Secondary electron emission yield from uranium surface due to uranium ion bombardment

We have measured the secondary electron emission yield from a uranium surface bombarded by uranium ions from a laser ion source at impact energies of 300-3000 eV. The uranium surface was prepared by the deposition of uranium atoms, and the uranium ion beam was generated from a laser ion source. Secondary electrons were not emitted under a threshold energy of about 1000 eV. Above this threshold energy, the secondary electron emission yield increased linearly with the impact energy, and became 0.12 at the impact energy of 3000 eV. (author)