GAMMA-DECAYS OF HIGH-SPIN ISOMERS IN THE VICINITY OF CLOSED SHELLS ASA KEY FOR STUDYING ORDER-TO-CHAOS TRANSITIONS IN NUCLEI

Based on the statement that there is order in the large and chaos in t he small components of nuclear wave functions, the order-to-chaos tran sition is treated as a transition from the large to the small componen ts of the wave functions. Therefore, experimental investigation of the fragmentation of many-quasiparticle and quasiparticle x phonon states plays a decisive role. High spin isomers in the vicinity of closed sh ells demonstrate the regularities of the nuclear mean field. Gamma-ray s de-exciting the levels above the yrast line, including weak transiti on rates, give information on the fragmentation of many-quasiparticle x phonon states which can be used for studying order-to-chaos transiti ons. Resemblance and distinction between nuclei in the vicinity of clo sed shells and well-deformed nuclear are discussed.