Nonadiabatic Effects in Alkali Atom-Rare Gas Interactions: Optical Collisions and Spectroscopy (Physics)

在许多弹性和非弹性碰撞过程中，原子或分子对撞状态之间的非绝热耦合对于确定状态特定截面具有重要作用。这些包括非辐射电子跃迁，如淬火或精细结构跃迁，相干转移和碰撞退极化，以及旋转和振动能量转移。非绝热效应在光分裂过程中也很重要，如光解离、光电离或光的碰撞再分配。实验研究了非绝热耦合对碱（钠和锂）与稀有气体原子光学碰撞动力学的影响。将研究精细结构分支和塞曼多极子的产生，以及最近观察到的精细结构分支对激光强度的非线性依赖。研究LiHe和NaHe分子的Rydberg谱，它们应该通过核心旋转和振动表现出显著的旋转非绝热性。

Nonadiabatic couplings among states of a colliding pair of atoms or molecules have an essential role in determining state- specific cross-sections for a wide range of elastic and inelastic collision processes. These include nonradiative electronic transitions such as quenching or fine-structure transitions, coherence transfer and collisional depolarization, and rotational and vibrational energy transfer. Nonadiabatic effects are also important in photofragmentation processes such as photodissociation, photoionization, or collisional redistribution of light. Experimental studies of effects of nonadiabatic couplings on the dynamics of optical collisions between alkali (sodium and lithium) and rare gas atoms will be carried out. Both fine-structure branching and the production of Zeeman multipoles will be investigated, along with the recently observed nonlinear laser intensity dependence of the fine-structure branching. An investigation of the LiHe and NaHe molecular Rydberg spectrum, which should exhibit significant rotational nonadiabaticity through the core rotation and vibration, will also be pursued.