Fission Fragment Orientation and γ-RAY Emission Anisotropy

Angular correlations of prompt γ-rays in binary spontaneous fission of ²⁵²Cf were measured with a GSI super clover detector. The position-sensitive γ-ray spectrometer was combined with an efficient detection system for fission fragments. For the study of γ-ray angular correlations the intensities of individual γ-transitions were measured relative to the fission axis. Surprisingly, the measured γ-ray angular correlations for stretched E2 transitions show a large anisotropy, which can be described by a complete alignment of the initial fragment spins.