Desorption of ionic species from ice/graphite by femtosecond XUV free-electron laser pulses

作者：Siemer B^*; Hoger T; Rutkowski M; Treusch R; Zacharias H

来源：Journal of Physics: Condensed Matter , 2010, 22(8): 084013.

DOI：10.1088/0953-8984/22/8/084013

We report results of laser desorption from water ice surfaces using XUV pulses from the free-electron laser in Hamburg (FLASH). This XUV to soft x-ray FEL provides femtosecond pulses at 20-200 eV photon energy with pulse energies up to 100 mu J. The interaction of this intense soft x-ray radiation with ice (H(2)O, D(2)O) adsorbed on highly oriented pyrolytic graphite (HOPG) yields the desorption of various ions, particularly H(+) (D(+)), O(+), O(2)(+) and others. For H(+) and O(+) ions linear desorption yields are observed, while for O(2)(+) a highly nonlinear desorption yield with n = (2.5 +/- 0.2) is found. Kinetic energies of 1.8 eV, 559 meV and 390 meV for H(+), O(+), and O(2)(+), respectively, account for only a small part of the available excess energy.

• 出版日期2010-3-3