Acquisition of Improved Laser System for New Experiments in Atomic Physics

9413457 Leventhal本补助金提供的设备包括激光系统，将显着增加波长范围和质量的激光辐射在原子物理实验室在UMSL。 这一升级将使该实验室的设施得到最大限度的利用，并使该实验室最近开发的实验技术得到更充分的利用。 这些实验都依赖于使用多束激光连续激发原子，旨在阐明原子的基本性质。 最近的工作利用了本实验室开发的新的实验技术，以前所未有的精度测量原子参数。 其中两种技术，精密直流斯塔克光谱和Floquet光谱，分别基于直流和交流斯塔克效应。 两者都使用高度激发的原子来放大原子对场的响应。第三种技术，为研究激发原子的光电离而开发，采用各种激光束偏振方案来获取数据，结合角动量代数，使其能够确定光电离到特定最终角动量状态的横截面。 可用激光波长范围的增加将大大扩展实验能力。 新的最先进的设备将使人们有可能研究更广泛的各种原子过程，比目前可能的更详细。 较窄的带宽将允许光谱特征的更精细的分辨率，而较高的可用强度将允许激发目前无法访问的原子跃迁。 与所有实验室资源一样，所要求的系统将为参与本研究的许多本科生提供经验和培训。 此外，中学教师亦可在暑期训练课程中获得宝贵的实验室经验。 因此，这种设备除了作为实验室工具的内在价值外，还将发挥教育作用，培训学生和教师操作最先进的仪器。***

9413457 Leventhal The equipment supplied by this grant consists of laser systems that will significantly increase the wavelength range and the quality of the laser radiation available in the Atomic Physics Laboratory at UMSL. This upgrade will permit maximum utilization of the facilities and fuller exploitation of experimental techniques recently developed in this laboratory. The experiments, all of which rely on sequential excitation of atoms using multiple laser beams, are aimed at elucidating fundamental properties of atoms. Recent work has exploited new experimental techniques developed in this laboratory for measuring atomic parameters with unprecedented accuracy. Two of these techniques, precision dc Stark spectroscopy and Floquet spectroscopy, are based on the dc and ac Stark effects respectively. Both employ highly excited atoms to magnify atomic responses to the fields. A third technique, developed for the study of photoionization of excited atoms, employs a variety of laser beam polarization schemes to acquire data which, in conjunction with angular momentum algebra, make it possible to determine the cross sections for photoionization to specific final angular momentum states. The increased range of available laser wavelengths will greatly expand experimental capabilities. The new state-of-theart device would make it possible to study a wider variety of atomic processes in considerably greater detail than currently possible. The narrower bandwidth would permit finer resolution of spectral features while the higher available intensity would allow excitation of atomic transitions that cannot currently be accessed. As with all laboratory resources, the requested system would provide experience and training for the many undergraduate students who participate in this research. It would also benefit the secondary school teachers who gain valuable laboratory experience during summer training sessions. Thus, this equipment, in addition to its intrins ic value as a laboratory tool, would serve an educational function, training students and teachers in the operation of state-of- the-art instrumentation. ***