Development of apparatus for single isotope analysis with lasers

激光烧蚀产生的钙离子被线性Paul陷阱捕获，并被397 nm和866 nm激光冷却，分别对应于4^2S_1/2到4^2P_1/2和4^2P_1/2到3^2D_3/2跃迁。利用额外的850 nm激光进行了量子跳跃实验，观察到了单个钙离子。这项实验显示了计算捕获的钙离子数量的能力。观察到俘获离子寿命与真空度和与背景气体碰撞的关系。研究了捕获的同位素离子与施加在电极上的Rf和DO电压之间的关系。操作电压使人们能够拾取用激光冷却技术光学观察到的单个同位素，这种线性Paul陷阱的质量分离能力与同位素选择性激光冷却技术相结合，使人们能够分析超痕量同位素。

Ca ions generated by laser ablation are trapped by a linear Paul trap and laser-cooled with 397 and 866 nm lasers which correspond to the transitions of 4 ^2S_1/2 to 4 ^2P_1/2 and 4 ^2P_1/2 to 3 ^2D_3/2, respectively. Quantum jump experiment using an additional 850 nm laser was performed to observe single Ca ions. This experiment showed the capability to count the number of trapped Ca ions. Dependence of trapped ion life time on vacuum pressure and collision with background gas was observed. Trapped isotope ions were investigated as a function of rf and do voltages applied to the electrodes. Operating the voltages enables one to pick up single isotopes, which were optically observed with laser cooling technique.This mass separation capability by linear Paul traps combined with isotope-selective laser cooling technique can give one the possibility to analyze ultra trace isotope.