How fission fragments acquire their angular momentum

For $252\mathrm{Cf}(\mathrm{sf})$, $232\mathrm{Th}(\mathrm{n},\mathrm{f})$, $238\mathrm{U}(\mathrm{n},\mathrm{f})$ and $235\mathrm{U}(\mathrm{n}_{\mathrm{th}},\mathrm{f})$, determine when (before scission, at scission, or after, during shape relaxation of the deformed fragments) and through which collective modes (bending, wriggling, twisting, tilting) the fragment spins $J_{\mathrm{L}}$ and $J_{\mathrm{H}}$ of several $\hbar$ are generated. An answer is a dynamical calculation that reproduces the measured mean spins versus fragment mass, the observed lack of correlation between $\mid J_{\mathrm{L}}\mid$ and $\mid J_{\mathrm{H}}\mid$, and their dependence on total kinetic energy.

A microscopic calculation of the joint distribution $P(J_{L}, J_{H})$ that matches gamma-spectroscopy data on spin magnitudes versus fragment mass and total kinetic energy, plus a direct measurement of spin orientation correlations.