^(178)Hf长寿命同核异能态触发γ跃迁的理论探讨  

Theoretical investigation on the triggered gamma-ray emission from long-lived isomer in ^(178)Hf

作　　者：王飞鹏[1] 沈水法[1,2] 阎玉鹏 

机构地区：[1]中国科学院核能安全技术研究所,合肥230031 [2]苏拉娜里理工大学物理学院,那空叻差是玛泰国30000

出　　处：《核技术》2014年第8期53-57,共5页Nuclear Techniques

基　　金：国家自然科学基金重大研究计划重点支持项目(No.91026004);江西省教育厅科技计划项目(No.GJJ12372)资助

摘　　要：近年来178Hfm2 31年的同核异能态被认为是用低能X射线触发使其释放储存能量的最合适候选者。为了探讨在178Hf中是否存在触发Kπ=16+同核异能态γ发射的门态,本工作首先用投影壳模型对178Hf的多准粒子态和集体激发态进行了研究,结果表明其它态位于距离16+同核异能态较远的地方。但当用包括γ自由度的组态限制(绝热阻塞)方法计算178Hf的多准粒子激发态时,结果显示有三个能级可能是16+同核异能态光退激的候选者,位能面计算的结果显示178Hf为轴对称硬核。Background： ^178Hf^m2 isomer is considered the most suitable candidate to study the depletion of its stored energy induced by low-energy X-ray in recent decades. Purpose： The aim is to research whether there exist potential gateway states which may trigger gamma-ray emission from the K^π=16^＋isomer with low-energy photons. Methods： The projected shell model is at first used to study the multi-quasiparticle and collective excitation states of ^178Hf. Results： The results show that the 16^＋ isomer lies well separated in energy from other states. But when the configuration-constrained （diabatic blocking） calculations, with inclusion of y-deformation, are performed to study the multi-quasiparticle excitation states of ^178Hf, it appears that three levels can be the most likely candidates for photodeexcitation of the 16^＋ isomer. Conclusion： The Potential Energy Surface （PES） calculations in the present work suggest that this nucleus is rigid to axially asymmetric shapes.

关 键 词：触发γ发射 多准粒子激发态 位能面(Potential Energy Surface PES) 

分 类 号：TL11[核科学技术—核能科学]