基于形变Woods-Saxon势下的推转壳模型对Se同位素进行Total-Routhian-Surface(TRS)计算。结果表明,原子核的形状随中子数变化很明显。对66,72,92,94Se基态TRS图进行分析,发现缺中子同位素和中子滴线附近核素均存在扁椭球和长椭球的形状共存。分别对72Se和94Se进行推转计算,长椭球和扁椭球形状在低推转频率下共存,由于g9/2闯入轨道的影响,随着推转频率的增加,扁椭球形变逐渐消失,长椭球形变带成为转晕带。
Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface(TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of ^66, 72, 92, 94Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for ^72, 94Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g9/2 orbitals.