Shape isomers and cluster structure

A cluster-configuration is defined most easily by a reaction channel [1]. Therefore, the investigation of the possible clusterizations of the shape isomer states gives information not only on the structure, but also on the reaction channels in which they can be populated, or decay. Recently we have carried out this kind of studies for some super- and hyper deformed states systematically [2-4]. An interesting example is provided by the 36Ar nucleus. We have investigated all the possible binary clusterizations [2] (and many ternary ones [3]) by applying selection rules based on the microscopic structure, and simple energy-calculations. From the latter point of view the alpha-like configurations turned out to be favoured, while the structural study gave non-trivial mass-dependence for the allowed clusterization, which was very different in the ground, super deformed and hyper deformed state. For the hyper deformed state the 24Mg+12C and 20Ne+16O configurations turned out to be the preferred ones. A recent analysis [5,6] of 24Mg+12C elastic scattering data [7] gave resonant states of low spin. Together with previous 20Ne+16O resonances [8,9] they determine a deformed band, which seems to be the hyper deformed one. Thus 36Ar is one of the few nuclei, in which in addition to the ground and superdeformed band [10] we may have observed the hyper deformed one, too. Furthermore, its population is completely in line with the prediction of the cluster models [11,2]. In the present contribution we plan to discuss some methodological aspects of these investigations, as well as further examples.(author)