分类： 物理学 >> 核物理学 提交时间： 2025-07-03
Zhang, Mr. Ze-Kun
han, Miss rui
Chen, Prof. Zhi-Qiang 陈志强
Tian, Dr. Guoyu
Liu, Dr. Bing-Yan
Zhang, Dr. Xin
Sun, Dr. Hui
Li, Mr. Qin
Zhang, Dr. Peiyan Zhang Peiyan
Shi, Mr. Fudong
Guo, Mr. Rui
摘要： The neutron yields induced by 500 MeV/u 4He ions bombarding a thick uranium target have been measured by the time-of-flight method at Heavy Ion Research Facility in Lanzhou. Simulations employing three Monte Carlo codes, GEANT4, FLUKA, and PHITS, were performed to calculate neutron yields under conditions identical to the experiment. The results indicate that all three codes reproduce key features of the experimental energy spectrum distribution to varying degrees, though each exhibits distinct advantages and limitations across specific energy intervals and spatial angles. This study provides critical data for optimizing the spallation target and subcritical reactor designs in accelerator-driven subcritical systems.
分类： 核科学技术 >> 辐射物理与技术 提交时间： 2024-12-29
摘要： 64Cu是一种重要的可实现诊疗一体化的医用同位素，国家八部委联合发布的《医用同位素中长期发展规划(2021-2035年）》明确指出其应用前景广阔。目前我国64Cu制备及生产水平与国际尚存在较大差距。为优化64Cu生产用同位素靶的设计，本文利用FLUKA程序，通过控制变量法，从辐照能量(5-70MeV)、辐照时间(4-72h)、冷却时间(0-390h)以及制备过程中部分相关杂质核素等方面，对使用质子束流轰击68Zn及64Ni靶制备64Cu进行了研究。结果表明，68Zn和64Ni靶较优辐照能量分别为35和15MeV；较优辐照时间均为36h；68Zn靶较优冷却时间为4h，而64Ni靶辐照后需尽快分离纯化；68Zn靶辐照过程中会产生67Cu，与64Cu可形成核素对,而64Ni靶不会；两种靶材辐照后都会产生65Ni、3H及56Mn等杂质核素；综合考虑加速器性能要求、64Cu产额以及放射性原子核纯度等因素，在制备64Cu时64Ni靶优于68Zn靶。相关研究结果为使用质子加速器制备64Cu的同位素靶设计提供了参考。
分类： 化学 >> 核化学 提交时间： 2024-07-11
摘要： 医用放射性核素99mTc广泛应用于SPECT显像，其主要来源于母核99Mo衰变。占全球99Mo供应量90%的五座反应堆将陆续停堆，99Mo面临不能稳定供应的情况，使用质子加速器照射100Mo靶生产99Mo和99mTc成为重要的补充手段。一些科研人员使用蒙特卡罗软件FLUKA模拟计算放射性核素的产额并发现计算结果与实验测量结果存在差异。为检验FLUKA能否正确模拟质子照射100Mo靶生成99Mo和99mTc，本文计算了FLUKA所使用的激活函数并与多个数据库及核反应程序TALYS计算结果相比较，提出了一种结合FLUKA和其它数据库激活函数计算产额的方法，使用不同的激活函数计算了质子照射100Mo靶并冷却一段时间后99Mo和99mTc的产额。结果表明FLUKA计算99Mo产额偏小，约为使用TENDL2023激活函数计算结果的59%-67%；99mTc产额偏大，约为使用TENDL2023激活函数计算结果的245%-260%。差异来源于FLUKA的质子-核反应截面与其它数据库存在较大区别且FLUKA无法正确处理不同激发态核素的产生。
分类： 核科学技术 >> 核探测技术与核电子学 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： A spherical tissue equivalent proportional counter (TEPC) for neutron monitoring has been developed. It was properly designed to produce a uniform electric field intensity around the anode wire. An internal 241Am alpha source was adopted for lineal energy calibration. The TEPC was characterized in terms of dose equivalent response in a standard 252Cf neutron field, and was tested with 2.45 MeV neutrons. Microdosimetric spectra, frequency mean lineal energy and dose-average mean lineal energy of 2.45 MeV neutrons were obtained and compared with FLUKA Monte Carlo simulation results. The measurement and simulation results agreed well. The mean quality factor and dose equivalent values evaluated from the 2.45 MeV neutron measurement were in good agreement with the recommended effective quality factor and ambient dose equivalent H*(10)(10), respectively. Preliminary results have proved the availability of the developed TEPC for neutron monitoring.
分类： 核科学技术 >> 核探测技术与核电子学 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： The gamma-ray linear and the mass attenuation coefficients of Pb, Al, Cu, and plexiglass materials were calculated from both experimental and theoretical (simulation) methods. For the experimental results, a spectrometer, which was consisted of a NaI(Tl) inorganic scintillation detector, was used. The theoretical attenuation values were calculated by means of the FLUKA Monte Carlo (MC) and XCOM programs. Obtained attenuation coefficients from the experiment and the theoretical methods were compared with each other and literature values.
分类： 核科学技术 >> 裂变堆工程技术 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： Radiation shielding structure for C-ADS Inject-I was designed and optimized using FLUKA code. For this equipment was planned to be established in an existing tunnel hall and installed in limited space, several shielding hot spots are re-designed and analyzed respectively as they may cause radiation dose leakage and weakening of the total shielding effect. Besides, some new shielding structures are applied in the simulation process. All designed shielding structures are discussed in this paper and the results will meet the governmental criteria for radiation protection.
分类： 核科学技术 >> 粒子加速器 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： Induced radioactivity is one of the essential problems in the radiation protection field of proton accelerators. Research on the induced radioactivity of low-energy proton accelerators is highly limited. Given such context, this study investigates the cross section of 63Cu (p, n) 63Zn and 65Cu (p, n) 65Zn in Cu targets at 11 MeV proton accelerators through an activation experiment. The uncertainties of the results are analyzed in detail. Results show that the cross section of the reaction of 65Cu (p, n) 65Zn in the experiment is only 1.36% lower than that of the FLUKA simulation, whereas the reaction of 63Cu (p, n) 63Zn in the experiment is 25.4% higher than that of the FLUKA simulation. Given that the benchmark for the FLUKA code of low-energy proton accelerators is very limited, this study provides a reference in this field.
分类： 核科学技术 >> 裂变堆工程技术 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： This work determined a new M-C code (FLUKA) that can be used to calculate the dosimetric characteristics of seed sources. Dosimetric parameters (dose rate constant, radial dose function, and anisotropy function) of model 6711 125I seed source were calculated with FLUKA. The results were compared to the relative data recommended by AAPM TG43U1: dose rate constant with FLUKA was in agreement with 2.041%; radial dose functions with FLUKA for distances ranging from 0.5 cm to 10 cm, the deviation was less than 5%. Therefore the FLUKA code can be used to calculate the dosimetric characteristics of seed sources.
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