RUI: Structure and dynamics of cold Rydberg gases and cold plasmas

这项提议是为了继续支持科尔比学院关于寒冷、稠密、里德伯格气体的研究计划。这种环境中的里德堡原子受到偶极相互作用的强烈耦合，这些力可以对原子的运动产生巨大的影响。特别是，已经观察到冷的里德堡原子自发演化成等离子体，这是一个由偶极力启动的过程。里德堡态也是由冷原子光致电离产生的超冷等离子体中的三体电子-离子复合形成的。有理论和实验证据表明，里德堡原子的存在可能对这种等离子体中的电子温度起到控制作用。Rydberg原子之间的偶极作用力可以导致新的分子体系的形成，这可以通过光谱手段来识别。我们构建了一个磁光陷阱(MOT)(密度为1×1010 cm-3，温度为100 UK)。利用脉冲激光选择性地激发冷的里德堡原子。为了实现原子或分子态的高分辨率光谱，我们建立了一个可调谐的毫米波光源。这一来源提供的高分辨率也使人们能够对特定的里德堡态进行标记，并以极高的精度监测这种态的粒子数动态。在不久的将来，将进行三个广泛相关的领域。高n态里德堡寿命的测量，超冷等离子体中的温度控制和里德堡分子的光谱。

This proposal is to continue support for a research program on cold, dense, RydbergGases at Colby College. The Rydberg atoms in this environment are strongly coupled by the dipoleinteraction, and these forces can have a dramatic influence on the atomic motions. Inparticular, cold Rydberg atoms have been observed to spontaneously evolve to plasma, aprocess that is initiated by dipole forces. Rydberg states are also formed by three-bodyelectron-ion recombination in ultra cold plasmas that are created by photoionization ofcold atoms. There is theoretical and experimental evidence that the presence of Rydbergatoms may play a role in control of the electron temperature in such plasmas. Dipole forcesbetween Rydberg atoms can lead to the formation of novel molecular systems, which maybe identified by spectroscopic means.A rubidium magneto-optical trap (MOT) has been constructed (density 1 x 1010 cm-3, temperature 100 uK). Cold Rydberg atoms are selectively excited using a pulsed laser. In order to perform high- resolution spectroscopy of atomic or molecular states, a tunable millimeter wave source has been built. The high resolution available from this source also enables one to "tag" a particular Rydberg state, and monitor the population dynamics of this state with great precision. In the immediate future, three broadly related areas will be pursued. Measurement of Rydberg lifetimes in hiught n states, temperature control in ultra cold plasmas and the spectroscopy of Rydberg molecules .