Spectroscopy of Rydberg States

The spectroscopy of Rydberg states with large principal quantum numbers n has recently gained increasing interest [8.78a]. This subject is a good example 

R = Rydberg constant, ag = Bohrradius, n = principal quantum number. 

A possible experimental setup is shown in Fig.8.14b, where the laser beams cross the atomic beam inside a parallel plate capacitor, providing a homogeneous electric field. Electrons escaping through the mesh in the capacitor plate 

The study of Rydberg spectra and ionization thresholds of ten lanthanides and actinides has been reported by PAISNER et al. [8.80]. In these experiments, high-lying states were accessed by time-resolved stepwise excitation using pulsed dye lasers tuned to resonant transitions. Atoms excited to levels within 1000 cm of the ionization limit were then photoionized by 10.6 ym radiation from a pulsed CO2 laser. The measurements allowed the accurate determination of ionization thresholds from Rydberg convergences to within 0.0005 eV. 

The advantages of infrared laser Stark spectroscopy (Sect.8.3.2) in combination with optical excitation have been utilized by DUCAS et al. [8.81]. 

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Why microwave resonance techniques are so attractive for the spectroscopy of Rydberg states becomes clear when we estimate how much microwave power is required to drive the transitions. To drive the electric dipole ml— ni transition A... 

The Stark splitting and the field ionization of very high Rydberg levels provide sensitive indicators for measuring weak electric fields. These few examples demonstrate the variety of information obtained from Rydberg state spectroscopy. More examples can be found in Sect. 9.5 and in the literature on laser spectroscopy of Rydberg states [593-597]. 

We hope that high-resolution laser spectroscopy of Rydberg states of two-electron systems, which has developed rapidly within the last three years and has contributed considerably to our knowledge of the electronic structure of such states, will continue to serve this purpose. 

W. Hogervorst Laser spectroscopy of Rydberg states of two-electron atoms. Comments At. Mol. Phys. 13, 69 (1983)... 

Sandorfy C (ed) 1999 The Role of Rydberg States in Spectroscopy and Photochemistry (London Kluwer Academic)... 

T. P. Softley The aims of ZEKE spectroscopy are conceptually different from the atomic pulsed-field ionization experiments that predate ZEKE. In the latter, the aim is always to observe and study the individual Rydberg states. In ZEKE spectroscopy the aim is to detect small batches of Rydberg states lying below successive vibration-rotation thresholds of the ion without specific interest in the individual Ryd-... 

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