Hyperfine structure measurements

Markus, R. Hyperfine Structur Measurements on Some Transuranic Elements. 

Hyperfine structure measurements of 75 strong lines at 4020—6200 mm were made by means of interferometer spectrograms. Doublet structures occurred in 30 lines with separations of 0.034—0.180 cm-1 (76). Nuclear spins for 239Pu and for 241Pu have been established to be 1 = 1/2 and 1 = 5/2, respectively. The spins were based on paramagnetic resonance measurements on a RbPu02(N03)3 crystal (77). 

Hyperfine structure measurements using on-line atomic-beam techniques are of great importance in the systematic study of spins and moments of nuclei far from beta-stability. We will discuss the atomic-beam magnetic resonance (ABMR) method, and laser spectroscopy methods based on crossed-beam geometry with a collimated thermal atomic-beam and collinear geometry with a fast atomic-beam. Selected results from the extensive measurements at the ISOLDE facility at CERN will be presented. 

Hyperfine Structure Measurements of Antiprotonic Helium and Antihydrogen... 

Here, I will concentrate on the different on-line atomic-beam techniques used in hyperfine structure measurements at ISOLDE, and on selected experimental results showing the importance of systematic spin and moment measurements. 

W. Ertmer, B. Hofer, Zeiofield hyperfine structure measurements of the metastable states 3d 4s F3/29/2 of SC using laser-fluorescence-atomic beam magnetic resonance technique. Z. Phys. A 276,9 (1976)... 

The first term results from the Fermi contact interaction, while the second represents the long-range dipole-dipole interaction. In the equations above, ge is the free-electron g factor, /Xe the Bohr magneton, gi the nuclear gyromagnetic ratio, and /xi the nuclear moment. Moreover, the nucleus is located at position R, and the vector r has the nuclear position as its origin. Finally, p (r) = p (r) — p (r) is the electron spin density. The only nontrivial input into these equations is precisely this last quantity, i.e. Ps(r), which can be computed in the LSDA or another DFT approximation. The resulting Hamiltonian can be used to interpret the hyperfine structure measured in experiments. A recent application to metal clusters is reported in Ref. [118]. 

W. Ertmer, B. Hofer Zerofield hyperfine structure measurements of the... 

Rosner and collaborators applied the laser-microwave scheme discussed above not only to atoms but for the first time also to ions, particularly to hyperfine structure measurements of Xe. In this work the ion beam passed a coaxial waveguide where the rf transitions were induced. Since the ions moved in opposite direction but parallel to the rf wave propagation, the resonance frequencies had to be corrected for the Doppler shift. 

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. 

Although we have been interested primarily in the investigation of Rydberg series of alkaline-earth elements by hyperfine structure measurements, in this section we briefly comment on similar studies performed on He and Yb. 

R. Gupta, W. Happer, L. Lam, S. Svanberg Hyperfine structure measurements of excited S states of the stable isotopes of potassium, rubidium and cesium by cascade radio-frequency spectroscopy. Phys. Rev. A8, 2792 (1973)... 

S. Svanberg Perturbations in Rydberg sequences probed by lifetime, Zeeman-effect and hyperfine structure measurements, in [Ref.9.23, p. 301]... 

Discuss hyperfine structure and isotopic shifts. What are the origins of these effects What can be learned from these phenomena Certain experimental teclmiques can be used for measuring hyperfine structures as well as isotopic shifts, while others are only useful for hyperfine-structure measurements. How does this arise ... 

J. Farley, P. Tsekeris, R. Gupta "Hyperfine-structure measurements in the Rydberg S and P-states of rubidium and cesium. Phys. Rev. A15, 1530 (1977)... 

This appeared to be the final solution to the problem of the hydrogen atom. However, it should be remembered that a few experimentalists were not entirely happy and questioned whether the Dirac theory of the fine structure was completely correct. There was therefore a need to develop new experimental techniques which would increase the accuracy of fine and hyperfine-structure measurements. 

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