Lattice location of fission products in UO(2) single crystals
Heavy fission product ions (Te, Xe, Cs) were implanted in UO(2) single crystals at 50 keV to high fluences between 5 and 100 x 1.0 E15 ions/cm2. The implantations were performed at 77 K (for Te, Xe) and 293 K (for all three elements). The crystals were analysed subsequently in situ, using the Rutherford backscattering (RBS) channelling technique. All implants exhibited a large (apparent) substitutional fraction SF = 50-70% when implanted at 293 K, whereas SF = 0 for the implantations at 77 K. The annealing behaviour was also studied. For the crystals implanted at 293 K, the release of impurity atoms (Te, Cs) sets in at temperatures above 750 K and is clearly correlated with radiation damage recovery. Xe-release starts above about 1300 K. The release of Te implanted at 77 K has already begun at 400 K and is nearly complete at 600 K. In this temperature range, no changes in the damage distribution were noticed. These results give the first indication of coherent precipitation of solid rare gases and volatiles in UO(2).
Bibliographic Reference: Paper presented: Nuclear Instrument Methods in Physics Research, Weimar (DE), June 24-28, 1991
Availability: Available from (1) as Paper EN 36211 ORA
Record Number: 199111520 / Last updated on: 1994-12-02
Original language: en
Available languages: en