FLUORESCENCE-PHOTOION-COINCIDENCE SPECTROSCOPY ON ICN CORE-EXCITED MOLECULES

An experimental setup is presented to measure coincidence spectra between a fluorescence photon (260 nm≤λph≤600 nm) and one or two photoions after core excitation providing information about the dissociation channels leading to excited, fluorescing states. The dissociation of ICN molecules excited in the iodine 4d shell is discussed. Upon resonant excitation the intensity due to the parent ion is found to be negligibly small and the atomic fragments comprise the most important part of the fluorescence intensity. For the first time coincidences between one photon and two photoions have been measured. In general, the observed mean slopes of the double coincidence peaks are consistent with photoelectron-photoion-photoion) measurements on ICN. In the I+/CN+ channel the singly charged iodine atom is found with relatively high percentage in a different excited state than in the I +/C+ or I+/N+ channels. © 1995 American Institute of Physics.