Multiphoton Spectroscopy of Small Molecules and Atomic Helium (Physics)

对简单原子和分子的高分辨率测量计划将继续进行，特别是集中在双电子系统的氢分子和氦原子。实验方法涉及基态和亚稳种的多光子激发。采用脉冲放大的连续波染料激光器，在保持高分辨率的同时获得多光子激发所需的高功率。氢的解离能和电离势的测定将达到新的精度，对氦的结构的测量也将得到改进。这些测量将为双电子系统基态中量子电动力学效应的计算提供第一次严格的测试。微波光学双共振将用于精确测量高里德伯态之间的跃迁。本研究的重点将是氢的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。我们将研究有外加电场和没有外加电场时里德伯态的衰变。研究氢在非常接近阈值时的光解作用的工作将继续进行，这将产生原子间远距离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.