To cite this version:J M Bizau, C Blancard, M Coreno, D Cubaynes, C Dehon, et al.. Photoionization study of Kr+ and Xe+ ions with the combined use of a merged-beam set-up and an ion trap. Journal of Physics B: Atomic, Molecular and Optical Physics, IOP Publishing, 2011, 44 (5) Introduction:Atomic physics provides unique tools for plasma diagnostics. In particular, based on photoionization studies on ionic species one can deduce essential spectroscopic data for the determination of important plasma parameters such as abundance and temperature. In addition, dipole selection rules allow further simplification of the data by reducing the number of allowed transitions. To be useful, quantities like the energies and oscillator strengths of discrete lines or direct photoionization cross sections must be measured in absolute value with high accuracy for a large number of ionic species and over a wide range of photon energy. Photoionization is also one of the main processes contributing to plasma opacity and radiation transfer inside plasmas.

Gas phase VUV single-photon photoionization spectroscopy of electrospray-produced multiply protonated cytochrome c protein (12 kDa) has been performed by means of coupling a linear quadrupole ion trap with a synchrotron beamline. The thresholds for the ionization of the 8+ and 11+ charge state precursors to radical 9+ and 12+ species were measured to be 12.75 ± 0.10 and 13.51 ± 0.10 eV, respectively.