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

原子和分子的激发态可以用快束技术在相对没有碰撞和其他扰动的环境中研究。本提案中的工作利用了一种非常灵敏的方法来探测这种状态，使用谐振激光激发到一个非常弱的束缚态，然后是斯塔克电离。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测，提出了实验来仔细研究氦的高角动量里德伯态的精细结构。H2分子类似的里德伯态也将被研究，以获得关于H2+离子的精确的新信息。另一个应用将是对原子氢n=4精细结构的精确测量，这可能导致精细结构常数α的新测定。

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.