【作者】 罗均华；

【导师】 孔祥忠；

【作者基本信息】 兰州大学 ， 粒子物理与原子核物理， 2008， 博士

【摘要】 用活化法以⁹³Nb（n,2n）^92mNb或²⁷Al（n,α）²⁴Na反应截面为中子注量标准,对d+T中子引起的铂同位素：¹⁹⁰Pt（n,2n）¹⁸⁹Pt、¹⁹⁶Pt（n,2n）^195mPt、¹⁹⁸Pt（n,2n）¹⁹⁷Pt、¹⁹⁸Pt（n, 2n）^197mPt、¹⁹²Pt（n,2n）¹⁹¹Pt、¹⁹⁴Pt（n,p）¹⁹⁴Ir、¹⁹⁵Pt（n, p）^195mIr和¹⁹⁶Pt（n,p）^196mIr等反应道；钌同位素：¹⁰⁴Ru（n,2n）¹⁰³Ru、⁹⁸Ru（n,2n）⁹⁷Ru、⁹⁶Rn（n,2n）⁹⁵Ru、⁹⁶Ru（n, p）^96gTc、⁹⁶Ru（n, p）^96mTc、¹⁰⁴Ru（n,p）¹⁰⁴Tc、¹⁰²Ru（n, p）^102mTc、¹⁰⁴Ru（n,α）¹⁰¹Mo、¹⁰²Ru（n,α）⁹⁹Mo、⁹⁶Ru（n,α）^93mMo和⁹⁶Ru（n, d）^95mTc等反应道;锶同位素:⁸⁴Sr（n,2n）⁸³Sr、⁸⁶Sr（n,2n）^85mSr、⁸⁶Sr（n,2n）^85gSr、⁸⁸Sr（n,2n）^87mSr、⁸⁴Sr（n,p）⁸⁴Rb、⁸⁶Sr（n,p）⁸⁶Rb、⁸⁸Sr（n,p）⁸⁸Rb、⁸⁸Sr（n,α）^85mKr等反应道;硒同位素:⁸²Se（n,2n）^81mSe、⁸²Se（n,2n）^81gSe、⁸²Se（n,2n）⁸¹Se、⁷⁶Se（n,2n）⁷⁵Se、⁷⁸Se（n,p）⁷⁸As、⁷⁶Se（n,p）⁷⁶As、⁷⁴Se（n,p）⁷⁴As和⁸⁰Se（n,α）⁷⁷Ge等反应道;砷同位素:⁷⁵As（n,2n）⁷⁴As、⁷⁵As（n, p）^75m+gGe和⁷⁵As（n,α）^72m+gGa三个反应道;锇同位素:¹⁹²Os（n,2n）¹⁹¹Os、¹⁸⁶Os（n,2n）¹⁸⁵Os、¹⁸⁴Os（n,2n）^183mOs、¹⁸⁴Os（n,2n）^183gOs、¹⁸⁴Os（n,2n）¹⁸³Os、¹⁹⁰Os（n,p）^190mRe、¹⁹⁰Os（n,p）^190gRe、¹⁹⁰Os（n,p）¹⁹⁰Re、¹⁸⁹Os（n,p）¹⁸⁹Re、¹⁸⁸Os（n,p）¹⁸⁸Re、¹⁹⁰Os（n,α）¹⁸⁷W和¹⁹⁰Os（n,n’）^190mOs等12个反应道;镥同位素:¹⁷⁵Lu（n,2n）^174mLu、¹⁷⁵Lu（n,2n）^174gLu和¹⁷⁵Lu（n,α）¹⁷²Tm等3个反应道,共计53个反应道130多个能量点对应截面进行了测量,在截面测量中样品均为高纯的天然同位素单质或化合物。在数据的测量中使用高分辨率的同轴高纯锗（HPGe）探测器进行γ谱的获取,利用成熟的截面计算公式进行了数据的处理,同时根据核反应生成核人工放射性的衰变和生长规律,得到了在核反应截面测量中扣除由EC或β^-衰变对所测量反应影响的计算公式、生成核相同时截面的计算公式以及在截面测量中监督反应的选择规则等在数据处理中要解决的问题。并把本工作的数据和其他一些作者的数据以及评价值进行了收集、分析和比较,其中¹⁹⁰Pt（n,2n）¹⁸⁹Pt、¹⁷⁵Lu（n,α）¹⁷²Tm、⁹⁶Ru（n,p）^96mTc和⁹⁶Ru（n,α）^93mMo四个反应截面值在我们是首次测量报道。在14 MeV中子引起的核反应截面测量的基础上,本文对2007年以前的14.5 MeV中子引起的（n,2n）、（n,p）、（n,α）、（n,t）、（n,³He）五种核反应截面的实验数据进行了收集、分析和整理。根据核反应蒸发模型和预平衡激子模型,在一定的近似条件下对这五种核反应截面系统学进行了研究,给出了计算14.5 MeV中子引起的上述五个反应截面的系统学公式,并与文献结果进行了比较。更多还原

