摘要
利用 95MeV的19F束轰击116 Sn靶 ,采用 11台反康普顿BGO HPGe探测器对蒸发剩余核退激发射的γ射线进行γ γ符合测量 .通过对多普勒展宽峰的形状分析测定了131Ce和131Pr高自旋态的寿命 .根据寿命数据提取的跃迁四极矩显示 ,在带交叉区发生形状变化 .通过与相邻偶 偶核芯130 Ce的比较表明 ,价中子对核芯形状变化的影响大于价质子的影响 .
The 95 MeV 19F beam projects on an enriched Sn target with backing. The γ-ray emitted from evaporation-residual nuclei were detected in γ-γ coincidence measurement by using 11 BGO Compton suppressed HPGe detectors. Lifetimes of the high spin states for 131Ce and 131Pr were determined through analysis of the Doppler broadened line shapes. The transition quadrupole moments extracted from the measured lifetimes demonstrate that change in nuclear shape occurs in the band crossing region. From a comparison with the neighbouring even-even nucleus 130Ce it follows that influence of the valence neutron is stronger than that of the valence proton on shape change of the core.
出处
《高能物理与核物理》
EI
CSCD
北大核心
2005年第3期240-244,共5页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金 (19975 0 70 )
国家重点基础研究发展规划项目 (G2 0 0 0 0 7740 5 )资助~~
