Rydberg hyperfine structure

The change in the reduced mass for this atomic system leads to an energy level structure similar to that of hydrogen but characterised by a Rydberg constant of half the magnitude. Of course, there are other differences as well, for example there is no real distinction any more between fine structure and hyperfine structure. Furthermore the... 

Spectroscopy on the hydrogen molecular ion is difficult. Early results came from photoelectron (14), photoionization (15) and Rydberg spectra (16). Dehmelt and Jefferts (17) succeeded in measuring the radiofrequency spectra of H+ and characterizing the hyperfine structure in the vibrational levels v=4-8. 

Doppler-free two-photon transitions to atomic Rydberg levels [251] allow the accurate determination of quantum defects and of level shifts in external fields. Hyperfine structures in Rydberg states of two-electron atoms, such as calcium and singlet-triplet mixing of the valence state 45 and and Rydberg levels have been thoroughly studied by Doppler-free two-photon spectroscopy [252]. 

With the accuracy of the energy matrices assured, further advances in the analysis of complex lanthanide spectra could be carried out. The histories of the individual ions, complete up to a specified date (usually in 1976 or 1977), have been given by Martin et al. (1978). After 1978, many fits to lanthanide levels were carried out as a preliminary to other projects, such as the analysis of hyperfine structures or Rydberg series. This work is discussed in sections 8.4 and 8.5. Among articles in the classic vein that have not yet been mentioned are that of Wyart et al. (1976/7) on 4f and 4f °(5d-I-6s-I-6p) of Ho III, and that of Kaufman and Sugar (1978) on LuV 4f (5d -I- 6s -I- 6p). The Ndll analyses carried out by Blaise et al. (1984), which have been signposted in section 1, are other examples of that kind. 

In this chapter we concentrate on one particular aspect of Rydberg atom spectroscopy the measurement, analysis, and interpretation of hyperfine structures of Rydberg states of two-electron systems. Although hyperfine interactions have traditionally been used to probe the electronic structure of atomic ground states and low-lying excited levels, isotope... 

Figure 1. Experimental setup for hyperfine structure and isotope shift measurements of Ba Rydberg states. (Taken from Ref. 28.)...

In this section we review isotope shift and hyperfine structure measurements concerning the even-parity Rydberg series msns and msnd 0 of Ca, Sr, and Ba, which have been studied most extensively up to now. Hyperfine interactions occurring in msns S Rydberg states can be readily understood and will be considered first. 

Spin-Orbit Coupling and Hyperfine Structure of Pure msnd Rydberg States... 

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