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质子入射散裂产物理论研究方法探讨   总被引:1,自引:1,他引:0  
简要介绍了几种关于中高能质子入射引起散裂反应产物理论计算的方法,以及这些方法的最新发展.比较了这些方法在理论计算中的特点,指出经典外推方法有局限性,量子分子动力学方法和改进后的M C方法的计算结果与实验数据有较好的符合,但是计算量大,而且量子分子动力学方法在与宏观输运理论连接上存在不少的困难.半经验计算方法已经取得了初步的成果,需要根据新的实验结果来对其进行发展. The analysis on spallation product of proton-induced reaction with intermediate energy has important applications, such as astrophysics, biophysics, spallation neutron source, and accelerator-driven system (ADS) etc. In recent year, some theoretical models have been developed to investigate this reaction processes. At present work, we introduce the extrapolated classic theory, the quantum molecule dynamic (QMD) plus statistical decay and fission models, the method of Mento-Carlo and Smiempirical method for...  相似文献   
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多步动力学模型(MSDM)研究中、高能质子引起的散裂反应分为3个过程:核内级联、粒子预平衡发射以及通过蒸发粒子和裂变方式的剩余激发核退激发过程.利用Ignatyuk能级密度公式代替MSDM模型中的费米气体能级密度公式,改进其研究质子入射引起散裂产物的形成截面.采用Ignatyuk能级密度公式MSDM研究p+208Pb散裂产物的电荷、质量分布以及产物核形成截面,结果很好地再现了实验数据,且比利用费米气体能级密度的MSDM结果好得多. The level density of Ignatyuk formula is introduced into the Many stages dynamics model ( (MSDM)) instead of Fermi-gas formula to improve the simulation of spallation fragments. The results of (MSDM) with Ignatyuk formula reproduced the experimental data well for the mass and charge distributions, the formation cross sections of isotopic product of proton-induced spallation on~(208)Pb. The calculations are in agreement with the experimental data and better than some simulations by MSDM with Fermi-gas ...  相似文献   
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在En≤20MeV的情况下,忽略了粒子的二次发射过程,认为复合系统的形成截面是能量相关的,得到了理论模型清晰、公式形式简单的半经验计算方法.在靶核23≤A≤209的范围内,利用大量(n,p)和(n,α)反应的截面实验数据对可调参数进行了研究,得到了参数对靶核的N和Z以及入射能量的依赖关系.对得到的参数做了定性的解释,利用普适参数对(n,p)和(n,α)反应的激发函数做了预言,预言值在其误差范围内与实验数据一致. To simplify the calculation, some assumptions are considered at present work. The preequilibrium emission is the first step in the equilibrium process, which is characterized by exciton n=3 and "never come back" are considered at the preequilibrium emission process; the proton and alpha emissions are only competed with the neutron emission, the second particle emission is neglected. A semiempirical method of the cross section for (n, p ) and (n, α) reactions were obtained on the basis of evaporatio...  相似文献   
4.
简要分析了质子入射核反应的半经验研究方法,指出半经验研究方法应该建立在独立产额数据之上,而目前半经验研究方法主要是建立在以往的累积产额数据之上.通过对最新的实验得到的独立产额数据并结合MSDM的计算结果的分析,发现描述散裂质量分布的参数应该分为与能量有关和无关两个部分,并指出这与快过程平衡时间的不同有关. We analyzed the former solution of semi-empirical methods, which is first funded by G. Rudstam. On this basis, we pointed out that all the former solutions are basically based on so-called cumulative reaction data not on independent data. On the analysis of newly data measured by GSI, we founded that mass distribution of spalltion production could be divided to two parts: one is independent on induced-energy, but on the mass number of target; one is dependent on energy. Also, we argued that such...  相似文献   
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樊胜  阎芳  张鸿洲  赵志祥 《中国物理 C》2003,27(11):1009-1014
基于核反应蒸发模型和预平衡激子模型,在一些近似条件下得到了入射能量小于20MeV的(n,p)的激发函数解析半经验表达式,靶核在23≤A≤209的范围内,利用大量(n,p)反应的截面实验数据对可调参数进行了研究,得到了参数对靶核的N和Z以及中子入射能量的依赖关系,对得到的参数做了定性的解释,利用普适参数对(n,p)反应的激发函数做了预言,预言值在其误差范围内与实验数据一致。  相似文献   
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