Multiphoton Spectroscopy of Small Molecules and Atomic Helium (Physics)

将继续对简单原子和分子进行高分辨率测量的计划，特别集中在双电子系统分子氢和原子氦上。 实验方法涉及基态和亚稳态物质的多光子激发。 脉冲放大连续波染料激光器用于获得多光子激发所需的高功率，同时保持高分辨率。 氢的解离能和电离势将被确定到新的精度，并且将对氦的结构进行改进的测量。 这些测量将为双电子系统基态量子电动力学效应的计算提供首次严格的测试。 微波-光学双共振将用于精确测量高里德伯态之间的跃迁。 这项研究的主要重点是氢中激发态与电离和解离连续体的相互作用，包括双激发态的影响。 里德伯态的衰变将在有和没有外部电场的情况下进行研究。 我们将继续研究非常接近阈值的氢的光解离，从而产生有关原子之间长程相互作用的详细信息。

A program of high resolution measurements on simple atoms and molecules will be continued, concentrating especially on the two-electron systems molecular hydrogen and atomic helium. The experimental methods involve multiphoton excitation of both ground state and metastable species. A pulse-amplified cw dye laser is used to obtain the high powers required for multiphoton excitation while retaining high resolution. The dissociation energy and ionization potential of hydrogen will be determined to a new accuracy, and improved measurements will be made of the structure of helium. These measurements will provide the first stringent tests of calculations of quantum electrodynamic effects in the ground states of two-electron systems. Microwave-optical double resonance will be used to precisely measure transitions between high Rydberg states. A major focus on this research will be the interaction of excited states in hydrogen with the ionization and dissociation continua, including the effects of doubly excited states. The decay of Rydberg states will be studied both with and without external electric fields. Work will continue on the photodissociation of hydrogen very near threshold, which yields detailed information on long-range interactions between atoms.