共振相干激发的最新实验研究(英文)

Recent Experiments on Resonant Coherent Excitation of Heavy Ions at HIMAC

在满足沟道效应条件下 ,高能离子在穿过晶体时 ,离子穿过的是周期性的原子序列或者有序平面阵列 .在入射离子的坐标系中 ,离子感受到一种振动场的作用 .如果与此振动频率相关的能量与离子的电子态跃迁能量相匹配 ,则离子有可能被激发 ,这种现象就称为共振相干激发 (RCE) .1998年 ,成功地观测到了类氢Ar17+ 离子以相对论速度穿过Si晶体时 ,其 1s电子到n =2态的共振激发 .此后 ,有关出射离子电荷态分布以及退激X射线谱的实验研究取得了很大进展 ,近期的实验研究还观测到了类氢离子的 1s电子到更高电子态 (n =3,4 ,5 )的RCE和更重离子的RCE ,以及类氦离子的RCE .这些实验结果有助于详细研究这种共振现象 .实验结果表明 ,RCE也能够作为研究高精度原子谱学的一种潜在的工具 .

When energetic ions penetrate into a crystal in a channeling condition, they travel across a periodic array of the atomic strings or ordered planes. These ions feel an oscillating field in the projectile frame. If the energy corresponding to this frequency matches with the transition energy of the electronic states of the ions, the ions have a chance to be excited. It is called Resonant Coherent Excitation (RCE). We have succeeded in observing resonant excitation of 1s electron to the n=2 states in H-like Ar 17+ with relativistic velocities in 1998. Since then, much progress has been made. The observation of the RCE to the higher electronic states, RCE of heavier ions, and RCE of He-like ions in our lab allowed us to understand the resonance phenomena in detail. We also recognized its potentiality as a tool for high-precision atomic spectroscopy.