Coulomb breakup of neutron-rich $^{29,30}$Na isotopes near the island of inversion
A . Rahaman, Ushasi Datta, T. Aumann, S. Beceiro-Novo, K. Boretzky, C. Caesar, B. V. Carlson, W. N. Catford, S. Chakraborty, M. Chartier, D. Cortina-Gil, G. De.… 展开作者
A . Rahaman, Ushasi Datta, T. Aumann, S. Beceiro-Novo, K. Boretzky, C. Caesar, B. V. Carlson, W. N. Catford, S. Chakraborty, M. Chartier, D. Cortina-Gil, G. De. Angelis, D. Gonzalez-Diaz, H. Emling, P. Diaz Fernandez, L. M. Fraile, O. Ershova, H. Geissel, B. Jonson, H. Johansson, N. Kalantar-Nayestanaki, R. Krücken, T. Kröll, J. Kurcewicz, C. Langer, T. Le Bleis, Y. Leifels, G. Münzenberg, J. Marganiec, T. Nilsson, C. Nociforo, A. Najafi, V. Panin, S. Paschalis, R. Plag, R. Reifarth, C. Rigollet, V. Ricciardi, D. Rossi, H. Scheit, H. Simon, C. Scheidenberger, S. Typel, J. Taylor, Y. Togano, V. Volkov, H. Weick, A. Wagner, F. Wamers, M. Weigand, J. S. Winfield, D. Yakorev, M. Zoric
备注：
Modified version of the manuscript is accepted for publication in Journal of Physics G, Jan., 2017
第一个结果报告的基态配置的中子丰富的$^{29,30}$钠同位素，通过库仑解离（CD）测量作为一种方法的直接探测。利用德国达姆施塔特GSI的FRS-ALADIN-LAND装置，在能量为400-430 MeV/核子的$^{208}Pb$靶上，通过库仑激发后所有衰变产物的四动量测量，得到了这些核的不变质量谱。分别提取了激发能为10 MeV的89 $(7)$ mb和167 $(13)$ mb从$^{29}$ Na和$^{30}$ Na中去除一个中子的积分库仑解离截面（CD）。一个中子去除的主要部分，这些原子核的CD截面填充核心，在其基态。与直接碎裂模型的比较表明，$^{29}$ Na ${(3/2^+)}$和$^{30}$ Na ${(2^+)}$基态的价中子主要占据$d$轨道，而与核基态耦合的$s$ -轨道贡献很小.这些核的基态构型分别为$^{28}$ Na、$_{gs (1^+)\otimesν_{s,d}$和$^{29}$ Na $_{gs}(3/2^+)\otimesν_{ s,d}$。从实验中得到的这些核的基态自旋和宇称与以前报道的值一致。首次提取并报道了这些核基态时占据$s$和$d$轨道的价中子的光谱因子。实验结果与壳模型计算使用MCSM的比较表明，在$^{30}$ Na的sd-pf壳隙的下限约为4.3 MeV。
英文摘要：
First results are reported on the ground state configurations of the neutron-rich $^{29,30}$Na isotopes, obtained via Coulomb dissociation (CD) measurements as a method of the direct probe. The invariant mass spectra of those nuclei have been obtained through measurement of the four-momentum of all decay products after Coulomb excitation on a $^{208}Pb$ target at energies of 400-430 MeV/nucleon using FRS-ALADIN-LAND setup at GSI, Darmstadt. Integrated Coulomb-dissociation cross-sections (CD) of 89 $(7)$ mb and 167 $(13)$ mb up to excitation energy of 10 MeV for one neutron removal from $^{29}$Na and $^{30}$Na respectively, have been extracted. The major part of one neutron removal, CD cross-sections of those nuclei populate core, in its' ground state. A comparison with the direct breakup model, suggests the predominant occupation of the valence neutron in the ground state of $^{29}$Na${(3/2^+)}$ and $^{30}$Na${(2^+)}$ is the $d$ orbital with small contribution in the $s$-orbital which are coupled with ground state of the core. The ground state configurations of these nuclei are as $^{28}$Na$_{gs (1^+)\otimesν_{s,d}$ and $^{29}$Na$_{gs}(3/2^+)\otimesν_{ s,d}$, respectively. The ground state spin and parity of these nuclei, obtained from this experiment are in agreement with earlier reported values. The spectroscopic factors for the valence neutron occupying the $s$ and $d$ orbitals for these nuclei in the ground state have been extracted and reported for the first time. A comparison of the experimental findings with the shell model calculation using MCSM suggests a lower limit of around 4.3 MeV of the sd-pf shell gap in $^{30}$Na.
Island of Inversion in neutron-rich cobalt isotopes revealed from mass measurements
Université de Bordeaux, CNRS/IN2P3, LP2I Bordeaux, UMR 5797（波尔多大学）；Université de Strasbourg, CNRS, IPHC UMR 7178（斯特拉斯堡大学）；Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534（诺曼底卡昂大学）；SCK·CEN, Belgian Nuclear Research Centre（比利时核研究中心）；Grand Accélérateur National d’Ions Lourds (GANIL)（重离子国家加速器）；Normandie Univ., UNICAEN（诺曼底大学）；University of Jyväskylä（于韦斯屈莱大学）
Probing the quantum phase transition around $N\approx60$ via mass measurements of technetium isotopes
University of Jyväskylä（于韦斯屈莱大学）；Comenius University in Bratislava（布拉迪斯拉发康斯坦丁神学家大学）；University of Warsaw（华沙大学）；National Centre for Nuclear Research (NCBJ)（国家核研究中心）；University of Brighton（布莱顿大学）；Uppsala University（乌普萨拉大学）；GANIL, CEA/DSM-CNRS/IN2P3（法国国家大尺度加速器联合实验室）；Sofia University "St. Kliment Ohridski"（索非亚大学）
Future of superheavy element research: Which nuclei could be synthesized within the next few years?
Z $>$ 120的核的熔合截面的低值和非常短的半衰期给新元素的合成带来了障碍。本文讨论了可用于生产超重元素新同位素的各种核反应（稳定核和放射性核的聚变、多核子转移和中子俘获）。位于冷聚变反应和热聚变反应早期产生的同位素之间的未知SH核的间隙可以在$^{48}$ Ca与可用的较轻同位素Pu、Am和Cm的聚变反应中填充。这些核的产生的截面预计是相当大的，相应的实验可以很容易地在现有的设施进行。对于第一次，一个狭窄的途径被发现的稳定岛的中间，由于可能的$β^+$ -衰变的SH同位素，可以形成在普通的聚变反应的稳定核。多核子转移过程中的重（和非常重，U-类）离子的近势垒碰撞被证明是相当现实的反应机制，使我们能够产生新的中子富集的重核位于未开发的上部的核地图。中子俘获反应也可用于产生长寿命富中子SH核。脉冲核反应堆和实验室条件下的核爆炸以及自然界中的超新星爆炸都可能提供强中子通量。所有这些可能性的文件中进行了讨论。
