Nuclear spins and magnetic moments

The main relevant facts concerning nuclei are as follows. 

Interactions arising from nuclear magnetic and electric moments 

State is many orders of magnitude greater than fliat encountered in molecular physics. In fact, the interactions in this state are so weak fliat it is not even bound. 

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The relationship between nuclear spin and magnetic moment leads to a set of observable magnetic i uanuim states lu given by... 

At very high resolutions it may be possible to determine pj from hfs, and from this to calculate /. The hyperfine splitting and shifting of optical lines have yielded important information not only about nuclear spins and magnetic moments, but also about the electric charge distribution and radius of the nucleus. 

Investigations at the interface of atomic and nuclear physics have been fruitful for a considerable time. It is now history how high resolution atomic spectroscopy has contributed to the development of the nuclear shell model through the systematic measurement of nuclear spins and magnetic moments, and also how it pointed out its failures by the observation of large quadrupole moments of nuclei. Had it stopped here, I would not discuss the subject further. In fact, the situation developed quite differently, and much of it has been made possible by important experimental advances, which led to Nobel awards to several of our colleagues at this conference ... 

Ekstrom, L. Robertsson, G. Wannberg, J. Heinemeier, Nuclear Spins and Magnetic Moments of some Neutron-Rich Rubidium and Cesium Isotopes, Physica Scripta 19 516 (1979) H. Gerhardt,... 

The ABMR method has been applied to several different elements at ISOLDE for measurements truunly of nuclear spins and magnetic dipxrle moments. The main results have been obtained in the alkali elements j,Rb (8, 9], 55CS [9-11] and jiFr [12,13], and in Au [14, 15]. Shorter sequences have been studi in jjBr [16], In [17], L 63EU [18,19], Tm [19], and T1 [17]. 

A considerable extension of the ABMR measurements in the alkali elements, discussed above, was obtained by the introduction of the atomic-beam laser experiments at ISOLDE. With this method the nuclear quadrupole moments could be reached by studying the hfs of the excited state, as well as the IS in the isotopic sequences studied. A number of nuclear spins and magnetic dipole moments was also added. Of particular importance was the discovery of the Dj optical line in francium which opened the way to hfs and IS measurements in this element. The atomic-beam laser spectroscopy works at ISOLDE on the alkali elements 3,Rb, 55CS and Fr have been presented in Refs. [20-25]. 

Furthermore, the spin I = S/2,7/2 and 9/2 states discussed here are built up mainly of sublevels from dj/j, Z n and h, j, respectively. One may therefore conclude that the nuclear structure of mesc we y deformed nuclei are described by relatively pure shell-model states, as evidence also by the measured spins and magnetic moments, and that the variations in occupation of the corresponding sublevels with increasing deformation account for the observed changes in the spectroscopic quadrupole moments. 

Rotational effects (fine structure) are also seen in high resolution electronic and vibrational spectra additional structure due to the interaction of electrons with nuclear electric and magnetic moments may also be observed and is called hyperfine structure. The simplest rotational spectra are associated with diatomic molecules with no electronic orbital or spin angular momentum (i.e. singlet sigma states) and these are considered first. 

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