Fast Beam Studies of Excited States of Atoms and Molecules (Physics)

利用快束技术可以在相对没有碰撞和其他微扰的环境中研究原子和分子的激发态。这项建议中的工作利用了一种非常灵敏的方法来检测这种状态，使用共振激光激发到非常弱的束缚状态，然后进行斯塔克电离。与此相结合的是非常高分辨率的微波光谱技术。为了验证相对论原子理论的预言，提出了用实验来仔细研究氦的高角动量里德堡态的精细结构。为了获得关于H2+离子的精确的新信息，还将研究H2分子的类似里德伯格态。另一个应用将是精确测量原子氢中n=4的精细结构，这可能导致新的精细结构常数α的测定。

Excited states of atoms and molecules may be studied in an environment relatively free of collisions and other perturbations by the use of fast beam techniques. The work in this proposal makes use of a very sensitive method of detecting such states using resonant laser excitation to a very weakly bound state followed by Stark ionization. Combined with this are very high resolution techniques of microwave spectroscopy. Experiments are proposed to carefully study the fine structure of high angular momentum Rydberg states of helium in order to test predictions of relativistic atomic theory. Similar Rydberg states of the H2 molecule will also be studied in order to yield precise new information about the H2+ ion. Another application will be a precise measurement of n=4 fine structure in atomic hydrogen which may lead to a new determination of the fine structure constant alpha.