【Abstract】 Cross-sections for ¹⁹⁰Pt（n,2n）¹⁸⁹Pt, ¹⁹⁶Pt（n,2n）^195mPt, ¹⁹⁸Pt（n,2n）¹⁹⁷Pt, ¹⁹⁸Pt（n, 2n）^197mPt, ¹⁹²Pt（n,2n）¹⁹¹Pt, ¹⁹⁴Pt（n,p）¹⁹⁴Ir, ¹⁹⁵Pt（n, p）^195mIr and ¹⁹⁶Pt（n,p）^196mIr reactions on platinum isotopes; for ¹⁰⁴Ru（n,2n）¹⁰³Ru, ⁹⁸Ru（n,2n）⁹⁷Ru,⁹⁶Rn（n,2n）⁹⁵Ru,⁹⁶Ru（n, p）^96gTc,⁹⁶Ru（n, p）^96mTc,¹⁰⁴Ru（n, p）¹⁰⁴Tc, ¹⁰²Ru（n, p）^102mTc,¹⁰⁴Ru（n,α）¹⁰¹Mo,¹⁰²Ru（n,α）⁹⁹Mo, ⁹⁶Ru（n,α）^93mMo and ⁹⁶Ru（n, d）^95mTc reactions on ruthenium isotopes; for ⁸⁴Sr（n,2n）⁸³Sr,⁸⁶Sr（n,2n）^85mSr,⁸⁶Sr（n,2n）^85gSr, ⁸⁸Sr（n,2n）^87mSr,⁸⁴Sr（n,p）⁸⁴Rb,⁸⁶Sr（n,p）⁸⁶Rb,⁸⁸Sr（n,p）⁸⁸Rb,⁸⁸Sr（n,α）^85mKr reactions on strontium isotopes; for ⁸²Se（n,2n）^81mSe, ⁸²Se（n,2n）^81gSe, ⁸²Se（n,2n）⁸¹Se, ⁷⁶Se（n,2n）⁷⁵Se, ⁷⁸Se（n,p）⁷⁸As, ⁷⁶Se（n,p）⁷⁶As, ⁷⁴Se（n,p）⁷⁴As and ⁸⁰Se（n,α）⁷⁷Ge reactions on selenuum isotopes; for ⁷⁵As（n,2n）⁷⁴As, ⁷⁵As（n, p）^75m+gGe and ⁷⁵As（n,α）^72m+gGa reactions on arseniic isotopes; for ¹⁹²Os（n,2n）¹⁹¹Os, ¹⁸⁶Os（n,2n）¹⁸⁵Os, ¹⁸⁴Os（n,2n）^183mOs, ¹⁸⁴Os（n,2n）^183gOs, ¹⁸⁴Os（n,2n）¹⁸³Os, ¹⁹⁰Os（n,p）^190mRe, ¹⁹⁰Os（n,p）^190gRe, ¹⁹⁰Os（n,p）¹⁹⁰Re, ¹⁸⁹Os（n,p）¹⁸⁹Re, ¹⁸⁸Os（n,p）¹⁸⁸Re, ¹⁹⁰Os（n,α）¹⁸⁷W and ¹⁹⁰Os（n,n’）^190mOs reactions on osmium isotopes, and for ¹⁷⁵Lu（n,2n）^174mLu, ¹⁷⁵Lu（n,2n）^174gLu and ¹⁷⁵Lu（n,α）¹⁷²Tm reactions on lutetium have been measured at neutron energies from 13.5 to 14.8 MeV using activation technique and by means ofγ-ray spectrometry. The neutron fluences were determined using the monitor reaction ⁹³Nb（n, 2n）^92mNb or ²⁷Al（n,α）²⁴Na and the neutron energies were measured by the mmethod of cross-section ratios for ⁹⁰Zr（n,2n）^89m+gZr to ⁹³Nb（n,2n）^92mNb reactions. The results of the present work are compared and discussed with the values of previous researchers.In the measurement of cross section of nuclear reaction, according to the regulation of growing and decay of artificial radioactive nuclide, a general formula used to subtract the effect of EC orβ^- decay to cross section measured was deduced; a calculation method of cross-section measurement of nuclear reaction with the same product is deduced ; the effects of different monitors in the cross section measurements of nuclear reactions by 14MeV neutrons, at the same time some monitors and correlative parameters were given.The experimental （n,2n）、（n,p）、（n,α）、（n,t） and （n,³He） cross section around 14.S MeV have been collected, analyzed, and evaluated. Data were taken from National Nuclear Data Center （NNDC） up to the end of 2007. Systematics are proposed for the （n,2n）、（n,p）、（n,α）、（n,t）and （n,³He） reactions cross-sections at 14.5 MeV neutron enery based on the statistical model. The systematics provides the bast description of experimental data compared with formulas proposed earlier by other authors.更多还原