O^3＋与H2碰撞中非解离电荷转移过程的全量子计算  

Quantum-mechanical calculations of vibrationally resolvedcross sections for non-dissociative chargetransfer of O^(3+) with H_2

作　　者：吴勇[1] 刘玲[1] 王建国[1,2] 

机构地区：[1]北京应用物理与计算数学研究所计算物理实验室,北京100088 [2]中国科学院近代物理研究所,兰州730000

出　　处：《物理学报》2008年第2期947-956,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10604011,10574018,10574020);国家高技术研究发展计划(863)惯性约束聚变领域资助的课题.~~

摘　　要：应用全量子的分子轨道强耦合方法,研究了基态的O3+(2s22p2P)与氢分子碰撞的非解离电荷转移过程,计算了不同方位角(25°,45°,89°),能量分别为100,500,1000和5000eV/u时的单电子俘获的振动分辨的态选择截面及相应的微分截面.分子轨道强耦合计算中采用了自旋耦合价带理论计算的三原子分子势能面和径向耦合矩阵元.对氢分子的自身转动,采用无限阶的冲量近似方法;对体系的电子运动同H2或H2+的振动之间的耦合,采用了振动冲量近似.结果发现,对不同的入射能量,振动态选择截面随振动量子数的分布发生了一定的改变;不同入射能量和不同方位角的振动态分辨的微分截面具有类似的结构,在极小的散射角附近出现一个最大值平台,然后散射截面随着散射角的增大而减小,并出现大量的震荡结构,其中第一个震荡结构对应的散射角位置随入射能量Ep以Ep-1/2的标度规律变化;微分截面的结构和大小对H2方位角α的变化敏感,这种性质为H2取向的诊断提供了一种可能的途径.Charge transfer due to collisions of ground state O3^＋ （2s^22p^2p） ions with molecular hydrogen is investigated using the quantum-mechanical molecular-orbital close-coupling （MOCC） method, and electronic and vibrational state-selective cross sections along with the corresponding differential cross sections are calculated for projectile energies of 100,500, 1000 and 5000 eV/u at the orientation angles of 25°,45° and 89°. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations were obtained with the spin-coupled valence-bond approach. The infinite order sudden approximation （IOSA） and the vibrational sudden approximation （VSA） are utilized to deal with the rotation of H2 and the coupling between the electron and the vibration of H2 . It is found that the distribution of vibrationally resolved cross sections with the vibrational quantum number v＇ of H2^＋ （v＇） varies with the increment of the projectile energy; and the electronic and vibrational stateselective differential cross sections show similar behaviors： there is a highest platform within a very small scattering angle, beyond which the differential cross sections decrease as the scattering angle increases and lots of oscillating structures appear, where the scattering angle of the first structure decreases as Ep- 1/2 with the increment of the projectile energy Ep ; and the structure and amplitude of the differential cross sections are sensitive to the orientation of molecule H2 , which provides a possibility to identify the orientations of molecule H2 by the vibrational state-selective differential scattering processes.

关 键 词：非解离电荷转移过程 全量子的分子轨道强耦合方法 无限阶冲量近似 振动冲量近似 

分 类 号：O561[理学—原子与分子物理]