超重新核素合成研究进展

Synthesis of new superheavy nuclei

随着重离子加速器和放射性核束装置的发展,人们对于核物理的研究不再仅仅局限于稳定核,更是将研究对象扩展到一些极限条件,比如探索原子核高温高密极限、自旋极限、同位旋极限,以及电荷和质量极限等.对于探索电荷和质量极限而言,如何合成长寿命超重核、是否存在“超重稳定岛”以及如何研究超重原子核的性质,成为当前核物理学研究的前沿领域.本文回顾了超重核的产生机制、定义和衰变模式,详细介绍了国内外关于超重核合成的现状和研究进展.其中包括理论上和实验上合成超重核素最新研究进展,重点针对重离子熔合反应和多核子转移反应研究情况展开讨论,并简介了国际上核科学大装置未来开展超重核研究的计划.同时,对北京师范大学参与93号超铀新核素^(223,224)Np的合成情况进行了评述,并针对近年来合成Z=119和120超重核素的最新研究进行了总结展望.

With heavy ion accelerators and radioactive ion beam facilities readily available,nuclear physics is no longer limited to stable nuclei, but extends rather to some limiting conditions such as high-temperature and highdensity limits,spin limit,isospin limit,charge and mass limits. To explore charge and mass limits,the following are at the forefront of nuclear physics research: how to synthesize long-lived superheavy nuclei, whether an “island of stability” exists,how to study the properties of superheavy nuclei. In this paper,mechanisms,definitions and decay modes of superheavy nuclei are reviewed. Synthesis of superheavy nuclei are reviewed, including theory and experimental synthesis of superheavy nuclei,future plans for large-scale facilities. The study of synthesis mechanism of superheavy nuclei is carried out in heavy-ion fusion reactions and multinucleon transfer reactions. Synthesis of new trans-uranium nuclei ^(223,224)Np and participation of Beijing Normal University personnel are reviewed. Recent progresses in the synthesis of Z=119 and 120 superheavy nuclei are summarized.