The Ionisation dynamics of water following oxygen 1s inner-shell excitation

Kuniwake, Miki*; Homma, Kenji*; Gejo, Tatsuo*; Asakura, Yuka*; Harries, J.

When a molecule is irradiated with soft X-rays, an inner-shell electron is excited, leading to the creation of inner-shell vacancy states. De-excitation occurs via processes such as Auger decay and fluorescence. Water is a simple 3-atom molecule, and while its inner-shell excitation processes have been widely studied, there have been few studies on its photo-ionisation dissociation dynamics. Earlier work at SPring-8 revealed the importance of the production of neutral particles in this excitation region. In order to study in detail the production mechanism for metastable atoms, we have compared the kinetic energies of the metasable atoms with those of H ions, and found that they have different excitation photon energy dependencies.