E2 and E4 Transition Moments and Equilibrium Deformations in the Actinide Nuclei
E2 and E4 Transition Moments and Equilibrium Deformations in the Actinide Nuclei
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DOI：
10.1103/physrevc.8.1466
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发表时间：
1973-10
影响因子：
3.1
通讯作者：
C. Bemis;F. McGowan;J. Ford;W. T. Milner;P. Stelson;R. L. Robinson
中科院分区：
文献类型：
--
作者：
C. Bemis;F. McGowan;J. Ford;W. T. Milner;P. Stelson;R. L. Robinson
利用配有位置灵敏比例探测器的分裂极磁谱仪，通过观察弹性和非弹性散射的射弹，在鳗系元素区(230美元)进行了高精度的离子库仑激发实验。研究了从Th到Cm的12个偶数-A元靶，从实验激发几率确定了约化四极矩阵元$〈2\ensuremath{\parallel}\mathfrak{M}(E2)\ensuremath{\parallel}0〉$，和约化十六极矩阵元$〈4\ensuremath{\parallel}\mathfrak{M}(E4)\ensuremath{\parallel}0〉$，。基态转动带中的${4}^{+}$态。$B(E4，0\Ensureath{\right tarrow}4)$的值范围从$^{234}\mathm{U}$的167个单粒子单位到$^{244,246,248}\mathrm{cm}$的基本上为零的单粒子单位。由形变费米分布和形变均匀分布所表示的核电荷分布的测量$E2$和$E4$转变矩，提取了与模型有关的形变参数${\susureath{\beta}}_{20}$和${\susureath{\beta}}_{40}$。
Precision Coulomb-excitation experiments using $^{4}\mathrm{He}$ ions have been performed in the actinide region ($230\ensuremath{\le}A\ensuremath{\le}248$) by the observation of elastic and inelastically scattered projectiles using a split-pole magnetic spectrometer equipped with a position-sensitive proportional detector. 12 even-$A$ targets from $^{230}\mathrm{Th}$ to $^{248}\mathrm{Cm}$ have been investigated and the reduced quadrupole matrix element, $〈2\ensuremath{\parallel}\mathfrak{M}(E2)\ensuremath{\parallel}0〉$, and the reduced hexadecapole matrix element, $〈4\ensuremath{\parallel}\mathfrak{M}(E4)\ensuremath{\parallel}0〉$, have been determined from the experimental excitation probabilities of the ${0}^{+}$, ${2}^{+}$, and ${4}^{+}$ states in the ground-state rotational bands. The values of $B(E4,0\ensuremath{\rightarrow}4)$ range from 167 single-particle units for $^{234}\mathrm{U}$ to essentially zero single-particle units for $^{244,246,248}\mathrm{Cm}$. Model-dependent deformation parameters, ${\ensuremath{\beta}}_{20}$ and ${\ensuremath{\beta}}_{40}$, are extracted from the measured $E2$ and $E4$ transition moments for distributions of nuclear charge represented by deformed Fermi distributions and by a deformed homogeneous distribution.