Abstract
We find that narrow lines at 1043 and 1062 keV in the summed-energy, 180°-correlated two-photon spectrum from ≊6-MeV/nucleon U+Th collisions can be produced by cascades from high-spin states () in . We see no evidence for narrow two-photon lines in U+Th, Th+Th, and U+U collisions corresponding to the electron-positron lines seen by others: In the summed-energy region between 1.2 and 2.0 MeV, we set an upper limit for the cross section of 6× averaged over a target thickness of 1 mg/.
- Received 15 February 1989
DOI:https://doi.org/10.1103/PhysRevLett.62.2353
©1989 American Physical Society