New spontaneous fission mode for252Cf: Indication of hyperdeformed144,145,146Ba at scission

From ��-ray coincidence studies following spontaneous fission of 252Cf, direct measurements of yields and neutron multiplicities were made for Sr-Nd, Zr-Ce, Mo-Ba, Ru-Xe, and Pd-Te correlated pairs. A strong enhancement of the 7-10 neutron channels for Mo-Ba pairs is observed. A new fission mode associated with the enhanced neutron yields is identified. These data can be interpreted in terms of one or more of 144,145,146Ba being hyperdeformed at scission. Mean field calculations predict a hyperdeformed third minimum in 252Cf and an extremely deformed 146Ba fragment at scission.