Nörtershäuser W, Tiedemann D, Záková M, Andjelkovic Z, Blaum K, Bissell M L, Cazan R, Drake G W F, Geppert Ch, Kowalska M, Krämer J, Krieger A, Neugart R, Sánchez R, Schmidt-Kaler F, Yan Z-C, Yordanov D T, Zimmermann C
GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany.
Phys Rev Lett. 2009 Feb 13;102(6):062503. doi: 10.1103/PhysRevLett.102.062503.
Nuclear charge radii of ;{7,9,10,11}Be have been determined by high-precision laser spectroscopy. On-line measurements were performed with collinear laser spectroscopy in the 2s_{1/2}-->2p_{1/2} transition on a beam of Be+ ions. Collinear and anticollinear laser beams were used simultaneously, and the absolute frequency determination using a frequency comb yielded an accuracy in the isotope-shift measurements of about 1 MHz. Combining this with accurate calculations of the mass-dependent isotope shifts yields nuclear charge radii. The charge radius decreases from 7Be to 10Be and then increases for the halo nucleus 11Be. When comparing our results with predictions of ab initio nuclear-structure calculations we find good agreement. Additionally, the nuclear magnetic moment of 7Be was determined to be -1.3995(5)micro_{N} and that of 11Be was confirmed with an accuracy similar to previous beta-NMR measurements.
通过高精度激光光谱法测定了(^{7,9,10,11}Be)的核电荷半径。利用共线激光光谱法对一束(Be^+)离子的(2s_{1/2}\to2p_{1/2})跃迁进行了在线测量。同时使用了共线和反共线激光束，通过频率梳进行绝对频率测定，在同位素位移测量中获得了约(1 MHz)的精度。将此与质量相关同位素位移的精确计算相结合，得出核电荷半径。电荷半径从(^{7}Be)减小到(^{10}Be)，然后对于晕核(^{11}Be)又增大。当将我们的结果与从头算核结构计算的预测进行比较时，我们发现吻合得很好。此外，确定(^{7}Be)的核磁矩为(-1.3995(5))核磁子，(^{11}Be)的核磁矩得到了确认，其精度与先前的β核磁共振测量相似。
