Guest J R, Scielzo N D, Ahmad I, Bailey K, Greene J P, Holt R J, Lu Z-T, O'Connor T P, Potterveld D H
Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Phys Rev Lett. 2007 Mar 2;98(9):093001. doi: 10.1103/PhysRevLett.98.093001. Epub 2007 Feb 27.
We have demonstrated Zeeman slowing and capture of neutral 225Ra and 226Ra atoms in a magneto-optical trap. The intercombination transition 1S0-->3P1 is the only quasicycling transition in radium and was used for laser-cooling and trapping. Repumping along the 3D1-->1P1 transition extended the lifetime of the trap from milliseconds to seconds. Room-temperature blackbody radiation was demonstrated to provide repumping from the metastable 3P0 level. We measured the isotope shift and hyperfine splittings on the 3D1-->1P1 transition with the laser-cooled atoms, and set a limit on the lifetime of the 3D1 level based on the measured blackbody repumping rate. Laser-cooled and trapped radium is an attractive system for studying fundamental symmetries.
我们已经证明了在磁光阱中实现了对中性225Ra和226Ra原子的塞曼减速和捕获。1S0-->3P1的禁戒跃迁是镭中唯一的准循环跃迁，被用于激光冷却和捕获。沿着3D1-->1P1跃迁进行再抽运，将阱的寿命从毫秒延长到了秒。实验证明，室温黑体辐射可从亚稳态3P0能级提供再抽运。我们用激光冷却的原子测量了3D1-->1P1跃迁上的同位素位移和超精细分裂，并根据测量的黑体再抽运速率确定了3D1能级的寿命上限。激光冷却和捕获的镭是研究基本对称性的一个有吸引力的系统。
