The Scaled-energy Spectra Of Barium Atoms In External Fields

The correspondence between quantum mechanics and classicalmechanics has been one of the most active research fields in physics. Rydbergatoms play an important role in this field because of their extraordinaryproperties. Recently, technology development allows us to do some researchmore deeply on Rydberg atoms in the external fields, a perfect realexperimental system to study the correspondence. But until now, the effect ofelectron-correlation on the dynamics of many-electron atomic system is stillunclear. Considering that Barium atoms have big cores and some perturbeddoubly excited states, we choose high Rydberg Barium atoms to study. Thisthesis summaries three aspects of my research effort:Firstly, the closed-orbit theory,experimental method of scaled-energyspectroscopy and development in this field are introduced in detail. Themethod of realizing closed-orbit theory is studied. The theoretical recurrencespectra of Hydrogen is obtained using C language and Mathematic software.Secondly, the scaled-energy spectrum of M=0 Rydberg Barium atε=-3.00 in external electric field is recorded experimentally for the first time.The recurrence spectrum coming from the Fourier transform of theexperiment result is compared with the theoretical recurrence spectrum ofHydogen. The violent reduction of the strength of the peaks at largerscaled-action is found. It is possible that this phenomenon comes from theinfluence of perturbed double-excited states.Thirdly, a new apparatus is designed and established, from which theatom spectra in combined electric and magnetic fields can be studied. Thesignal of Rydberg Barium atom was recorded in this apparatus for the firsttime. The absorption spectrum of single photon excitation, stark spectra ofBarium atom and spectra of Barium atom in low magnetic field were obtainedfor the first time in this apparatus.Future research suggestion are proposed forthis setup.