Shell structure in deformed nuclei

From a plot of the eigenvalues for the harmonic oscillator without iota.s- or iota2-terms, shell structure is observed for a wide variety of different prolate, oblate and spherical structures in the forms of gaps in the level structure. These gaps occur at a variety of different nucleon 'magic numbers' which vary depending on the deformation. As in the case for spherical nuclei, these 'magic numbers' are subject to small increases due to spin-orbit and other correction terms. Experimental evidence for the special stability caused by this shell structure is presented both for light and heavier nuclei. For the most part this experimental evidence is spectroscopic in nature. Usually it represents the observation of a ground state or low lying band with a value of h2/2J which is anomalously small. A plot of the 2+ energies of these anomalous rotational bands over the entire nuclear periodic table shows that these energies can be correlated with the appropriate shapes and shell structures. Attempts to calculate the corresponding potential energy surfaces using the Strutinsky shell correction method are also described and a brief presentation of an oblate superheavy nucleus (Z equals 124, N equals 176) is given. (author)