RESONANCE PHOTOELECTRON-SPECTROSCOPY USING A TUNABLE LASER-PLASMA LIGHT-SOURCE

We report the first resonance photoemission experiments on plutonium m etal, with surface preparation accomplished by means of laser ablation , The photoemission experiments were conducted using the newly commiss ioned tunable light source for transuranic research at Los Alamos. The light source is a tunable, laser plasma system capable of producing p hotons in the energy range 30-150 eV, with a photon flex of order 10(9 ) photons s(-1) at 0.1% bandwidth. First results on delta-phase pluton ium reveal the 5d-5f resonance enhancement to be maximum at a photon e nergy of 113 eV. Lower energy photoemission results show a narrow peak very near the Fermi level, with a linewidth of order 100 meV. This pe ak is verified by resonance photoemission to be of 5f character bat al so having strong 6d-7s contributions. The combination of high-energy r esolution, tunable energies for orbital character determination and su rface sensitivity of the UPS energy range make the laser plasma light source ideal for surface and interface studies. (C) 1998 John Wiley & Sons, Ltd.