula in case 4 is reduced from 47.8% to 8.7%.ConclusionsThe modified formulas can more accurately calculate the convective heat transfer in rectangular channel with partial blockage.关键词：Rectangular channel;Accident of blockage;Bubble;Convective heat transfer;Modify
- 369
- |
- 29
- |
- 0
发布时间：2024-10-25 - “在后处理厂乏燃料贮存水池，采用吊篮储存和转运乏燃料组件，提升转运能力，具有较好的安全性和经济性。针对国内商业核电站服役使用的典型乏燃料组件结构参数，设计了可一次性装载8盒乏燃料组件的储运吊篮。利用SuperMC软件对满载乏燃料组件的储运吊篮进行了临界安全分析，再利用ANSYS有限元软件对其进行抗震分析。临界安全分析结果表明：即使满载乏燃料组件的吊篮在无限大乏燃料贮存水池内紧密排列，贮存水池keff最高仅0.906；抗震分析结果表明：在0.3 g设计地震震动加速度下，吊篮最大结构应力为7.92 MPa，最大形变量为0.32 mm，不影响其功能。因此储运吊篮设计合理，可满足后处理厂乏燃料水池储运吊篮的基本安全要求。”摘要：BackgroundThe transportation capacity can be enhanced by using transfer basket in the spent fuel pool of a reprocessing plant. At the same time, the safety and economy of the spent fuel reprocessing can be reinforced by the transfer basket.PurposeThis study aims to design transfer basket for typical spent fuel assemblies in China.MethodsBased on the transfer requirements of spent fuel assembly in the reprocessing plant, the basket was designed to carry eight spent fuel assemblies as one time loading. Both criticality safety analysis and seismic analysis were carried out to evaluate the reliability of the basket by using SuperMC and ANSYS codes, respectively.ResultsThe results of criticality safety analysis show that the keff of the spent fuel pool is only 0.906 even if the baskets are closely arranged in the spent fuel pool. The results of seismic analysis show that the maximum stress of the basket is 7.92 MPa and the maximum deformation is only 0.32 mm under the seismic acceleration of 0.3 g.ConclusionsThe above results show that the structure of the basket is reasonable, and meets the basic safety requirements of the transfer basket of a reprocessing plant.关键词：Reprocess;Spent fuel;Basket;Fuel assembly
- 379
- |
- 37
- |
- 0
发布时间：2024-10-25 -
An adaptive DE algorithm and its preliminary application in intelligent design of space reactor AI导读
“在空间堆结构优化设计领域，专家提出了自适应差分进化算法，优化Kilopower空间堆模型，降低堆芯质量38.2%。”摘要：BackgroundThe space reactor has broad application prospects, and its structure optimization design has an extremely high economic and technical application value. Due to the high coupling degree of variables and complex design in the optimal design of the space nuclear reactor structure, the manual solution process is inefficient and time-consuming, and the optimal solution is hard to achieve.PurposeThis study aims to propose an optimal algorithm for structure design of space reactor.MethodsAn adaptive differential evolution (DE) algorithm based on the classic DE algorithm was proposed. The strategy of balancing global and local search capabilities by dynamically adjusting the control parameters was adopted to enhance the algorithm optimization ability. Finally, with structural parameters as variables and the core quality as objective function the Kilopower reactor model with a thermo power of 4.3 kW was optimized, and the neutron transport was calculated by combing the neutron transport design and safety evaluation software SuperMC simultaneously.ResultsThe core quality of the optimized space reactor was reduced by 38.2% when the design requirements were met.ConclusionsThe correctness and effectiveness of the adaptive DE algorithm proposed in this paper are verified in the design of space reactor core.关键词：Differential evolution algorithm;Adaptive;Core optimization;Kilopower- 353
- |
- 27
- |
- 0
发布时间：2024-10-25
NUCLEAR ENERGY SCIENCE AND ENGINEERING
- Address：2019 Jialuo Road, Jiading, Shanghai, China Postal code：201800
- Tel：021-39194977 Email：LHB@sinap.ac.cn
- Technical support is provided by Beijing Founder electronics co., LTD 沪ICP备05005479号-1
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
- Total Visits：740143 Visits Today：885
0