【作者】 陈建勇；

【导师】 王铁山；

【作者基本信息】 兰州大学 ， 原子与分子物理， 2008， 硕士

【摘要】 在天体物理感兴趣的远低于库仑势垒的能区,带电粒子的反应截面随能量降低而近似指数的急剧下降,这就使得在这一能区带电粒子核反应截面极难测量。通过实验研究发现,超低能区的氘氘聚变反应的反应截面随反应环境(各种载体金属材料)的改变有非常明显的不同,这主要是由于在金属载体材料中受到屏蔽效应影响而引起的。为了研究载氘金属材料对超低能区的氘氘聚变反应的屏蔽效应,我们在日本东北大学核科学实验室的低能强流加速器上对不同金属材料中的氘氘聚变反应进行了系统测量。本文工作主要是研究在银,铍,铑,锆,钐,镝等载氘金属材料中10到20 keV(实验室系能量)能区的氘氘聚变反应。我们得到了以上六种金属的屏蔽势能依次分别是146±18 eV,163±25 eV 313±48 eV,711±110eV 520±56 eV,395±35 eV,同时根据探测到的D-D反应产生的质子产额推导出了在该能区载体金属材料环境中的相对质子产额。同时,我们还结合国际原子能机构公布的氘氘聚变反应截面的编评数据,得出氘氘聚变反应在以上金属中的激发函数。通过这一激发函数与氘氘聚变反应在气体靶中激发函数的比较,我们发现在金属环境中氘氘聚变反应的反应截面相对于在气体靶中有明显的增大。更多还原

【Abstract】 As the cross section of charged particles drops nearly exponentially at energy far below the Coulomb barrier which is interested in astrophysics,it becomes difficult to measure the cross section with decreasing.It is found in experiments that the cross section of D(d,p)T fusion reactions at sup-low energy is significantly changed in various environments,which is induced by screening effect of the material.In order to investigate the screening effect of deuterium loading metal materials,D(d,p)T fusion reactions in various metal materials were measured systemically using a low-energy ion beam generator at the Laboratory of Nuclear Science of Tohoku University. D(d,p)T fusion reactions in deuterium loading Ag,Be,Rh,Zr,Sm,Dy metals are studied in this work.The screening potentials of the metals mentioned above are 146±18 eV(Ag),163±25 eV (Be),313±48 eV(Rh),711±110 eV(Zr),520±56 eV(Sm),395±35 eV(Dy)respectively. Moreover,The relative proton yields in metals are induced from the yields of protons emitted from the D(d,p)T reactions for bombarding energies between 10～20 keV.Considering the appraised value of cross section of D(d,p)T reactions obtained from International Atomic Energy Agency, the excitation function of D(d,p)T reactions in low energy region in the mentioned metals can be deduced from the relative proton yields.An strongly enhancement of reaction cross section has been derived in comparision with the excitation function with that of the gas target.更多还原